Anti-Hypertensive Drug Demand in Latin America William H. Dow University of California, Berkeley January 2009

What Do We Know About Drug Use Rates? Latin America has ~8% of world pharmaceutical market Child vaccines: >75% of world children receive, but requires major campaigns. Hib vaccine: Slow to disseminate to LDCs. Deworming drugs: Cheap, but low use rates. Antibiotics: Widely used, misused.

Hypertension Drugs Little publicity, no quick benefit. Hypertension prevalence > 50%, leading cause of death. Drugs effective if used properly. 1/3 U.S. adults over 50 use. Cheap generics available for most classes.

Key Questions Comparative: What are hypertension drug use rates in Latin America? Do rates vary by country attributes (Cuba vs. Mexico)? Disparities: How big are disparities in drug use rates by education, wealth, urbanicity? Policy: Does insurance improve hypertension awareness, drug use rates, and hypertension control? –U.S.: Significant effects in RAND HIE and Medicaid populations. –Evidence base in middle-income countries is weak. Bleich et al. find compelling associations with Mexico’s Seguro Popular expansion, but call for further research with stronger causal designs.

SABE data PAHO multicenter study of Health, Well-Being and Aging in Latin America and the Caribbean (SABE). Standardized in 7 countries: Argentina, Barbados, Brazil, Chile, Cuba, Mexico, and Uruguay. Sample frame: Ages 60+, urban only. Self-reported hypertension and drug use (verified by medicine cabinet), and measured blood pressure. Has a doctor ever told you that you have high blood pressure or hypertension? If yes: Are you now taking any medication to lower your blood pressure?

Dependent Variables Self-reports: DV1. Current use of hypertensive drugs. DV2. Self-report of hypertension diagnosis. DV3. Use of drugs, conditional on diagnosis (from DV2). Objective: DV4. Measured high blood pressure (average of two readings above 140 diastolic or 90 systolic). DV5. Hypertension prevalence (current drug use from DV1, or measured high blood pressure from DV4). DV6. Unawareness (doctor never told hypertensive, from DV2), conditional on being hypertensive (from DV5).

SABE Explanatory Variables Health insurance (public). Education: None, some primary, completed primary, higher. Wealth: first principal component of household assets/characteristics. DV = f(insurance, education, wealth, male, age, urban) Linear probability models, Huber s.e.

Costa Rican CRELES Data Nationally representative survey in 2005 of 2,800 Costa Ricans ages 60+. –2005 data may be slightly higher drug use from secular trends, but not by much. –Only use urban sample for this paper. Drug utilization measured from “medicine cabinet” (may bias up or down). –Modify drug coding to exclude drugs from anti-hypertensive definition if person did not self-report a hypertension diagnosis.

United States NHANES Data, Nationally representative, with objective measures. –Use only ages 60+ –Use both urban and rural Higher power from larger sample. –Education coded only as HS

Mexican Health and Aging Study (MHAS) Data Nationally representative ages 50+, both urban and rural. Higher power from larger sample. Did not measure blood pressure. Did collect employment history, useful for IV.

Insurance Endogenous? Health insurance is employment based (current or retired self, spouse, kids). Adverse selection if respondent, spouse or child chooses job with insurance after diagnosed with chronic disease. => overstate insurance effects on awareness, drug use, and understate health benefits of insurance. OR positive selection if employers select on healthier individuals. => understate insurance effects on drug use, overstate health benefits. 2SLS: Instrument insurance with job characteristics of self and spouse, using “primary lifetime job”: occupation, employer type, worksite. –Corrects bias from late life switches, child job choice. –Assumes job chosen before ill. –IV may fail if uninsured jobs are more stressful. Can test by estimating insurance effect on prevalence (current or ever diagnosed, in ENSA data): effect should be small if IV is OK.

Summary Hypertension drug use remarkably high in Latin America, despite little publicity and no quick benefit. Drug use rates similar across countries, and across SES within countries: even 30% of uneducated poor. –Costa Rica curiously has largest urban education differentials of any country. –In Mexico, education gradients larger in rural areas. Insurance has big effects on drug use, increasing it 11 percentage points (on mean of 29%). Health benefits of insurance are less clear: awareness is higher, but no effect on current measured hypertension control in Mexican SABE. Useful to expand analysis to other diseases.