Population-Based Linkage of AIDS and Cancer Registries: Importance of Linkage Algorithm Review Article

Background This study evaluates linkage algorithms used in 1997 for Los Angeles County by the AIDS-Cancer Match Registry to estimate the risk of cancer among people with HIV/AIDS. Methods In 2001, a linkage between the Los Angeles County cancer and AIDS registries using a five-pass algorithm was compared with the 1997 linkage results that used a two-pass algorithm. Results The five-pass linkage detected all of the previously identified matches (6571) as well as another 431 (6.2%), which had been missed. Conclusions Record linkage methodologic decisions can markedly affect matching sensitivity and specificity. It is probable that the AIDS-Cancer Match Registry two-pass linkage has underestimated the risks of some cancers among people with AIDS.