Differential access in the receipt of antiretroviral drugs for the treatment of AIDS and its implications for survival.

Abstract

TREATMENT of acquired immunodeficiency syndrome (AIDS) has become more promising yet potentially more costly in recent years with development of protease inhibitors and nonnucleoside analog reverse transcriptase inhibitors. Such drug treatment protocols have been found to suppress viral replication, increase production of CD4⁺ cells, reduce morbidity, and prolong survival.^1-4 Recently published research documenting such findings is based on selected samples of patients treated at human immunodeficiency virus (HIV) clinics. There are significant advantages to studying clinical samples because detailed information is available on patient socioeconomic characteristics, attendance at clinical follow-up appointments, and laboratory data such as CD4 cell counts and viral load. Such information is important in understanding the relation between access, compliance, degree of immunosuppression, and clinical response. Nonetheless, findings based on clinical samples are subject to sample selection bias if such persons living with HIV or AIDS (PLWHAs) are more prone to take the recommended medications as prescribed by their physicians than PLWHAs who are not treated at HIV specialty clinics. Another source of selection bias is that such patients tend to be relatively homogeneous with respect to demographic and socioeconomic characteristics. If this is the case, one cannot generalize the results derived from selected clinical samples to the entire population of PLWHAs.