Background:  Chile, a middle-income country (per capita NGP of US₄,603) of 15.6 million people, began an expanded access program to antiretroviral therapy (ART) in late 2001 to HIV patients from the public health system (70% of the population). The centralized program provides ART drugs, CD4, viral load, and genotype monitoring, plus supplementary budget for some other anti infective drugs to the 31 participating centers throughout the country. Patients from 26 of these centers are enrolled in a national AIDS cohort (ChiAC) for follow-up and general data collection and exchange. The purpose of this paper is to present the model of the ChiAC and some preliminary data on efficacy.

Methods:  We reviewed of the ChiAC database.

Results:  ChIAC is an organization whose member centers take care of patients according to national guidelines and share information regarding HIV management; all are in contact with a central administrative office where data are periodically sent, reviewed, and analyzed. An intranet with electronic data capture and exchange is under construction. As of August 2003 the expanded access program had approved ART for 4178 patients (100% of requests). At the end of October 2003 >3300 were to be included in the ChiAC (>79%);   52.9% of patients had been treatment-naive. For 1514 patients baseline data were complete, and for 1068 follow-up data are complete until August 2003 and are presented. Most patients were in advanced disease at baseline:  49% had clinical AIDS, and only 21% were in stage A; 79.5% had CD4 <200 x mm³ and 51% <100. Primary ART in naïve patients has been AZT/3TC or d4T/3TC plus nevirapine, efavirenz or indinavir. By 6 months of  follow-up, 53 patients (5.0%) had died:  5.8%  ART-naïve, 3.3% non-naïve, 10.4% of those with baseline CD4 x mm³ <50, 4.7% at  51 to 100, 1%  at 101 to 200, and 0.9% at >201. While on ART, 31 patients (2.9%) had stage progression and 81 (7.7%) stopped ART because of toxicity. Death and progression were strongly associated with baseline CD4 <100 x mm ³.

Conclusions:  An expanded access program to ART in a middle income country is possible. A national cohort model may be useful to evaluate the program and to improve its operation, besides allowing scientific information collection that may help to improve the results and to be useful to countries with similar epidemic and economic scenarios.

Keywords: antiretroviral therapy; national cohort; middle income country