The Impact of a Community Health Worker Program on Childhood Immunization : Evidence from India's 'ASHA' Workers

In 2005-06 the Indian government introduced a new cadre of Community Health Workers known as Accredited Social Health Activists or ASHA workers to improve basic health outcomes through community engagement. The initial roll-out of the program, between 2005 and 2009, was heavily focused on 18 "high focus Indian states", lagging behind on public health indicators. Using multiple rounds of data from the District Level Household & Facility Survey (DLHS), I create cohorts of 12-23 month old infants, spanning a period of ten years, to establish that immunization trends of infants prior to the program were not increasing at a statistically different rate in high focus states relative to non-focus Indian states. I establish that the introduction of the program caused a sharp deviation away from trend in these states relative to their non-focus counterparts. I employ a difference-in-differences framework to identify the effect of the program and use detailed public health data to control for state and time varying factors that could pose potential threats to identification. The model estimates statistically significant increases in the range of 14-22 percentage points in the coverage of specific vaccines and the provision of full immunization in high focus states and a reduction in the incidence of infants with no immunization of up to 16 percentage-points. Finally, the paper makes use of additional information available as part of the DLHS surveys, to establish that the large increases in immunization coverage in high focus Indian states between 2004 & 2008 was most likely due to increased outreach as opposed to other improvements in the supply-chain of immunization services