National characteristics and trends in antiretroviral treatment in Australia can be accurately estimated using a large clinical cohort.

objectivesCohort studies are often used as a national surveillance tool to monitor trends in HIV treatment and morbidity outcomes. However, there are limited studies validating the accuracy of using cohorts as a representation of the overall HIV-positive population. We compared data from a large Australian HIV-positive cohort study (Australian HIV Observational Database [AHOD]) and a 10% longitudinal sample from Australia's subsidized prescription medication scheme (Pharmaceutical Benefits Scheme [PBS]) to assess the use of cohorts for providing representative data for surveillance and monitoring purposes. STUDY DESIGN AND

settingBasic demographics and treatment information from July 1, 2013, to March 31, 2016, were divided into half-yearly periods to compare HIV trends between AHOD (n = 2,488) and PBS (n = 18,409) patients.

resultsIn both data sets, most patients were men, aged above 50 years, and primarily resided in New South Wales. Both data sets revealed a significant shift toward the increased use of integrase strand transfer inhibitors and a gradual decline in the use of protease inhibitors and nonnucleoside reverse-transcriptase inhibitors among the treated population in Australia. Similarly, a substantial increase in the use of once daily, single-tablet, fixed-dose combination regimens was also observed.

conclusionOur results show that observational cohort studies can serve as useful surrogate surveillance tools for monitoring patient characteristics and HIV treatment trends.