Objectives: In 2015, Malawi piloted the HIV diagnostic assistant (HDA), a cadre of lay health workers focused primarily on HIV testing services. Our objective is to measure the effect of HDA deployment on country-level HIV testing measures.
Design: Interrupted time series analysis of routinely collected data to assess immediate change in absolute numbers and longitudinal changes in trends.
Methods: Data from all HDA sites were divided into two periods: predeployment (October 2013 to June 2015) and postdeployment (July 2015 to December 2017). Monthly rates of several key HIV testing measures were evaluated: HIV testing, including all tests done, new positives, and confirmatory testing. Syphilis testing at antenatal clinic (ANC) and early infant diagnosis were also assessed.
Findings: The number of patients tested for HIV per month increased after HDA deployment across all sex, age, and testing subgroups. The number of tests immediately increased by 35 588 (P = 0.031), and the postintervention trend was significantly greater than the preintervention slope (+3442 per month, P = 0.001). Of 7.4 million patients tested for HIV in the postdeployment period, 2.6 million (34%) were attributable to the intervention. The proportion of new positives receiving confirmatory tests increased from 28% preintervention to 98% postintervention (P < 0.0001). Syphilis testing rates at ANC improved, with 98% of all tests attributable to HDA deployment. The number and proportion of infants receiving DNA-PCR testing at 2 months experienced significant trend increases (P < 0.0001).
Interpretation: HDA deployment is associated with significant increases in total HIV testing, identification of new positives, confirmatory testing, syphilis testing at ANC, and early infant diagnosis testing.