Clinical Focus

  • Family Medicine

Academic Appointments

Professional Education

  • Medical Education:Univ of California San Francisco (2010) CA
  • Board Certification: Family Medicine, American Board of Family Medicine (2013)
  • Residency:Contra Costa Regional Medical Center (2013) CA
  • M.S., University of California Berkeley, Health and Medical Sciences (2008)
  • M.P.H., University of California Berkeley, Interdisciplinary Studies (2007)
  • A.B., Harvard University, Chemistry (2003)

Research & Scholarship

Current Research and Scholarly Interests

My research investigates the pathways linking poverty and health disparities. In particular, I study the impact on health outcomes of social and economic factors using interdisciplinary causal inference methods. I am interested in the mechanisms through which adverse socioeconomic conditions get "under the skin" to cause health disparities.


Journal Articles

  • Large-scale automated analysis of news media: A novel computational method for obesity policy research. Obesity Hamad, R., Pomeranz, J. L., Siddiqi, A., Basu, S. 2015; 23 (2): 296-300


    Analyzing news media allows obesity policy researchers to understand popular conceptions about obesity, which is important for targeting health education and policies. A persistent dilemma is that investigators have to read and manually classify thousands of individual news articles to identify how obesity and obesity-related policy proposals may be described to the public in the media. A machine learning method called "automated content analysis" that permits researchers to train computers to "read" and classify massive volumes of documents was demonstrated.14,302 newspaper articles that mentioned the word "obesity" during 2011-2012 were identified. Four states that vary in obesity prevalence and policy (Alabama, California, New Jersey, and North Carolina) were examined. The reliability of an automated program to categorize the media's framing of obesity as an individual-level problem (e.g., diet) and/or an environmental-level problem (e.g., obesogenic environment) was tested.The automated program performed similarly to human coders. The proportion of articles with individual-level framing (27.7-31.0%) was higher than the proportion with neutral (18.0-22.1%) or environmental-level framing (16.0-16.4%) across all states and over the entire study period (P < 0.05).A novel approach to the study of how obesity concepts are communicated and propagated in news media was demonstrated.

    View details for DOI 10.1002/oby.20955

    View details for PubMedID 25522013

  • Psychological well-being during the great recession: changes in mental health care utilization in an occupational cohort. American journal of public health Modrek, S., Hamad, R., Cullen, M. R. 2015; 105 (2): 304-310


    Objectives. We examined the mental health effects of the Great Recession of 2008 to 2009 on workers who remained continuously employed and insured. Methods. We examined utilization trends for mental health services and medications during 2007 to 2012 among a panel of workers in the 25 largest plants, located in 15 states, of a US manufacturing firm. We used piecewise regression to compare trends from 2007 to 2010 in service and medication use before and after 2009, the year of mass layoffs at the firm and the peak of the recession. Our models accounted for changes in county-level unemployment rates and individual-level fixed effects. Results. Mental health inpatient and outpatient visits and the yearly supply of mental health-related medications increased among all workers after 2009. The magnitude of the increase in medication usage was higher for workers at plants with more layoffs. Conclusions. The negative effects of the recession on mental health extend to employed individuals, a group considered at lower risk of psychological distress.

    View details for DOI 10.2105/AJPH.2014.302219

    View details for PubMedID 25521885

  • Microcredit participation and child health: results from a cross-sectional study in Peru JOURNAL OF EPIDEMIOLOGY AND COMMUNITY HEALTH Moseson, H., Hamad, R., FERNALD, L. 2014; 68 (12): 1175-1181
  • Microcredit participation and nutrition outcomes among women in Peru JOURNAL OF EPIDEMIOLOGY AND COMMUNITY HEALTH Hamad, R., Fernald, L. C. 2012; 66 (6)


    Microcredit services--the awarding of small loans to individuals who are too poor to take advantage of traditional financial services--are an increasingly popular scheme for poverty alleviation. Several studies have examined the ability of microcredit programmes to influence the financial standing of borrowers, but only a few studies have examined whether the added household income improves health and nutritional outcomes among household members. This study examined the hypothesis that longer participation in microcredit services would be associated with better nutritional status in women.Cross-sectional data were obtained in February 2007 from 1593 female clients of a microcredit organisation in Peru. The primary predictor variable was length of time as a microcredit client measured in number of completed loan cycles (range 0 to 5.5 years, average loan size US$350). The outcome variables were age-adjusted body mass index (BMI), haemoglobin levels (g/dl) and food insecurity measured using the US household food security survey module. Extensive data on demographic and socioeconomic status were also collected.Longer microcredit participation was associated with higher BMI (β=0.05, p=0.06), higher haemoglobin levels (β=0.07, p<0.01) and lower food insecurity (β=-0.13, p<0.01). With the inclusion of demographic and socioeconomic variables, the associations with higher haemoglobin (β=0.03, p=0.04) and lower food insecurity (β=-0.08, p<0.01) were sustained.This study supports the notion that microcredit participation has positive effects on the nutritional status of female clients. Further research should explore more definitive causal pathways through which these effects may occur and should examine the effects on other household members.

    View details for DOI 10.1136/jech.2010.108399

    View details for Web of Science ID 000303608800001

    View details for PubMedID 21051776

  • Health education for microcredit clients in Peru: a randomized controlled trial. BMC PUBLIC HEALTH Hamad, R., Fernald, L. C., Karlan, D. S. 2011; 11 (1): 51

    View details for DOI 10.1186/1471-2458-11-51

  • Small individual loans and mental health: a randomized controlled trial among South African adults BMC PUBLIC HEALTH Fernald, L. C., Hamad, R., Karlan, D., Ozer, E. J., Zinman, J. 2008; 8


    In the developing world, access to small, individual loans has been variously hailed as a poverty-alleviation tool - in the context of "microcredit" - but has also been criticized as "usury" and harmful to vulnerable borrowers. Prior studies have assessed effects of access to credit on traditional economic outcomes for poor borrowers, but effects on mental health have been largely ignored.Applicants who had previously been rejected (n = 257) for a loan (200% annual percentage rate - APR) from a lender in South Africa were randomly assigned to a "second-look" that encouraged loan officers to approve their applications. This randomized encouragement resulted in 53% of applicants receiving a loan they otherwise would not have received. All subjects were assessed 6-12 months later with questions about demographics, socio-economic status, and two indicators of mental health: the Center for Epidemiologic Studies - Depression Scale (CES-D) and Cohen's Perceived Stress scale. Intent-to-treat analyses were calculated using multinomial probit regressions.Randomization into receiving a "second look" for access to credit increased perceived stress in the combined sample of women and men; the findings were stronger among men. Credit access was associated with reduced depressive symptoms in men, but not women.Our findings suggest that a mechanism used to reduce the economic stress of extremely poor individuals can have mixed effects on their experiences of psychological stress and depressive symptomatology. Our data support the notion that mental health should be included as a measure of success (or failure) when examining potential tools for poverty alleviation. Further longitudinal research is needed in South Africa and other settings to understand how borrowing at high interest rates affects gender roles and daily life activities. CCT: ISRCTN 10734925.

    View details for DOI 10.1186/1471-2458-8-409

    View details for Web of Science ID 000264286900001

    View details for PubMedID 19087316

  • Social and economic correlates of depressive symptoms and perceived stress in South African adults JOURNAL OF EPIDEMIOLOGY AND COMMUNITY HEALTH Hamad, R., Fernald, L. C., Karlan, D. S., Zinman, J. 2008; 62 (6): 538-544


    Adults in South Africa demonstrate rates of mental illness at or above levels elsewhere in the developing world. Yet there is a research gap regarding the social context surrounding mental health in this region. The objective of this analysis was to characterize the prevalence and correlates of depressive symptoms and perceived stress among a heterogeneous South African population.Low-income adults (n = 257) in Capetown, Port Elizabeth and Durban were interviewed regarding demographics, income, subjective social status, life events and decision-making. The Center for Epidemiologic Studies Depression Scale (CES-D) and Cohen's Perceived Stress Scale (PSS) were used.CES-D scores were 18.8 (SD 11.7), with 50.4% of men and 64.5% of women exceeding the cut-off at which professional care is recommended (p = 0.03). PSS scores were 18.6 (SD 6.7), with a mean of 17.5 among men and 19.6 among women (p = 0.02). In multivariate regressions, increased CES-D scores were associated with more household members (p<0.1), lower educational attainment (p = 0.07), less income stability (p<0.07), lower subjective social status (p<0.01) and independent decision-making (p = 0.04). Increased PSS scores were associated with female gender (p<0.05), multiracial race (p<0.02), more household members (p<0.1), lower subjective social status (p<0.02) and recent birth or catastrophe (p<0.01).Depressive symptoms and perceived stress are public health concerns in this sample, with more symptoms among those with fewer resources. The prevention of mental illness is critical, especially in vulnerable populations.

    View details for DOI 10.1136/jech.2007.066191

    View details for Web of Science ID 000255805200012

    View details for PubMedID 18477753

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