Impact of antiretroviral therapy in mortality of Chilean HIV(+) patients: a case-control study

Background: Combined antiretroviral therapy (AVR) has shown a protective effect (PE) on morbidity and survival in HIV(+) patients of industrialised countries where triple-drug therapy (ARV-3) is standard. In Chile the public health system began providing double-drug therapy in 1997 (ARV-2) with 2 reverse transcriptase inhibitors. Aim: To assess the impact of ARV in morbimortality of HIV (+) patients in Chile after a year of follow up. Patients and methods: Retrospective case-control (1:1) study. Cases were 97 patients followed during 1997 for 6 or more months and dying during that period. Each case had a control of the same gender and CDC stage, similar age and CD4 count, but surviving a same period of follow up. A comparison of ARV before and during follow up (rate and type) was done. P carinii prophylaxis, pneumococcal immunization at baseline or follow up, frequency of hospital admissions and occurrence of opportunistic infections in both groups were assessed. Odds ratio (OR) for mortality, hospitalisation and opportunistic infections in ARV user, as well as treatment PE were calculated. Results: Twenty four (24.7%) cases and sixty six (68%) controls received ARV during follow up (p< 0.001), OR was 0.15 (CI 95% 0.08-0.3), p < 0.001, the PE was 6.6 for ARV users versus non users, among cases 19 patients received ARV-2 and five received ARV-3. Among controls, 41 patients received ARV-2 and 25 received ARV-3. There differences established an OR of 0.20 (CI 95% 0.09-0.04) and a PE of 5 for ARV-2 versus no ARV. For ARV-3 compared with no ARV the OR 0.08 (CI 95% 0.003-0.26), and the PE 12.5. Fifty three (54.6%) cases and 13 (13.4%) controls required hospital admission, OR 0.49 (CI 95% 0.25-0.94), p=0.03, and PE of 2.04 of ARV versus no ARV; 82 (85.3%) cases and 50 (51%) controls had opportunistic infections, OR 0.5 (CI 95% 0.26-0.96), p=0.03 and PE of 2 for ARV versus no ARV. There were no significant differences in prior ARV, prophylaxis and immunisation between cases and controls. Conclusions: This study showed the high impact of ARV in short term morbimortality of HIV(+) patients and the need to implement antiretroviral therapy to all patients as an official health policy. This study did not answer the question of the role, if any, of weaker-than standard antiretroviral therapy.