Jacob Bor

Increases in Adult Life Expectancy in Rural South Africa: Valuing the Scale-Up of HIV Treatment

Cost-Benefit of ART In the battle to control HIV, mass antiretroviral treatment (ART) costs

Regression discontinuity designs in epidemiology: causal inference without randomized trials.

500 to

In A Study Of A Population Cohort In South Africa, HIV Patients On Antiretrovirals Had Nearly Full Recovery Of Employment

900 per person per year. Bor et al. (p. 961) calculated the impact of intensifying ART on the life expectancy of people living in rural KwaZulu Natal. The dates of death were collected from a population of about 100,000 people during 2000–2011: Four years before and 8 years after the scaling up of ART. Life expectancy of adults increased by more than 11 years after ART was expanded, and the economic value of the lifetimes gained were calculated to far exceed the cost of treatment. Tanser et al. (p. 966) followed nearly 17,000 HIV-uninfected individuals in KwaZulu-Natal over an 8-year period. Holding other HIV risk factors constant, individual HIV acquisition risk declined significantly with increasing ART coverage of HIV-infected people. Adult life expectancy has increased by 11 years in rural KwaZulu-Natal since the 2004 public-sector scale-up of HIV treatment. The scale-up of antiretroviral therapy (ART) is expected to raise adult life expectancy in populations with high HIV prevalence. Using data from a population cohort of over 101,000 individuals in rural KwaZulu-Natal, South Africa, we measured changes in adult life expectancy for 2000–2011. In 2003, the year before ART became available in the public-sector health system, adult life expectancy was 49.2 years; by 2011, adult life expectancy had increased to 60.5 years—an 11.3-year gain. Based on standard monetary valuation of life, the survival benefits of ART far outweigh the costs of providing treatment in this community. These gains in adult life expectancy signify the social value of ART and have implications for the investment decisions of individuals, governments, and donors.

Correcting HIV prevalence estimates for survey nonparticipation using Heckman-type selection models.

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Alcohol Use During the Great Recession of 2008-2009

Antiretroviral therapy for HIV may have important economic benefits for patients and their households. We quantified the impact of HIV treatment on employment status among HIV patients in rural South Africa who were enrolled in a public-sector HIV treatment program supported by the Presidents Emergency Plan for AIDS Relief. We linked clinical data from more than 2,000 patients in the treatment program with ten years of longitudinal socioeconomic data from a complete community-based population cohort of more than 30,000 adults residing in the clinical catchment area. We estimated the employment effects of HIV treatment in fixed-effects regressions. Four years after the initiation of antiretroviral therapy, employment among HIV patients had recovered to about 90 percent of baseline rates observed in the same patients three to five years before they started treatment. Many patients initiated treatment early enough that they were able to avoid any loss of employment due to HIV. These results represent the first estimates of employment recovery among HIV patients in a general population, relative to the employment levels that these patients had prior to job-threatening HIV illness and the decision to seek care. There are large economic benefits to HIV treatment. For some patients, further gains could be obtained from initiating antiretroviral therapy earlier, prior to HIV-related job loss.

Mass HIV Treatment and Sex Disparities in Life Expectancy: Demographic Surveillance in Rural South Africa.

Background: HIV prevalence estimates from population-based surveys are vulnerable to selection bias if HIV status is missing for a proportion of the eligible population. Standard approaches, such as imputation, to correct prevalence estimates for selective nonparticipation assume that data are “missing at random.” These approaches lead to biased estimates, if unobserved factors are associated with both survey participation and HIV status. Methods: We use Heckman-type selection models to test and correct for selection on unobserved factors (separately for men and women) in the 2007 Zambia Demographic and Health Survey, in which 28% of the 7146 eligible men and 23% of the 7408 eligible women did not participate in HIV testing. Performance of these models depends crucially on selection variables that determine survey participation but do not independently affect HIV status. Results: We identify 2 highly-plausible selection variables that are statistically significant determinants of survey participation: interviewer identity, and visit on the first day of fieldwork in a survey cluster. HIV-positive status was negatively correlated with consent to test in men (&rgr; = −0.75 [95% confidence interval = −0.94 to −0.18]), but not in women. Adjusting for selection on unobserved variables substantially increased the HIV prevalence estimate for men from 12% (based on measured HIV status alone) and 12% (based on imputation) to 21%. In addition, the adjustment for selection substantially changed the estimated effects of HIV risk factors. Conclusions: Studies of HIV prevalence and risk factors based on surveys with substantial nonparticipation should routinely use Heckman-type selection models to correct for selection on unobserved variables.

Differential impact of the economic recession on alcohol use among white British adults, 2004–2010

AIMS The aim of this study was to assess changes in alcohol use in the USA during the Great Recession. METHODS Drinking participation, drinking frequency, drinking intensity, total alcohol consumption and frequency of binge drinking were assessed in a nationally representative sample of 2,050,431 US women and men aged 18 and older, interviewed between 2006 and 2010. RESULTS The prevalence of any alcohol use significantly declined during the economic recession, from 52.0% in 2006-2007 to 51.6% in 2008-2009 (P < 0.05), corresponding to 880,000 fewer drinkers (95% confidence interval [CI] 140,000 to 1.6 million). There was an increase, however, in the prevalence of frequent binging, from 4.8% in 2006-2007 to 5.1% in 2008-2009 (P < 0.01), corresponding to 770,000 more frequent bingers (95% CI 390,000 to 1.1 million). Non-Black, unmarried men under 30 years, who recently became unemployed, were at highest risk for frequent binging. CONCLUSION During the Great Recession there was an increase in abstention from alcohol and a rise in frequent binging.

Length of secondary schooling and risk of HIV infection in Botswana: evidence from a natural experiment

Background Women have better patient outcomes in HIV care and treatment than men in sub-Saharan Africa. We assessed—at the population level—whether and to what extent mass HIV treatment is associated with changes in sex disparities in adult life expectancy, a summary metric of survival capturing mortality across the full cascade of HIV care. We also determined sex-specific trends in HIV mortality and the distribution of HIV-related deaths in men and women prior to and at each stage of the clinical cascade. Methods and Findings Data were collected on all deaths occurring from 2001 to 2011 in a large population-based surveillance cohort (52,964 women and 45,688 men, ages 15 y and older) in rural KwaZulu-Natal, South Africa. Cause of death was ascertained by verbal autopsy (93% response rate). Demographic data were linked at the individual level to clinical records from the public sector HIV treatment and care program that serves the region. Annual rates of HIV-related mortality were assessed for men and women separately, and female-to-male rate ratios were estimated in exponential hazard models. Sex-specific trends in adult life expectancy and HIV-cause-deleted adult life expectancy were calculated. The proportions of HIV deaths that accrued to men and women at different stages in the HIV cascade of care were estimated annually. Following the beginning of HIV treatment scale-up in 2004, HIV mortality declined among both men and women. Female adult life expectancy increased from 51.3 y (95% CI 49.7, 52.8) in 2003 to 64.5 y (95% CI 62.7, 66.4) in 2011, a gain of 13.2 y. Male adult life expectancy increased from 46.9 y (95% CI 45.6, 48.2) in 2003 to 55.9 y (95% CI 54.3, 57.5) in 2011, a gain of 9.0 y. The gap between female and male adult life expectancy doubled, from 4.4 y in 2003 to 8.6 y in 2011, a difference of 4.3 y (95% CI 0.9, 7.6). For women, HIV mortality declined from 1.60 deaths per 100 person-years (95% CI 1.46, 1.75) in 2003 to 0.56 per 100 person-years (95% CI 0.48, 0.65) in 2011. For men, HIV-related mortality declined from 1.71 per 100 person-years (95% CI 1.55, 1.88) to 0.76 per 100 person-years (95% CI 0.67, 0.87) in the same period. The female-to-male rate ratio for HIV mortality declined from 0.93 (95% CI 0.82–1.07) in 2003 to 0.73 (95% CI 0.60–0.89) in 2011, a statistically significant decline (p = 0.046). In 2011, 57% and 41% of HIV-related deaths occurred among men and women, respectively, who had never sought care for HIV in spite of the widespread availability of free HIV treatment. The results presented here come from a poor rural setting in southern Africa with high HIV prevalence and high HIV treatment coverage; broader generalizability is unknown. Additionally, factors other than HIV treatment scale-up may have influenced population mortality trends. Conclusions Mass HIV treatment has been accompanied by faster declines in HIV mortality among women than men and a growing female–male disparity in adult life expectancy at the population level. In 2011, over half of male HIV deaths occurred in men who had never sought clinical HIV care. Interventions to increase HIV testing and linkage to care among men are urgently needed.

Population health in an era of rising income inequality: USA, 1980–2015

BACKGROUND Unlike other west European countries, there is a long-term trend of rising alcohol consumption and mortality in England. Whether drinking will rise or fall during the current recession is widely debated. We examined how the recession affected alcohol use in adults in England using individual-level data. METHODS We analysed a nationally representative sample of non-institutionalized white persons aged 20-60 years from seven waves of the Health Survey for England, 2004-2010 (n = 36 525), to assess trends in alcohol use and frequency before, during and after the recession and in association with unemployment, correcting for possible changes in sample composition and socio-demographic confounders. The primary analysis compared 2006/7 with 2008/9, following the official onset of the UK recession in early 2008. RESULTS During Englands recession, there was a significant decrease in frequent drinking defined as drinking four or more days in the past week (27.1% in 2006 to 23.9% in 2009, P < 0.001), the number of units of alcohol imbibed on the heaviest drinking day (P < 0.01) and the number of days that individuals reported drinking over the past seven days (P < 0.01). However, among current drinkers who were unemployed there was a significantly elevated risk of binge drinking in 2009 and 2010 (odds ratio = 1.64, 95% confidence interval: 1.22-2.19, P = 0.001) that was not previously observed in 2004-2008 (1.03, 0.76-1.41; test for effect heterogeneity: P = 0.036). CONCLUSIONS Englands recession was associated with less hazardous drinking among the population overall, but with rises in binge drinking among a smaller high-risk group of unemployed drinkers.

Social exposure to an antiretroviral treatment programme in rural KwaZulu-Natal

Background An estimated 2·3 Million individuals are newly infected with HIV each year. Existing cross-sectional and longitudinal studies have found conflicting evidence on the association between education and HIV risk, and no randomized experiment to date has identified a causal effect of education on HIV incidence. Methods A 1996 policy reform changed the grade structure of secondary school in Botswana and increased educational attainment. We use this reform as a ‘natural experiment’ to identify the causal effect of schooling on HIV infection. Data on HIV biomarkers and demographics were obtained from the 2004 and 2008 Botswana AIDS Impact Surveys, nationally-representative household surveys (N = 7018). The association between years of schooling and HIV status was described using multivariate OLS regression models. Using exposure to the policy reform as an instrumental variable, we estimated the causal effect of years of schooling on the cumulative probability that an individual contracted HIV up to his or her age at the time of the survey. The cost-effectiveness of secondary schooling as an HIV prevention intervention was assessed in comparison to other established interventions. Findings Each additional year of secondary schooling induced by the policy change led to an absolute reduction in the cumulative risk of HIV infection of 8·1% points (p = 0·008), relative to a baseline prevalence of 25·6%. Effects were particularly large among women (11·6% points, p = 0·046). Results were robust to a wide array of sensitivity analyses. Secondary school was cost-effective as an HIV prevention intervention by standard metrics. Interpretation Additional years of secondary schooling had a large protective effect against HIV risk, particularly for women, in Botswana. Increasing progression through secondary school may be a cost-effective HIV prevention measure in HIV-endemic settings, in addition to yielding other societal benefits. Funding Takemi Program in International Health at the Harvard School of Public Health, Belgian American Educational Foundation, and Fernand Lazard Foundation.