Atheendar S. Venkataramani

Early life exposure to malaria and cognition in adulthood: Evidence from Mexico

This study examines the impact of early life malaria exposure on cognition in sample of Mexican adults, using the nationwide introduction of malaria eradication efforts to identify causal impacts. The core findings are that birth year exposure to malaria eradication was associated with increases in Raven Progressive Matrices test scores and consumption expenditures, but not schooling. Additionally, cohorts born after eradication both entered and exited school earlier than their pre-eradication counterparts. These effects were only seen for men and explanations for this are assessed. Collectively, these findings suggest that improvements in infant health help explain secular increases in cognitive test scores, that better cognition may link early life health to adulthood earnings, and that human capital investments through childhood and young adulthood respond sensitively to market returns to early life endowment shocks.

Measuring concurrent partnerships: potential for underestimation in UNAIDS recommended method.

Research on concurrent sexual partnerships has been constrained by inconsistent and inaccurate measurements of these partnerships. Recently, a UNAIDS working group recommended a method based on sexual partner histories to improve the measurement of concurrency. Using recent survey data for young adults living in Cape Town, South Africa, we found that this method could result in underestimates of concurrency due to respondents’ failure to report additional sexual partners.

Learning that Circumcision is Protective Against HIV: Risk Compensation Among Men and Women in Cape Town, South Africa

Objectives We examined whether knowledge of the HIV-protective benefits of male circumcision (MC) led to risk compensating behavior in a traditionally circumcising population in South Africa. We extend the current literature by examining risk compensation among women, which has hitherto been unexplored. Methods We used data on Xhosa men and women from the 2009 Cape Area Panel Study. Respondents were asked if they had heard that MC reduces a man’s risk of contracting HIV, about their perceived risk of contracting HIV, and condom use. For each gender group we assessed whether risk perception and condom use differed by knowledge of the protective benefits of MC using bivariate and then multivariate models controlling for demographic characteristics, HIV knowledge/beliefs, and previous sexual behaviors. In a further check for confounding, we used data from the 2005 wave to assess whether individuals who would eventually become informed about the protective benefits of circumcision were already different in terms of HIV risk perception and condom use. Results 34% of men (n = 453) and 27% of women (n = 690) had heard that circumcision reduces a man’s risk of HIV infection. Informed men perceived slightly higher risk of contracting HIV and were more likely to use condoms at last sex (p<0.10). Informed women perceived lower HIV risk (p<0.05), were less likely to use condoms both at last sex (p<0.10) and more generally (p<0.01), and more likely to forego condoms with partners of positive or unknown serostatus (p<0.01). The results were robust to covariate adjustment, excluding people living with HIV, and accounting for risk perceptions and condom use in 2005. Conclusions We find evidence consistent with risk compensation among women but not men. Further attention should be paid to the role of new information regarding MC, and drivers of HIV risk more broadly, in modulating sexual behavior among women.

A cut above the rest: traditional male circumcision and HIV risk among Xhosa men in Cape Town South Africa.

BackgroundRandomized clinical trials have shown that medical male circumcision substantially reduces the risk of contracting HIV. However, relatively little is known about the relationship between traditional male circumcision and HIV risk. This article examines variations in traditional circumcision practices and their relationship to HIV status. MethodsWe used data from the fifth wave of the Cape Area Panel Study (n = 473) of young adults in Cape Town, South Africa, to determine attitudes towards circumcision, whether men were circumcised, at what age, and whether their foreskin had been fully or partially removed. Probit models were estimated to determine the association between extent and age of circumcision and HIV status. ResultsThere was strong support for traditional male circumcision. 92.5% of the men reported being circumcised, with 10.5% partially circumcised. Partially circumcised men had a 7% point greater risk of being HIV positive than fully circumcised men (P < 0.05) and equal risk compared with uncircumcised men. Most (91%) men were circumcised between the ages of 17 and 22 years (mean 19.2 years), and HIV risk increased with age of circumcision (P < 0.10). ConclusionsEfforts should be made to encourage earlier circumcisions and to work with traditional surgeons to reduce the number of partial circumcisions. Data on the extent and age of circumcision are necessary for meaningful conclusions to be drawn from survey data about the relationship between circumcision and HIV status.

The Impact of Tax Policies on Living Organ Donations in the United States

In an effort to increase living organ donation, fifteen states passed tax deductions and one a tax credit to help defray potential medical, lodging and wage loss costs between 2004 and 2008. To assess the impact of these policies on living donation rates, we used a differences‐in‐differences strategy that compares the pre‐ and postlegislation change in living donations in states that passed legislation against the same change in those states that did not. We found no statistically significant effect of these tax policies on donation rates. Furthermore, we found no evidence of any lagged effects, differential impacts by gender, race or donor relationship, or impacts on deceased donation. Possible hypotheses to explain our findings are: the cash value of the tax deduction may be too low to defray costs faced by donors, lack of public awareness about the existence of these policies, and that states that were proactive enough to pass tax policy laws may have already depleted donor pools with previous interventions.

Shadows of the Captain of the Men of Death: Early Life Health Interventions, Human Capital Investments, and Institutions

We leverage introduction of the first antibiotic therapies in 1937 to examine impacts of pneumonia in infancy on adult education, employment, disability, income and income mobility, and identify large impacts on each. We then examine how racial segregation in the pre-Civil Rights Era moderated the long-run benefits of antibiotics among blacks. We find that blacks born in more segregated states reaped smaller and less pervasive long run benefits despite sharp drops in pneumonia exposure. Our findings demonstrate causal effects of early life health on economic mobility and the importance of an investment-rewarding institutional environment in realization of the full potential of a healthy start.We exploit the introduction of sulfa drugs in 1937 to identify the causal impact of exposure to pneumonia in infancy on later life well-being and productivity in the United States. Using census data from 1980-2000, we find that cohorts born after the introduction of sulfa experienced increases in schooling, income, and the probability of employment, and reductions in disability rates. These improvements were larger for those born in states with higher pre-intervention levels of pneumonia as these were the areas that benefited most from the availability of sulfa drugs. These estimates are, in general, larger and more robust to specification for men than for women. With the exception of cognitive disability and poverty for men, the estimates for African Americans are smaller and less precisely estimated than those for whites. This is despite our finding that African Americans experienced larger absolute reductions in pneumonia mortality after the arrival of sulfa. We suggest that pre-Civil Rights barriers may have inhibited their translating improved endowments into gains in education and employment.

CD4+ cell count at antiretroviral therapy initiation and economic restoration in rural Uganda.

Objective:To determine whether earlier initiation of antiretroviral therapy (ART) is associated with better economic outcomes. Design:Prospective cohort study of HIV-positive patients on ART in rural Uganda. Methods:Patients initiating ART at a regional referral clinic in Uganda were enrolled in the Uganda AIDS Rural Treatment Outcomes study starting in 2005. Data on labor force participation and asset ownership were collected on a yearly basis, and CD4+ cell counts were collected at pre-ART baseline. We fitted multivariable regression models to assess whether economic outcomes at baseline and in the 6 years following ART initiation varied by baseline CD4+ cell count. Results:Five hundred and five individuals, followed up to 6 years, formed the estimation sample. Participants initiating ART at CD4+ cell count at least 200 cells/&mgr;l were 13 percentage points more likely to be working at baseline (P < 0.01, 95% confidence interval 0.06–0.21) than those initiating below this threshold. Those in the latter group achieved similar labor force participation rates within 1 year of initiating ART (P < 0.01 on the time indicators). Both groups had similar asset scores at baseline and demonstrated similar increases in asset scores over the 6 years of follow-up. Conclusion:ART helps participants initiating therapy at CD4+ cell count below 200 cells/&mgr;l rejoin the labor force, though the findings for participants initiating with higher CD4+ cell counts suggests that pretreatment declines in labor supply may be prevented altogether with earlier therapy. Baseline similarities in asset scores for those with early and advanced disease suggest that mechanisms other than morbidity may help drive the relationship between HIV infection and economic outcomes.

The intergenerational transmission of height: evidence from rural Vietnam

A growing body of work suggests that health may be transferred across generations. The aim of this paper is to examine the mechanisms that might account for observed intergenerational associations in health outcomes. Using data from Vietnam, this study analyzes intergenerational correlations in height, a measure of long-run health status, between parents and their children. Insights from biology and economics are used to motivate several strategies that collectively provide insight on the role and importance of different mechanisms. The results illustrate strong intergenerational associations in height, which remain stable with the inclusion of controls for parent and household characteristics. Maternal height is more strongly associated with the heights of boys than girls, while the associations with paternal height are similar across genders. The use of conditions faced by parents early in life as instruments for their height yields significantly larger estimates of the mother-child height association relative to OLS, while the estimated father-child associations move to zero. These results, in conjunction with those from several other tests, illustrate that non-genetic factors are important in determining parent-child associations in height, and more speculatively, that epigenetic mechanisms may play an important role. These findings illustrate the value of investments in early childhood, as these may confer intergenerational benefits.

Social Grants, Welfare, and the Incentive to Trade-Off Health for Income among Individuals on HAART in South Africa

South Africa’s government disability grants are considered important in providing income support to low-income AIDS patients. Indeed, anecdotal evidence suggests that some individuals may opt to compromise their health by foregoing Highly Active Antiretroviral Treatment (HAART) to remain eligible for the grant. In this study, we examined the disability grant’s importance to individual and household welfare, and the impact of its loss using a unique longitudinal dataset of HAART patients in Khayelitsha, Cape Town. We found that grant loss was associated with sizeable declines in income and changes in household composition. However, we found no evidence of individuals choosing poor health over grant loss. Our analysis also suggested that though the grants officially target those too sick to work, some people were able to keep grants longer than expected, and others received grants while employed. This has helped cushion people on HAART, but other welfare measures need consideration.

Regression discontinuity designs in healthcare research

Clinical decisions are often driven by decision rules premised around specific thresholds. Specific laboratory measurements, dates, or policy eligibility criteria create cut-offs at which people become eligible for certain treatments or health services. The regression discontinuity design is a statistical approach that utilizes threshold based decision making to derive compelling causal estimates of different interventions. In this review, we argue that regression discontinuity is underutilized in healthcare research despite the ubiquity of threshold based decision making as well as the design’s simplicity and transparency. Moreover, regression discontinuity provides evidence of “real world” therapeutic and policy effects, circumventing a major limitation of randomized controlled trials. We discuss the implementation, strengths, and weaknesses of regression discontinuity and review several examples from clinical medicine, public health, and health policy. We conclude by discussing the wide array of open research questions for which regression discontinuity stands to provide meaningful insights to clinicians and policymakers