HIV-1 Drug Resistance Testing: Health Outcomes Issues

Abstract

The cost of care for HIV-infected individuals, as for all chronically ill patients, is of increasing concern to healthcare providers and payers due to increasingly limited healthcare resources. Antiretroviral (ARV) drug therapy may cost in excess of 15000 Euros per year, yet evidence shows that total cost-of-care declines are due to decreased hospitalizations and clinic utilization [1–3]. Mostly these costs have been determined in aggregate for patient care and are only now being analysed for the various stages of disease. The majority of direct costs are for drugs and in-patient care, with diagnostics accounting for <5% of total costs (even in a clinical trial setting [4]). While the majority of patients in clinical practice are successfully suppressed below the limit of detection, many patients fail (as defined as a viral load above the limit of detection) within the medium to short term (1–2 years). Recent research has revealed that costs may rise by over 250 Euros per month after an episode of virological failure [5] and that each subsequent failure is more expensive. These preliminary data suggest there is an economic incentive to avoid ARV failure. Knowledge of viral resistance patterns in an individual may increase the ability of healthcare providers to select a successful and durable drug combination, and thus reduce ARV failure rates. However, from a budget perspective, the declining mortality rate in HIV disease means that the total cost of care for an HIV-infected population is rising rapidly. Thus, introduction of any additional tests or therapeutic agents that are priced higher than those already on the market is viewed with deep aversion by healthcare payers. It is therefore important to assess the impact of resistance testing on patients’ quality of life to inform decisions on the use of these tests in HIV disease. There are currently limited data available as to the actual effects of HIV-1 genotyping upon the total cost of patient care, and these data are only available for ARV-experienced patients, or from modelling studies based on these data. The only prospective economic study to date (based on the VIRADAPT study [6]) failed to show a statistically significant difference in the cost of care between patients who received genotyping and those who received standard-of-care. However, the study did show a trend (P=0.06) toward reduced costs, mainly through reduced drug costs and hospitalization costs [7]. Furthermore, it is possible that the use of a