TRA-2-1 CAPTURING THE HEALTH AND ECONOMIC EFFECTS OF TUBERCULOSIS IN INDIA VIA DYNAMIC MICROSIMULATION MODEL CALIBRATION AND VALIDATION

Monday, October 24, 2016: 10:00 AM
Bayshore Ballroom Salon F, Lobby Level (Westin Bayshore Vancouver)

Jeremy D. Goldhaber-Fiebert, PhD1, David Stauffer, MS1, Lea Prince, PhD1, Jason Andrews, MD, MS2, Sanjay Basu, MD, PhD1, Marcella Alsan, MD, PhD1, Eran Bendavid, MD, MS3, Margaret L. Brandeau, PhD4 and Douglas K. Owens, MD, MS5, (1)Stanford University, Stanford, CA, (2)Stanford University School of Medicine, Stanford, CA, (3)Division of General Medical Disciplines, Department of Medicine, Stanford University, Stanford, CA, (4)Department of Management Science and Engineering, Stanford University, Stanford, CA, (5)VA Palo Alto Health Care System, Palo Alto, CA

Purpose: Despite India's rapid economic development, it still has the world's largest number of active tuberculosis (TB) cases and hundreds of millions of people living in poverty. Assessments of TB control programs have primarily focused on health gains; yet, returns to such programs may be underestimated without also considering the relationship between TB and impoverishment. We developed, calibrated, and validated a model to consider the health and economic effects of TB in India.

Methods: We extended our prior dynamic transmission microsimulation of TB in India, stratifying it by socioeconomic status (SES), represented as real per-capita consumption expenditure. We parameterized SES in the model using the Indian National Sample Survey (1994-2012; n=5,548,989). The model captures relevant dynamics including: 1) secular economic growth (average improvement in real per-capita consumption expenditure over time) and shifts in the SES distribution; 2) TB transmission dynamics within and between members of SES groups; and 3) SES-specific risks of latent TB activation. We calibrated the model to overall demographic trends; WHO-reported TB trends (1996-2013); and age-, urban/rural- and SES-specific TB prevalence estimates from India's National Family and Health Survey-3 (NFHS-3). We validate the longer term impact of TB on SES using longitudinal data from the Indian Human Development Survey (IHDS) (2004/2005, 2011/2012; n=215,754).

Results: In addition to overall demographic trends, the model calibrates well to TB prevalence trends, and SES-specific TB prevalence in multiple subpopulations (Figure 1, Panels A-C). Figure 1 shows that while overall TB prevalence has declined, among the poorest group, it remains 2.5 times higher than in the wealthiest. While TB prevalence is generally higher in older ages, among the poorest of any age group, it is >3 times higher than similarly aged wealthy individuals. The model validates against longitudinal impacts of TB on SES. For example, both the model and IHDS data show that for individuals in the wealthiest SES groups, having TB in 2004 nearly doubles the chance of being in the poor SES group in 2011.

Conclusions: Our dynamic microsimulation captures relationships between TB and SES in India and strongly suggests that TB control could deliver substantial economic value beyond its direct health effects, an important consideration for future model-based economic evaluations of such programs.