Use of Multiple Data Sources and Individual Case Investigation to Refine Surveillance-Based Estimates of the HIV Care Continuum

Objectives:To assess the HIV care continuum among HIV-infected persons residing in Seattle and King County, WA, at the end of 2011 and compare estimates of viral suppression derived from different population-based data sources.Methods:We derived estimates for the HIV care continuum using a combination of HIV case and laboratory surveillance data supplemented with individual investigation of cases that seemed to be unlinked to or not retained in HIV care, a jurisdiction-wide population-based retrospective chart review, and local data from the CDC's Medical Monitoring Project and National HIV Behavioral Surveillance.Results:Adjusting for in- and out-migration of persons diagnosed with HIV, laboratory surveillance data supplemented with individual case investigation suggest that 67% of persons diagnosed with HIV and 57% of all HIV-infected persons living in King County at the end of 2011 were virally suppressed (plasma HIV RNA <200 copies/mL). The viral suppression estimates we derived from a population-based chart review and adjusted local Medical Monitoring Project data were similar to the surveillance-derived estimate and identical to each other (59% viral suppression among all HIV-infected persons).Conclusions:The level of viral suppression in King County is more than twice the national estimate and exceeds estimates of control for other major chronic diseases in the United States. Our findings suggest that national care continuum estimates may be substantially too pessimistic and highlight the need to improve HIV surveillance data.