Bio

Clinical Focus


  • Pediatric Gastroenterology
  • inflammatory bowel diseases
  • complex chronic diseases

Academic Appointments


Administrative Appointments


  • Co-Director, Stanford Children's Inflammatory Bowel Disease Center, Department of Pediatrics (2014 - Present)
  • Co-Chair, PRO-KIIDS Network, Crohn’s & Colitis Foundation of America (2016 - Present)
  • Associate Program Director, Pediatric Gastroenterology Fellowship (2016 - Present)
  • Chair, Utilization Review Committee, Stanford Children's Health (2016 - Present)
  • Chair, Clinical Care & Quality Committee, North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (2015 - Present)
  • Medical Director, Short Stay Infusion Unit, Stanford Children's Health (2014 - Present)
  • Physician Lead, ImproveCareNow Network for Pediatric Inflammatory Bowel Disease, Lucile Packard Children's Hospital (2013 - Present)

Honors & Awards


  • Clinical Research Award, Department of Pediatrics (Stanford) (2013)
  • Clinical Scientist Career Development Award (K08), NIH / NIDDK (2012-2017)
  • Stanford Society of Physician Scholars Research Grant, School of Medicine (2011)
  • Rosa and Marjorie Wann Fellowship Research Award, Lucile Packard Children's Hospital (2010)
  • Resident Research and Scholarly Performance Award, CCMC (2007)
  • Howard Hughes Research Scholar, Howard Hughes Foundation (2000)

Professional Education


  • Board Certification: Pediatric Gastroenterology, American Board of Pediatrics (2011)
  • Fellowship:Stanford University - Gastroenterology Department of Pediatrics (2011) CA
  • MS, Stanford University, Health Services Research (2011)
  • Board Certification: Pediatrics, American Board of Pediatrics (2008)
  • Residency:Steven and Alexandra Cohen Children's Medical Center (2008) NY
  • Medical Education:University of Tennessee College of Medicine (2005) TN
  • BS, Duke University, Chemistry, Biochemistry (2000)

Research & Scholarship

Current Research and Scholarly Interests


My research interests are in the development of effective and cost-effective clinical approaches to treating gastrointestinal diseases, with an emphasis in Crohn's disease and ulcerative colitis. Using large databases, patient-reported outcomes, and decision science (e.g., Markov modeling), my overarching research goal is to optimize the use of various diagnostic and therapeutic strategies to improve patients' health, healthcare delivery, and pharmaco-economics of chronic gastrointestinal diseases - thereby informing patients, clinicians, and policy makers. Aside from inflammatory bowel disease, I am interested in applying available data and translating innovative ideas (e.g., technology, social media, and bioinformatics) to other complex chronic diseases, especially those with child health significance, through collaborative and inter-disciplinary efforts. Recently, we have adapted our investigations into the study of celiac disease, liver transplantation, functional abdominal pain, childhood obesity, acute and chronic diarrhea (e.g., Clostridium difficile infections), and microbiota. Whenever possible, our research attempts to compare the health and economic impact of clinical decisions from a health policy standpoint.

Teaching

2015-16 Courses


Publications

All Publications


  • Cost-effectiveness of adalimumab, infliximab or vedolizumab as first-line biological therapy in moderate-to-severe ulcerative colitis. BMJ open gastroenterology Yokomizo, L., Limketkai, B., Park, K. T. 2016; 3 (1): e000093

    Abstract

    There are no head-to-head randomised controlled trials (RCTs) comparing the effectiveness of biologics in ulcerative colitis (UC). We aimed to assess the cost-effectiveness of adalimumab, infliximab and vedolizumab as first-line agents to induce clinical remission and mucosal healing (MH) in UC.We constructed a decision tree based on a payer's perspective in the USA to estimate the first year costs of adalimumab, infliximab or vedolizumab to achieve clinical remission and MH in patients with moderate-to-severe UC. Transition probabilities were derived from ACT, ULTRA and GEMINI RCT data. Costs were derived from Medicare reimbursement rates and wholesale drug prices.Assuming a biological-naïve cohort, infliximab 5 mg/kg every 8 weeks was more cost-effective ($99 171 per MH achieved) than adalimumab 40 mg every other week ($316 378 per MH achieved) and vedolizumab every 8 weeks ($301 969 per MH achieved) at 1 year. Non-drug administration cost of infliximab exceeding $1974 per infusion would make adalimumab more cost-effective. First-line UC therapy with vedolizumab would be cost-effective if the drug acquisition price was <$2537 for each 300 mg administration during the 1-year time horizon.If non-drug costs of infliximab administration are not excessive (<$2000), infliximab is the most cost-effective first-line biologic for moderate-to-severe UC. Exceeding this threshold infusion-related cost would make adalimumab the more cost-effective therapy. Considering its drug costs in the USA, vedolizumab appears to be appropriately used as a second-line biologic after antitumour necrosis factor failure.

    View details for DOI 10.1136/bmjgast-2016-000093

    View details for PubMedID 27195130

  • Infliximab Dosing Strategies and Predicted Trough Exposure in Children with Crohn's Disease. Journal of pediatric gastroenterology and nutrition Frymoyer, A., Piester, T. L., Park, K. T. 2016

    Abstract

    Standard infliximab maintenance dosing of 5 mg/kg every 8 weeks may be inadequate to consistently achieve sufficient drug exposure to minimize loss of response or treatment failure in pediatric Crohn's disease (CD). We aimed to determine the predicted infliximab trough concentrations in children with CD during maintenance therapy and the percentage of patients achieving target trough concentration >3 μg/ml.A Monte Carlo simulation analysis was constructed using a published population pharmacokinetic model based on data from 112 children in the REACH trial. We assessed maintenance dosing strategies of 5, 7.5, and 10 mg/kg at dosing intervals of every 4, 6, and 8 weeks for children that differed by age, weight, albumin level, and concomitant immunomodulator therapy.Based on the index case of a 10 year old with CD receiving standard infliximab dosing with concomitant immunomodulator therapy, the median (IQR) simulated infliximab trough concentration at week 14 was 1.3 (0.5-2.7) μg/ml, and 2.4 (1.0-4.8) μg/ml for albumin levels of 3 and 4 g/dl, respectively. Among 1000 simulated children in the model, trough concentration >3 μg/ml at week 14 was achieved 21% and 41% of the time for albumin levels of 3 and 4 g/dl, respectively.Standard infliximab maintenance dosing in children with CD is predicted to frequently result in inadequate exposure, especially when albumin levels are low. Optimized dosing strategies for individual patients are needed to achieve sufficient drug exposure during infliximab maintenance therapy.

    View details for DOI 10.1097/MPG.0000000000001123

    View details for PubMedID 26890885

  • Out-of-pocket Cost Burden in Pediatric Inflammatory Bowel Disease: A Cross-sectional Cohort Analysis INFLAMMATORY BOWEL DISEASES Sin, A. T., Damman, J. L., Ziring, D. A., Gleghorn, E. E., Garcia-Careaga, M. G., Gugig, R. R., Hunter, A. K., Burgis, J. C., Bass, D. M., Park, K. T. 2015; 21 (6): 1368-1377

    Abstract

    Pediatric inflammatory bowel disease (IBD), consisting of Crohn's disease (CD) and ulcerative colitis (UC), can result in significant morbidity requiring frequent health care utilization. Although it is known that the overall financial impact of pediatric IBD is significant, the direct out-of-pocket (OOP) cost burden on the parents of children with IBD has not been explored. We hypothesized that affected children with a more relapsing disease course and families in lower income strata, ineligible for need-based assistance programs, disparately absorb ongoing financial stress.We completed a cross-sectional analysis among parents of children with IBD residing in California using an online HIPAA-secure Qualtrics survey. Multicenter recruitment occurred between December 4, 2013 and September 18, 2014 at the point-of-care from site investigators, informational flyers distributed at regional CCFA conferences, and social media campaigns equally targeting Northern, Central, and Southern California. IBD-, patient-, and family-specific information were collected from the parents of pediatric patients with IBD patients younger than 18 years of age at time of study, carry a confirmed diagnosis of CD or UC, reside in and receive pediatric gastroenterology care in California, and do not have other chronic diseases requiring ongoing medical care.We collected 150 unique surveys from parents of children with IBD (67 CD; 83 UC). The median patient age was 14 years for both CD and UC, with an overall 3.7 years (SD 2.8 yr) difference between survey completion and time of IBD diagnosis. Annually, 63.6%, 28.6%, and 5.3% of families had an OOP cost burden >$500, >$1000, and >5000, respectively. Approximately one-third (36.0%) of patients had emergency department (ED) visits over the past year, with 59.2% of these patients spending >$500 on emergency department copays, including 11.1% who spent >$5000. Although 43.3% contributed <$500 on procedure and test costs, 20.0% spent >$2000 in the past year. Families with household income between $50,000 and $100,000 had a statistically significant probability (80.6%) of higher annual OOP costs than families with lower income <$50,000 (20.0%; P < 0.0001) or higher income >$100,000 (64.6%; P < 0.05). Multivariate analysis revealed that clinical variables associated with uncontrolled IBD states correlated to higher OOP cost burden. Annual OOP costs were more likely to be >$500 among patients who had increased spending on procedures and tests (odds ratio [OR], 5.63; 95% confidence interval [CI], 2.73-11.63), prednisone course required over the past year (OR, 3.19; 95% CI, 1.02-9.92), at least 1 emergency department visit for IBD symptoms (OR, 2.84; 95% CI, 1.33-6.06), at least 4 or more outpatient primary medical doctor visits for IBD symptoms (OR, 2.82; 95% CI, 1.40-5.68), and history of 4 or more lifetime hospitalizations for acute IBD care (OR, 2.60; 95% CI, 1.13-5.96).Previously undocumented, a high proportion of pediatric IBD families incur substantial OOP cost burden. Patients who are frequently in relapsing and uncontrolled IBD states require more acute care services and sustain higher OOP cost burden. Lower middle income parents of children with IBD ineligible for need-based assistance may be particularly at risk for financial stress from OOP costs related to ongoing medical care.

    View details for DOI 10.1097/MIB.0000000000000374

    View details for Web of Science ID 000355315800020

  • Health Insurance Paid Costs and Drivers of Costs for Patients With Crohn's Disease in the United States. The American journal of gastroenterology Park, K. T., Colletti, R. B., Rubin, D. T., Sharma, B. K., Thompson, A., Krueger, A. 2015

    Abstract

    The cost of medical care for Crohn's disease (CD) and comorbidities in the era of biologics is unclear. We examined insurance claims data from US health plans to understand this relationship.Longitudinal CD patient data and reimbursement information from 11 health plans engaged with Accordant Health Services between 2011 and 2013 were analyzed. The analysis considered data for all CD patients and for the patient subgroup ≤20 years and >20 years of age. Descriptive statistics measured the mean health-plan paid costs per patient, the relative cost contribution of anti-tumor necrosis factor (TNF) agents, and health care costs for 31 specific comorbid conditions among CD patients.Overall, there were 5,090 CD patients (57% women) of which 587 CD patients were ≤20 years of age. The mean health-plan paid cost per member per year was $18,637 (s.d. $32,023) for all CD patients, $22,796 (s.d. $ 41,905) for CD patients ≤20 years, and $18,095 (s.d. $30,065) for patients >20 years of age. Twenty-eight percent of CD patients accounted for 80% of total costs. No differences were found in costs based on gender. Increased health-plan paid costs were significantly correlated with the number of comorbid conditions across all ages. Pharmacy utilization costs account for nearly one-half (45.5%) of the total CD-attributable costs, exceeding inpatient care costs. Anti-TNF agents alone comprised nearly one-third (29.5%) of total costs. Aside from anti-TNF costs, other major categories of expense were as follows: inpatient 23.1%, outpatient hospital setting 15.7%, and MD office 8.2%.Total health-care costs in CD exceed previous estimates, with the majority of costs being allocated to a relatively small subgroup of patients. Pharmacy utilization costs, owing to anti-TNF use, result in increasing total health-care costs and currently exceed costs for inpatient care. Pragmatic strategies to encourage gastroenterologists in the best clinical practice of optimizing anti-TNF use-in particular for younger age patients and those with multiple comorbidities-are necessary to reduce avoidable pharmacy utilization and inpatient care costs.Am J Gastroenterol advance online publication, 21 July 2015; doi:10.1038/ajg.2015.207.

    View details for DOI 10.1038/ajg.2015.207

    View details for PubMedID 26195179

  • Effectiveness and Cost-effectiveness of Measuring Fecal Calprotectin in Diagnosis of Inflammatory Bowel Disease in Adults and Children. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association Yang, Z., Clark, N., Park, K. T. 2014; 12 (2): 253-262.e2

    Abstract

    The level of fecal calprotectin (FC) can predict the onset of inflammatory bowel disease (IBD) with high accuracy and precision. We evaluated the cost-effectiveness of using measurements of FC to identify adults and children who require endoscopic confirmation of IBD.We constructed a decision analytic tree to compare the cost-effectiveness of measuring FC before endoscopy examination with that of direct endoscopic evaluation alone. A second decision analytic tree was constructed to evaluate the cost-effectiveness of FC cutoff levels of 100 μg/g vs 50 μg/g (typically used to screen for intestinal inflammation). The primary outcome measure was the incremental cost required to avoid 1 false-negative result by using FC level to diagnose new-onset IBD.In adults, FC screening saved $417/patient but delayed diagnosis for 2.2/32 patients with IBD among 100 screened patients. In children, FC screening saved $300/patient but delayed diagnosis for 4.8/61 patients with IBD among 100 screened patients. If endoscopic biopsy analysis remained the standard for diagnosis, direct endoscopic evaluation would cost an additional $18,955 in adults and $6250 in children to avoid 1 false-negative result from FC screening. Sensitivity analyses showed that cost-effectiveness of FC screening varied with the sensitivity of the test and the pre-test probability of IBD in adults and children. Pre-test probabilities for IBD of ≤75% in adults and ≤65% in children made FC screening cost-effective, but it was cost-ineffective if the probabilities were ≥85% and ≥78% in adults and children, respectively. Compared with the FC cutoff level of 100 μg/g, the cutoff level of 50 μg/g cost an additional $55 and $43 for adults and children, respectively, but it yielded 2.4 and 6.1 additional accurate diagnoses of IBD per 100 screened adults and children, respectively.Screening adults and children to measure fecal levels of calprotectin is effective and cost-effective in identifying those with IBD on a per-case basis when the pre-test probability is ≤75% for adults and ≤65% for children. The utility of the test is greater for adults than children. Increasing the FC cutoff level to ≥50 μg/g increases diagnostic accuracy without substantially increasing total cost.

    View details for DOI 10.1016/j.cgh.2013.06.028

    View details for PubMedID 23883663

  • Cost-Effectiveness of Early Colectomy With Ileal Pouch-Anal Anastamosis Versus Standard Medical Therapy in Severe Ulcerative Colitis ANNALS OF SURGERY Park, K. T., Tsai, R., Perez, F., Cipriano, L. E., Bass, D., Garber, A. M. 2012; 256 (1): 117-124

    Abstract

    Inflammatory bowel diseases are costly chronic gastrointestinal diseases. We aimed to determine whether immediate colectomy with ileal pouch-anal anastamosis (IPAA) after diagnosis of severe ulcerative colitis (UC) was cost-effective compared to the standard medical therapy.We created a Markov model simulating 2 cohorts of 21-year-old patients with severe UC, following them until 100 years of age or death, comparing early colectomy with IPAA strategy to the standard medical therapy strategy. Deterministic and probabilistic analyses were performed.Standard medical care accrued a discounted lifetime cost of $236,370 per patient. In contrast, early colectomy with IPAA accrued a discounted lifetime cost of $147,763 per patient. Lifetime quality-adjusted life-years gained (QALY-gained) for standard medical therapy was 20.78, while QALY-gained for early colectomy with IPAA was 20.72. The resulting incremental cost-effectiveness ratio (?costs/?QALY) was approximately $1.5 million per QALY-gained. Results were robust to one-way sensitivity analyses for all variables in the model. Quality-of-life after colectomy with IPAA was the most sensitive variable impacting cost-effectiveness. A low utility value of less than 0.7 after colectomy with IPAA was necessary for the colectomy with IPAA strategy to be cost-ineffective.Under the appropriate clinical settings, early colectomy with IPAA after diagnosis of severe UC reduces health care expenditures and provides comparable quality of life compared to exhaustive standard medical therapy.

    View details for DOI 10.1097/SLA.0b013e3182445321

    View details for Web of Science ID 000306083300020

    View details for PubMedID 22270693

  • Text Messaging Improves Participation in Laboratory Testing in Adolescent Liver Transplant Patients. Journal of participatory medicine McKenzie, R. B., Berquist, W. E., Foley, M. A., Park, K. T., Windsheimer, J. E., Litt, I. F. ; 7

    Abstract

    In solid organ transplant patients, non-participation in all aspects of the medical regimen is a prevalent problem associated with adverse consequences particularly in the adolescent and young adult (AYA) age group. This study is the first to evaluate the feasibility, utility and impact of a text messaging (TM) intervention to improve participation in laboratory testing in adolescent liver transplant patients.AYA patients, aged 12 to 21 years, were recruited for a prospective pilot trial evaluating a TM intervention delivered over a 1-year period. The intervention involved automated TM reminders with feedback administered according to a prescribed laboratory testing frequency. Participation rate in laboratory testing after the intervention was compared to the year prior. Patient responses and feedback by text and survey were used to assess feasibility, acceptability and use of the intervention.Forty-two patients were recruited and 33 patients remained enrolled for the study duration. Recipients of the TM intervention demonstrated a significant improvement in participation rate in laboratory testing from 58% to 78% (P<.001). This rate was also significantly higher than in non-intervention controls (P=.003). There was a high acceptability, response rate and a significant correlation with reported versus actual completion of laboratory tests by TM.TM reminders significantly improved participation in laboratory testing in AYA liver transplant patients. The intervention demonstrated feasibility, acceptability, and use with a high proportion of patients who engaged in and perceived a benefit from using this technology.

    View details for PubMedID 26213633

  • Patient and Family Access to Electronic Health Records: A Key Ingredient for a Pediatric Learning Health System. Journal of participatory medicine Park, K., Park, M. D., Longhurst, C. A. ; 7

    View details for PubMedID 25664199

  • Spanish and English Language Symposia to Enhance Activation in Pediatric Inflammatory Bowel Disease. Journal of pediatric gastroenterology and nutrition Martin, M., Garcia, M., Christofferson, M., Bensen, R., Yeh, A. M., Park, K. T. 2016

    Abstract

    Patient activation is an important consideration for improved health outcomes in the management of chronic diseases. Limited English proficiency (LEP) among patients and primary care providers has been shown to be a predictor for worse health across disease states. We aimed to determine the baseline patient activation measure (PAM) among Spanish-speaking (SP) and English-speaking (ES) pediatric IBD patients and parents, and to describe the feasibility and efficacy of a novel peer-group education symposium designed to enhance patient activation as measured with the PAM.Two separate half-day educational symposia in either Spanish or English were presented and moderated by 2 native Spanish-speaking physicians. Content for each of the presentations were highly standardized and interactive, designed to address each of the activation domains (self-management, collaboration with a health care provider, maintenance of function and prevention of disease exacerbation, and appropriate access to high-quality care). Descriptive statistics were used to describe changes between pre- and post-symposium PAM trends.11 primarily SP and 21 ES families participated in their respective symposium. Paired pre- and post-PAM scores were available from 24 pediatric IBD patients (8 SP; 16 ES) and 41 parents (15 SP; 26 ES). The mean age for SP and ES patients was 11.6 and 12.0 years, and female gender in 80% and 62%, respectively. Paired pre- and post-PAM scores for all participants (n = 65) were analyzed. PAM scores uniformly increased in all 4 groups after the symposia (SP-patients 59.1 to 70.3, P = 0.05; SP-parents 69.8 to 75.2, P = 0.2; ES-patients 59.9 to 64.0, P = 0.08; ES-parents 61.9 to 69.1, P = 0.002), although only the ES-parents group had sufficient sample size (n = 26) to achieve statistical significance. The overall cohort had an aggregate increase from pre-PAM of 62.9 (SD 14.5) to post-PAM of 69.4 (SD 13.9) (<0.001).We describe a novel peer-group educational symposium presented in Spanish and English languages to increase patient and parent activation in pediatric IBD patients and their care-giving parents. The use of PAM to assess levels of activation appears to be feasible and effective in these groups.

    View details for DOI 10.1097/MPG.0000000000001191

    View details for PubMedID 27031374

  • Response to strict and liberalized specific carbohydrate diet in pediatric Crohn's disease. World journal of gastroenterology Burgis, J. C., Nguyen, K., Park, K. T., Cox, K. 2016; 22 (6): 2111-7

    Abstract

    To investigate the specific carbohydrate diet (SCD) as nutritional therapy for maintenance of remission in pediatric Crohn's disease (CD).Retrospective chart review was conducted in 11 pediatric patients with CD who initiated the SCD as therapy at time of diagnosis or flare. Two groups defined as SCD simple (diet alone, antibiotics or 5-ASA) or SCD with immunomodulators (corticosteroids and/or stable thiopurine dosing) were followed for one year and compared on disease characteristics, laboratory values and anthropometrics.The mean age at start of the SCD was 11.8 ± 3.0 years (range 6.6-17.6 years) with five patients starting the SCD within 5 wk of diagnosis. Three patients maintained a strict SCD diet for the study period and the mean time for liberalization was 7.7 ± 4.0 mo (range 1-12) for the remaining patients. In both groups, hematocrit, albumin and ESR values improved while on strict SCD and appeared stable after liberalization (P-value 0.006, 0.002, 0.002 respectively). The majority of children gained in weight and height percentile while on strict SCD, with small loss in weight percentile documented with liberalization.Disease control may be attainable with the SCD in pediatric CD. Further studies are needed to assess adherence, impact on mucosal healing and growth.

    View details for DOI 10.3748/wjg.v22.i6.2111

    View details for PubMedID 26877615

  • Pediatric Resident Workload Intensity and Variability. Pediatrics Was, A., Blankenburg, R., Park, K. T. 2016

    Abstract

    Research on resident workloads has focused primarily on the quantity of hours worked, rather than the content of those hours or the variability among residents. We hypothesize that there are statistically significant variations in resident workloads and better understanding of workload intensity could improve resident education.The Stanford Children's Health research database was queried for all electronic notes and orders written by pediatric residents from June 2012 to March 2014. The dataset was narrowed to ensure an accurate comparison among residents. A survey was used to determine residents' self-perceived workload intensity. Variability of total notes written and orders entered was analyzed by χ(2) test and a Monte Carlo simulation. Linear regression was used to analyze the correlation between note-writing and order-entry workload intensity.A total of 20 280 notes and 112 214 orders were written by 26 pediatric interns during 6 core rotations between June 2012 and June 2013. Both order-entry and note-writing workload intensity showed highly significant (P < .001) variability among residents. "High workload" residents, defined as the top quartile of total workload intensity, wrote 91% more orders and 19% more notes than "low workload" residents in the bottom quartile. Statistically significant correlation was observed between note-writing and order-entry workload intensity (R(2) = 0.22; P = .02). There was no significant correlation between residents' self-perceived workload intensity and their objective workload.Significant variations in workload exist among pediatric residents. This may contribute to heterogeneous educational opportunities, physician wellness, and quality of patient care.

    View details for DOI 10.1542/peds.2015-4371

    View details for PubMedID 27358473

  • Associations of Elevated Liver Enzymes among Hospitalized Adolescents with Anorexia Nervosa JOURNAL OF PEDIATRICS Nagata, J. M., Park, K. T., Colditz, K., Golden, N. H. 2015; 166 (2): 439-?

    Abstract

    To analyze the prevalence, predictors, and evolution of increased liver enzymes in a large sample of adolescents hospitalized with anorexia nervosa (AN).Electronic medical records of all subjects 10-22 years of age with AN, first admitted to a tertiary children's hospital from January 2007 to December 2012, were reviewed retrospectively. Demographic factors, anthropometric factors, initial prescribed calories, and alanine aminotransferase levels were recorded. Multivariate analysis was performed to assess the effect of sex, degree of malnutrition, and initial calories prescribed on having alanine aminotransferase ≥40 IU/L.A total of 356 subjects met eligibility criteria (age 16.1 ± 2.4; 89.0% female; admission body mass index [BMI] 15.9 ± 1.9; admission percentage median BMI 78.2 ± 8.5), with elevated liver enzymes present in 37.0% on admission and in 41.1% at any point during the hospitalization. Lower percentage median BMI (aOR 0.96; 95% CI 0.93-0.98) and male sex (aOR 0.45; 95% CI 0.22-0.94) were significantly associated with odds of elevated liver enzymes on admission. Higher initial prescribed calories were associated with odds of elevated liver enzymes after admission (aOR 1.81; 95% CI 1.04-3.18).In this study of AN and elevated liver enzymes, the degree of malnutrition and male sex predicted elevated liver enzymes on admission but initial prescribed calories also may be associated with elevated liver enzymes after admission in a small proportion of patients. Future research should better characterize the evolution of elevated liver enzymes in patients hospitalized with AN undergoing refeeding.

    View details for DOI 10.1016/j.jpeds.2014.10.048

    View details for Web of Science ID 000348496200047

    View details for PubMedID 25477162

  • Rapid cessation of acute diarrhea using a novel solution of bioactive polyphenols: a randomized trial in Nicaraguan children. PeerJ Dover, A., Patel, N., Park, K. T. 2015; 3: e969

    Abstract

    Goal. We assessed the effectiveness of bioactive polyphenols contained in solution (LX) to restore normal bowel function in pediatric patients with acute diarrhea. Background. While providing oral rehydration solution (ORS) is standard treatment for diarrhea in developing countries, plant-derived products have been shown to positively affect intestinal function. If a supplement to ORS resolves diarrhea more rapidly than ORS alone, it is an improvement to current care. Study. In a randomized, double-blind, placebo-controlled cross-over study, 61 pediatric patients with uncontrolled diarrhea were randomized to receive either ORS + LX on day 1 and then ORS + water on day 2 (study arm) or ORS + water on day 1 and then ORS + LX on day 2 (control arm). Time to resolution and number of bowel movements were recorded. Results. On day 1, the mean time to diarrhea resolution was 3.1 h (study arm) versus 9.2 h (control arm) (p = 0.002). In the study arm, 60% of patients had normal stool at their first bowel movement after consumption of the phenolic redoxigen solution (LX). On day 2, patients in the study arm continued to have normal stool while patients in the control arm achieved normal stool within 24 h after consuming the test solution. Patients in the control arm experienced a reduction in the mean number of bowel movements from day 1 to day 2 after consuming the test solution (p = 0.0001). No adverse events were observed. Conclusions. Significant decreases in bowel movement frequency and rapid normalization of stool consistency were observed with consumption of this novel solution.

    View details for DOI 10.7717/peerj.969

    View details for PubMedID 26038724

  • Acupuncture and Integrative Medicine for Pediatric Gastroesophageal Reflux and Functional Dyspepsia Medical Acupuncture Kanak, M., Park, K. T., Yeh, A. M. 2015
  • Health outcomes in US children with abdominal pain at major emergency departments associated with race and socioeconomic status. PloS one Wang, L., Haberland, C., Thurm, C., Bhattacharya, J., Park, K. T. 2015; 10 (8)

    Abstract

    Over 9.6 million ED visits occur annually for abdominal pain in the US, but little is known about the medical outcomes of these patients based on demographics. We aimed to identify disparities in outcomes among children presenting to the ED with abdominal pain linked to race and SES.Data from 4.2 million pediatric encounters of abdominal pain were analyzed from 43 tertiary US children's hospitals, including 2.0 million encounters in the emergency department during 2004-2011. Abdominal pain was categorized as functional or organic abdominal pain. Appendicitis (with and without perforation) was used as a surrogate for abdominal pain requiring emergent care. Multivariate analysis estimated likelihood of hospitalizations, radiologic imaging, ICU admissions, appendicitis, appendicitis with perforation, and time to surgery and hospital discharge.Black and low income children had increased odds of perforated appendicitis (aOR, 1.42, 95% CI, 1.32- 1.53; aOR, 1.20, 95% CI 1.14 - 1.25). Blacks had increased odds of an ICU admission (aOR, 1.92, 95% CI 1.53 - 2.42) and longer lengths of stay (aHR, 0.91, 95% CI 0.86 - 0.96) than Whites. Minorities and low income also had lower rates of imaging for their appendicitis, including CT scans. The combined effect of race and income on perforated appendicitis, hospitalization, and time to surgery was greater than either separately.Based on race and SES, disparity of health outcomes exists in the acute ED setting among children presenting with abdominal pain, with differences in appendicitis with perforation, length of stay, and time until surgery.

    View details for DOI 10.1371/journal.pone.0132758

    View details for PubMedID 26267816

  • Misdiagnosis of Alpha-1 Antitrypsin Phenotype in an Infant with CMV Infection and Liver Failure DIGESTIVE DISEASES AND SCIENCES Arias, P., Kerner, J., Christofferson, M., Berquist, W., Park, K. T. 2014; 59 (8): 1710-1713
  • Characteristics and Direct Costs of Academic Pediatric Subspecialty Outpatient No-Show Events JOURNAL FOR HEALTHCARE QUALITY Perez, F. D., Xie, J., Sin, A., Tsai, R., Sanders, L., Cox, K., Haberland, C. A., Park, K. T. 2014; 36 (4): 32-42

    Abstract

    BACKGROUND: Clinic no shows (NS) create a lost opportunity for provider-patient interaction and impose a financial burden to the healthcare system and on society. We aimed to: (1) to determine the clinical and demographic factors associated with increased NS rates at a children's hospital's subsubspecialty clinics and (2) to estimate the direct institutional financial costs associated with NS events. METHODS: A comprehensive database was generated from all clinic encounters for 15 subspecialty outpatient clinics (five surgical and 10 medical) between September 12, 2005 and December 30, 2010. Multivariate logistic regressions were performed to identify the variables associated with NS events. Direct costs of NS events were estimated using annual revenue for each clinic. RESULTS: A total of 284,275 encounters and 17,024 NS events were available for analysis. Public insurance coverage (Medicaid and Title V), compared to private insurance or self-pay status, was associated with an increased likelihood NS (OR 2.19, 95% CI 2.10-2.28, p < 0.0005 for Medicaid; OR 1.56, 95% CI 1.50-1.62, p < 0.0005 for Title V). Compared to patients 21-30 years of age, patients <12 years (OR 2.08, 95% CI 1.77-2.45, p < 0.0005) had increased likelihood of NS. Scheduled visits with medical subspecialists were more likely than surgical subspecialty visits to result in a NS (OR 1.69, 95% CI 1.63-1.75, p < 0.0005). The predicted annualized lost revenue associated with NS visits was estimated at $730,000 from the 15 clinics analyzed, approximately $210 per NS event. CONCLUSION: Pediatric subspecialty NS events are common, costly, and potentially preventable.

    View details for Web of Science ID 000348450800003

    View details for PubMedID 23551280

  • Utilization Trends of Anti-TNF Agents and Health Outcomes in Adults and Children with Inflammatory Bowel Diseases: A Single-center Experience INFLAMMATORY BOWEL DISEASES Park, K. T., Sin, A., Wu, M., Bass, D., Bhattacharya, J. 2014; 20 (7): 1242-1249

    Abstract

    Utilization trends and health effects of infliximab and adalimumab in inflammatory bowel disease (IBD) are incompletely understood. We aimed to describe utilization trends of these 2 anti-tumor necrosis factor (TNF) agents, determine the correlation between utilization with rates of hospitalization and surgery and describe differences in use between adults and children.Longitudinal data were analyzed for drug utilization, hospitalization, and abdominal surgery. Descriptive statistics were used to show trends, and utilization quotients were compared for standardization. Multivariate logistic regression analysis assessed the association between drug use and rates of hospitalization and surgery.Four hundred thirty-eight pediatric and 2514 adult patients with IBD generated a total of 51,882 inpatient and outpatient encounters, representing 1185 Crohn's disease, 1531 ulcerative colitis, and 236 indeterminate colitis patients. From 2007 through 2012, utilization quotients declined for hospitalization but remained unchanged for surgery; adalimumab saw a 3-fold increase, despite continued dominance of infliximab. Median band and mean fitted plots showed downward hospitalization trends from 2006 to 2012. Utilization of infliximab peaked in 2008, Q4 with gradual decline to 2012, Q2; and adalimumab showed moderate increased utilization since 2007, Q1. Use of infliximab (odds ratio [OR], 0.76; 95% confidence interval [CI], 0.70-0.83) and adalimumab (OR, 0.79; 95% CI, 0.72-0.87) was associated with decreased hospitalization risk but not associated with reduced abdominal surgery risk. Children had increased hospitalization (OR, 2.68; 95% CI, 2.49-2.88) but decreased risk for abdominal surgery (OR, 0.57; 95% CI, 0.46-0.70).Current infliximab use remains substantially greater than adalimumab use, despite recent increased use of adalimumab. Although trends for hospitalization for IBD are decreasing, it is not reflected in abdominal surgery rates in a tertiary IBD referral center.

    View details for DOI 10.1097/MIB.0000000000000061

    View details for Web of Science ID 000337750000018

    View details for PubMedID 24846718

  • Implementable Strategies and Exploratory Considerations to Reduce Costs Associated with Anti-TNF Therapy in Inflammatory Bowel Disease. Inflammatory bowel diseases Park, K. T., Crandall, W. V., Fridge, J., Leibowitz, I. H., Tsou, M., Dykes, D. M., Hoffenberg, E. J., Kappelman, M. D., Colletti, R. B. 2014

    Abstract

    : A health care system is needed where care is based on the best available evidence and is delivered reliably, efficiently, and less expensively (best care at lower cost). In gastroenterology, anti-tumor necrosis factor agents represent the most effective medical therapeutic option for patients with moderate-to-severe inflammatory bowel disease (IBD), but are very expensive and account for nearly a quarter of the cost of IBD care, representing a major area of present and future impact in direct health care costs. The ImproveCareNow Network, consisting of over 55 pediatric IBD centers, seeks ways to improve the value of care in IBD, curtailing unnecessary costs and promoting better health outcomes through systematic and incremental quality improvement initiatives. This report summarizes the key evidence to facilitate the cost-effective use of anti-tumor necrosis factor agents for patients with IBD. Our review outlines the scientific rationale for initiating cost-reducing measures in anti-tumor necrosis factor use and focuses on 3 implementable strategies and 4 exploratory considerations through practical clinical guidelines, as supported by existing evidence. Implementable strategies can be readily integrated into today's daily practice, whereas exploratory considerations can guide research to support future implementation.

    View details for DOI 10.1097/01.MIB.0000441349.40193.aa

    View details for PubMedID 24451222

  • Rationale for Using Social Media to Collect Patient-Reported Outcomes in Patients with Celiac Disease. Journal of gastrointestinal & digestive system Park, K., Harris, M., Khavari, N., Khosla, C. 2014; 4 (1)

    Abstract

    Patients with celiac disease (CD) are increasingly interconnected through social media, exchanging patient experiences and health-tracking information between individuals through various web-based platforms. Social media represents potentially unique communication interface between gastroenterologists and active social media users - especially young adults and adolescents with celiac disease-regarding adherence to the strict gluten-free diet, gastrointestinal symptoms, and meaningful discussion about disease management. Yet, various social media platforms may be underutilized for research purposes to collect patient-reported outcomes data. In this commentary, we summarize the scientific rationale and potential for future growth of social media in patient-reported outcomes research, focusing on college freshmen with celiac disease as a case study and provide overview of the methodological approach. Finally, we discuss how social media may impact patient care in the future through increasing mobile technology use.

    View details for DOI 10.4172/2161-069X.1000166

    View details for PubMedID 25392743

  • Differences in healthcare expenditures for inflammatory bowel disease by insurance status, income, and clinical care setting. PeerJ Park, M. D., Bhattacharya, J., Park, K. 2014; 2

    Abstract

    Background. Socioeconomic factors and insurance status have not been correlated with differential use of healthcare services in inflammatory bowel disease (IBD). Aim. To describe IBD-related expenditures based on insurance and household income with the use of inpatient, outpatient, emergency, and office-based services, and prescribed medications in the United States (US). Methods. We evaluated the Medical Expenditure Panel Survey from 1996 to 2011 of individuals with Crohn's disease (CD) or ulcerative colitis (UC). Nationally weighted means, proportions, and multivariate regression models examined the relationships between income and insurance status with expenditures. Results. Annual per capita mean expenditures for CD, UC, and all IBD were $10,364 (N = 238), $7,827 (N = 95), and $9,528, respectively, significantly higher than non-IBD ($4,314, N = 276, 372, p < 0.05). Publicly insured patients incurred the highest costs ($18,067) over privately insured ($8,014, p < 0.05) or uninsured patients ($5,129, p < 0.05). Among all IBD patients, inpatient care composed the highest proportion of costs ($3,392, p < 0.05). Inpatient costs were disproportionately higher for publicly insured patients. Public insurance had higher odds of total costs than private (OR 2.13, CI [1.08-4.19]) or no insurance (OR 4.94, CI [1.26-19.47]), with increased odds for inpatient and emergency care. Private insurance had higher costs associated with outpatient care, office-based care, and prescribed medicines. Low-income patients had lower costs associated with outpatient (OR 0.38, CI [0.15-0.95]) and office-based care (OR 0.21, CI [0.07-0.62]). Conclusions. In the US, high inpatient utilization among publicly insured patients is a previously unrecognized driver of high IBD costs. Bridging this health services gap between SES strata for acute care services may curtail direct IBD-related costs.

    View details for DOI 10.7717/peerj.587

    View details for PubMedID 25279267

  • Appropriateness of Emergency Department Use in Pediatric Inflammatory Bowel Disease: A Quality Improvement Opportunity. Journal of pediatric gastroenterology and nutrition Hoffenberg, E. J., Park, K. T., Dykes, D. M., Fridge, J., Kappelman, M. D., Leibowitz, I., Tsou, M., Colletti, R. B. 2014

    Abstract

    We sought to characterize emergency department (ED) encounters for pediatric inflammatory bowel disease (IBD) to identify areas for prevention.Retrospective chart review of 5 consecutive ED encounters at 7 centers.Of 35 unique encounters by 32 subjects, 3 main factors contributed to ED utilization: disease severity or course, day or time of care, and physician instruction. Of the ED encounters, approximately one-fifth were judged medically unnecessary, and one-half avoidable in a more optimal health care system.ED visits by pediatric IBD patients may be reduced in a more optimal health care system.

    View details for DOI 10.1097/MPG.0000000000000457

    View details for PubMedID 24918980

  • The significance of serum total immunoglobulin E for in vitro diagnosis of allergic rhinitis INTERNATIONAL FORUM OF ALLERGY & RHINOLOGY Chung, D., Park, K. T., Yarlagadda, B., Davis, E. M., Platt, M. 2014; 4 (1): 56-60

    Abstract

    Allergic rhinitis is diagnosed by clinical parameters with no widely accepted screening test. Measurement of total serum immunoglobulin E (IgE) has limited use in the general population due to a low negative predictive value. The value of total IgE level in select populations undergoing in vitro allergy testing remains unknown. The aim of this study is to determine the utility of total serum IgE in the in vitro diagnosis of allergic rhinitis.A retrospective chart review of patients undergoing testing for allergic rhinitis was performed. Clinical parameters, total IgE level, and enzyme-linked immunosorbent assay (ELISA) for serum-specific IgE levels were analyzed with multivariate logistic regression. The positive and negative predictive values and a receiver operating characteristic (ROC) curve were used to assess the utility of total IgE in predicting serum-specific IgE test results.Records from 1073 patients were reviewed. ROC curve for total IgE >150 IU/mL (Σ 0.88) indicates good discrimination in identifying patients with sensitization by in vitro testing, whereas low total IgE level had strong negative predictive value (0.87, IgE <10) in identifying negative specific IgE testing. Multivariate logistic regression showed that differences in covariables did not significantly change the odds of a positive in vitro allergy test panel.Serum total IgE level is useful in the in vitro diagnosis of allergic rhinitis. In vitro testing for specific IgE may be unnecessary in patients with low serum total IgE, whereas high total IgE level suggests that in vitro testing would confirm specific sensitizations in patients with allergic rhinitis.

    View details for DOI 10.1002/alr.21240

    View details for Web of Science ID 000329152400011

    View details for PubMedID 24227797

  • Cost-effectiveness of Universal Serologic Screening to Prevent Nontraumatic Hip and Vertebral Fractures in Patients With Celiac Disease CLINICAL GASTROENTEROLOGY AND HEPATOLOGY Park, K. T., Tsai, R., Wang, L., Khavari, N., Bachrach, L., Bass, D. 2013; 11 (6): 645-653

    Abstract

    Patients with asymptomatic or poorly managed celiac disease can experience bone loss, placing them at risk for hip and vertebral fractures. We analyzed the cost-effectiveness of universal serologic screening (USS) vs symptomatic at-risk screening (SAS) strategies for celiac disease because of the risk of nontraumatic hip and vertebral fractures if untreated or undiagnosed.We developed a lifetime Markov model of the screening strategies, each with male or female cohorts of 1000 patients who were 12 years old when screening began. We screened serum samples for levels of immunoglobulin A, compared with tissue transglutaminase and total immunoglobulin A, and findings were confirmed by mucosal biopsy. Transition probabilities and quality of life estimates were obtained from the literature. We used generalizable cost estimates and Medicare reimbursement rates and ran deterministic and probabilistic sensitivity analyses.For men, the average lifetime costs were $8532 and $8472 for USS and SAS strategies, respectively, corresponding to average quality-adjusted life year gains of 25.511 and 25.515. Similarly for women, costs were $11,383 and $11,328 for USS and SAS strategies, respectively, corresponding to quality-adjusted life year gains of 25.74 and 25.75. Compared with the current standard of care (SAS), USS produced higher average lifetime costs and lower quality of life for each sex. Deterministic and probabilistic sensitivity analyses showed that the model was robust to realistic changes in all the variables, making USS cost-ineffective on the basis of these outcomes.USS and SAS are similar in lifetime costs and quality of life, although the current SAS strategy was overall more cost-effective in preventing bone loss and fractures among patients with undiagnosed or subclinical disease. On the basis of best available supportive evidence, it is more cost-effective to maintain the standard celiac screening practices, although future robust population-based evidence in other health outcomes could be leveraged to reevaluate current screening guidelines.

    View details for DOI 10.1016/j.cgh.2012.12.037

    View details for Web of Science ID 000320306400014

    View details for PubMedID 23357490

  • Non-Drug Costs Associated with Outpatient Infliximab Administration in Pediatric Inflammatory Bowel Disease INFLAMMATORY BOWEL DISEASES Wu, M., Sin, A., Nishioka, F., Park, K. T. 2013; 19 (7): 1514-1517

    Abstract

    : Infliximab is the most widely used biological agent for Crohn's disease (CD) and ulcerative colitis (UC) but requires outpatient infusion units because of its intravenous administration requirement. The aim of this study was (1) to determine the average non-drug costs associated with each outpatient use of infliximab for pediatric inflammatory bowel disease and (2) to determine the proportion of non-drug costs associated with each outpatient infliximab use relative to the total cost of each encounter.: Hospital administrative and pharmacy databases were queried for all short stay unit encounters at Lucile Packard Children's Hospital at Stanford University linked to infliximab infusions for inflammatory bowel disease between January 1, 2006, and December 31, 2011. Infliximab drug and non-drug costs associated with CD and UC were compared.: A total of 771 unique encounters were generated for 76 pediatric patients (53 CD, 23 UC). For direct costs related to infliximab infusions for either CD or UC patients, more than 77% of the total health care costs per encounter were related to personnel (e.g., nursing), facility operations, and laboratory costs. Only 23% of the total costs were related to the actual infliximab drug costs. Based on an 80/20 payor mix of managed care versus government-subsidized insurance payers, 24.5% of the total reimbursements were applied to non-drug costs in CD and 20.9% in UC.: Non-drug costs represent a substantial proportion of the total cost of outpatient infliximab-related actual costs in inflammatory bowel disease. Personnel costs represent the largest segment of the non-drug costs. The actual drug costs of infliximab represent a small proportion of the total costs.

    View details for DOI 10.1097/MIB.0b013e318281f4f1

    View details for Web of Science ID 000329360800024

    View details for PubMedID 23567783

  • Geographical Rural Status and Health Outcomes in Pediatric Liver Transplantation: An Analysis of 6 Years of National United Network of Organ Sharing Data JOURNAL OF PEDIATRICS Park, K. T., Bensen, R., Lu, B., Nanda, P., Esquivel, C., Cox, K. 2013; 162 (2): 313-?

    Abstract

    To determine whether children in rural areas have worse health than children in urban areas after liver transplantation (LT).We used urban influence codes published by the US Department of Agriculture to categorize 3307 pediatric patients undergoing LT in the United Network of Organ Sharing database between 2004 and 2009 as urban or rural. Allograft rejection, patient death, and graft failure were used as primary outcome measures of post-LT health. Pediatric end-stage liver disease/model of end-stage liver disease scores >20 was used to measure worse pre-LT health.In a multivariate analysis, we found greater rates of allograft rejection within 6 months of LT (OR 1.27; 95% CI 1.05-1.53) and a lower occurrence of posttransplantation lymphoproliferative disorder (OR 0.64; 95% CI 0.41-0.99) in patients in rural areas. The difference in allograft rejection was eliminated at 1 year of LT (OR 1.18; 95% CI 0.98-1.42). Rural location did not impact other outcome measures.We conclude that rural location makes a negative impact on patient health within the first 6 months of LT by increasing the risk for allograft rejection, although patients in rural areas may have lower rates of developing posttransplantation lymphoproliferative disorder. Long-term adverse health effects were not seen.

    View details for DOI 10.1016/j.jpeds.2012.07.015

    View details for Web of Science ID 000313579900021

    View details for PubMedID 22914224

  • Impact of Immunosuppression on the Development of Epstein-Barr Virus (EBV) Viremia After Pediatric Liver Transplantation TRANSPLANTATION PROCEEDINGS Lu, B. R., Park, K. T., Hurwitz, M., Cox, K. L., Berquist, W. E. 2013; 45 (1): 301-304

    Abstract

    Pediatric liver transplant (OLT) patients are at risk of posttransplant lymphoproliferative disease (PTLD) from Epstein-Barr virus (EBV). This study examined the impact of induction and immunosuppression on EBV viremia.A retrospective chart review was performed on 197 pediatric patients and induction regimen, immunosuppression levels, and EBV viremia were documented for 1 year post-OLT. Logistic regression models determined associations between induction, immunosuppression, and EBV.Fifty six percent of patients developed EBV viremia. Incidence of EBV viremia was 73% with antithymocyte globulin (ATG), 63% with daclizumab, and 39% for neither, though the trend was not significant [ATG: odds ratio (OR) 0.19; 95% confidence interval (CI) 0.024-1.58; P = .125; daclizumab OR; 1.07; 95% CI 0.270-4.23; P = .925]. Tacrolimus immunosuppression levels were supratherapeutic 28.7% of the time; however, only supratherapeutic tacrolimus levels between 0 and 2 weeks increased EBV viremia at 2 to 4 weeks post-OLT (OR 1.80; 95% CI 1.10-2.94; P = .02). Three patients developed PTLD.The use of ATG and daclizumab induction likely does not play a role in the development of EBV viremia. Supratherapeutic tacrolimus levels 0 to 2 weeks post-OLT impact the development of EBV viremia at 2 to 4 weeks. The incidence of PTLD was low, suggesting better EBV and immunosuppression monitoring plays an important role in reducing PTLD.

    View details for DOI 10.1016/j.transproceed.2012.04.035

    View details for Web of Science ID 000315007200060

    View details for PubMedID 23267800

  • Clinical Applicability of the Incidence of Pediatric Peptic Ulcer Bleeding in the United States JOURNAL OF PEDIATRIC GASTROENTEROLOGY AND NUTRITION Park, K. T. 2012; 54 (6): 718-718

    View details for DOI 10.1097/MPG.0b013e318250a74d

    View details for Web of Science ID 000304115900003

    View details for PubMedID 22367340

  • Chylous Ascites After Laparoscopic Nissen Fundoplication DIGESTIVE DISEASES AND SCIENCES Park, K. T., Adikibi, B., MacKinlay, G. A., Gillett, P. M., Sylvester, K. G., Kerner, J. A. 2012; 57 (1): 28-31

    View details for DOI 10.1007/s10620-011-1808-6

    View details for Web of Science ID 000298968500005

    View details for PubMedID 21735080

  • Perspectives on Cost-effective Medicine and the Use of Cost-effectiveness Analyses JOURNAL OF PEDIATRIC GASTROENTEROLOGY AND NUTRITION Park, K. T. 2012; 54 (1): 2-3

    View details for DOI 10.1097/MPG.0b013e3182354d50

    View details for Web of Science ID 000298550800002

    View details for PubMedID 22197853

  • Cost-effectiveness Analysis of Adjunct VSL#3 Therapy Versus Standard Medical Therapy in Pediatric Ulcerative Colitis JOURNAL OF PEDIATRIC GASTROENTEROLOGY AND NUTRITION Park, K. T., Perez, F., Tsai, R., Honkanen, A., Bass, D., Garber, A. 2011; 53 (5): 489-496

    Abstract

    Inflammatory bowel diseases (IBDs) are costly chronic gastrointestinal diseases, with pediatric IBD representing increased costs per patient compared to adult disease. Health care expenditures for ulcerative colitis (UC) are >$2 billion annually. It is not clear whether the addition of VSL#3 to standard medical therapy in UC induction and maintenance of remission is a cost-effective strategy.We performed a systematic review of the literature and created a Markov model simulating a cohort of 10-year-old patients with severe UC, studying them until 100 years of age or death. We compared 2 strategies: standard medical therapy versus medical therapy + VSL#3. For both strategies, we assumed that patients progressed through escalating therapies--mesalamine, azathioprine, and infliximab--before receiving a colectomy + ileal pouch anal anastamosis (IPAA) if the 3 medical therapy options were exhausted. The primary outcome measure was the incremental cost-effectiveness ratio (ICER), defined as the difference of costs between strategies for each quality-adjusted life-year (QALY) gained. One-way sensitivity analyses were performed on variables to determine the key variables affecting cost-effectiveness.Standard medical care accrued a lifetime cost of $203,317 per patient, compared to $212,582 per patient for medical therapy + VSL#3. Lifetime QALYs gained was comparable for standard medical therapy and medical therapy + VSL#3 at 24.93 versus 25.05, respectively. Using the definition of ICER <50,000/QALY as a cost-effective intervention, medical therapy + VSL#3 produced an ICER of $79,910 per QALY gained, making this strategy cost-ineffective. Sensitivity analyses showed that 4 key parameters could affect the cost-effectiveness of the 2 strategies: cost of colectomy + IPAA, maintenance cost after surgery, probability of developing pouchitis after surgery, and the quality of life after a colectomy + IPAA. High surgical and postsurgical costs, a high probability of developing pouchitis, and a low quality of life after a colectomy + IPAA could make adjunct VSL#3 use a cost-effective strategy.Given present data, adjunct VSL#3 use for pediatric UC induction and maintenance of remission is not cost-effective, although several key parameters could make this strategy cost-effective. The quality of life after an IPAA is the single most important variable predicting whether this procedure benefits patients over escalating standard medical therapy.

    View details for DOI 10.1097/MPG.0b013e3182293a5e

    View details for Web of Science ID 000296383000007

    View details for PubMedID 21694634

  • RURALITY AND HEALTH OUTCOMES IN PEDIATRIC LIVER TRANSPLANTATION Park, K. T., Bensen, R., Nanda, P., Esquivel, C., Cox, K. WILEY-BLACKWELL. 2011: 135-135
  • Inflammatory Bowel Disease-Attributable Costs and Cost-effective Strategies in the United States: A Review INFLAMMATORY BOWEL DISEASES Park, K. T., Bass, D. 2011; 17 (7): 1603-1609

    Abstract

    The United States spends more for healthcare than any other country in the world. With the rising prevalence of both Crohn's disease and ulcerative colitis, inflammatory bowel disease (IBD) represents the leading chronic gastrointestinal disease with increasing healthcare expenditures in the US. IBD costs have shifted from inpatient to outpatient care since the introduction of biologic therapies as the standard of care. Gastroenterologists need to be aware of the national cost burden of IBD and clinical practices that optimize cost-efficiency. This investigation offers a systematic review of the economics of IBD and evidence-based strategies for cost-effective management.

    View details for DOI 10.1002/ibd.21488

    View details for Web of Science ID 000292415200017

    View details for PubMedID 21053357

  • Effects of rural status on health outcomes in pediatric liver transplantation: A single center analysis of 388 patients PEDIATRIC TRANSPLANTATION Park, K. T., Nanda, P., Bensen, R., Strichartz, D., Esquivel, C., Cox, K. 2011; 15 (3): 300-305

    Abstract

    Rural status of patients may impact health before and after pediatric LT. We used UI codes published by the USDA to stratify patients as urban or rural depending county residence. A total of 388 patients who had LT and who met criteria were included. Rejection, PTLD, and survival were used as primary outcome measures of post-LT health. UNOS Status 1 and PELD/MELD scores >20 were used as secondary outcome measures of poorer pre-LT health. Logistic regression models were run to determine associations. We did not find any statistically significant differences in pre- or post-LT outcomes with respect to rurality. Among rural patients, there was a general trend for decreased incidence of rejection (25.0% vs. 33.4%; OR 0.64, 95% CI 0.29-1.44), increased risk of PTLD (5.6% vs. 3.4%; OR 1.86, 95% CI 0.36-3.31), and decreased survival (OR 0.85, 95% CI 0.34-2.13) after LT. Rural patients also tended to be sicker at the time of LT than patients from urban areas, with increased proportion of Status 1 (OR 1.17, 95% CI 0.51-2.70) and PELD/MELD scores >20 (OR 1.20, 95% CI 0.59-2.45). From a single center experience, we conclude that rurality did not significantly affect health outcomes after LT, although a larger study may validate the general trends that rural patients may have decreased rejection, increased PTLD, and mortality, and be in poorer health at the time of LT.

    View details for DOI 10.1111/j.1399-3046.2010.01452.x

    View details for Web of Science ID 000289628100018

    View details for PubMedID 21450010

  • Aluminum in pediatric parenteral nutrition products: measured versus labeled content. The journal of pediatric pharmacology and therapeutics : JPPT : the official journal of PPAG Poole, R. L., Pieroni, K. P., Gaskari, S., Dixon, T. K., Park, K., Kerner, J. A. 2011; 16 (2): 92-97

    Abstract

    Aluminum is a contaminant in all parenteral nutrition solutions. Manufacturers currently label these products with the maximum aluminum content at the time of expiry, but there are no published data to establish the actual measured concentration of aluminum in parenteral nutrition solution products prior to being compounded in the clinical setting. This investigation assessed quantitative aluminum content of products commonly used in the formulation of parenteral nutrition solutions. The objective of this study is to determine the best products to be used when compounding parenteral nutrition solutions (i.e., those with the least amount of aluminum contamination).All products available in the United States from all manufacturers used in the production of parenteral nutrition solutions were identified and collected. Three lots were collected for each identified product. Samples were quantitatively analyzed by Mayo Laboratories. These measured concentrations were then compared to the manufacturers' labeled concentration.Large lot-to-lot and manufacturer-to-manufacturer differences were noted for all products. Measured aluminum concentrations were less than manufacturer-labeled values for all products.The actual aluminum concentrations of all the parenteral nutrition solutions were significantly less than the aluminum content based on manufacturers' labels. These findings indicate that 1) the manufacturers should label their products with actual aluminum content at the time of product release rather than at the time of expiry, 2) that there are manufacturers whose products provide significantly less aluminum contamination than others, and 3) pharmacists can select products with the lowest amounts of aluminum contamination and reduce the aluminum exposure in their patients.

    View details for DOI 10.5863/1551-6776-16.2.92

    View details for PubMedID 22477831

  • The use of Omegaven in treating parenteral nutrition-associated liver disease JOURNAL OF PERINATOLOGY Park, K. T., NESPOR, C., Kerner, J. 2011; 31: S57-S60

    Abstract

    Parenteral nutrition (PN), containing fat emulsions derived from soybean, has been implicated in the progression of PN-associated liver disease and cholestasis, particularly in infants with short bowel syndrome. Clinical use of Omegaven, a parenteral fish-oil emulsion, has been shown in recent studies to be a promising therapy to reverse liver disease and cholestasis. This review summarizes the rationale, relevant clinical investigations and future direction of Omegaven therapy for PN-dependent infants.

    View details for DOI 10.1038/jp.2010.182

    View details for Web of Science ID 000289236900009

    View details for PubMedID 21448206

  • Exfoliative Rejection in Intestinal Transplantation DIGESTIVE DISEASES AND SCIENCES Park, K. T., Berquist, W. L., Pai, R., Triadafilopoulos, G. 2010; 55 (12): 3336-3338

    View details for DOI 10.1007/s10620-010-1354-7

    View details for Web of Science ID 000284066200006

    View details for PubMedID 20683662