RESUMO
BACKGROUND: The Mexican government is currently implementing strategies to improve and expand comprehensive treatment for people living with HIV. Limited data, however, are available on the benefits obtained and costs incurred by these strategies. OBJECTIVE: To estimate the effects of highly active antiretroviral therapy (HAART) on a cohort of people living with HIV and to estimate the cost of extending patients' lives. METHODS: A survival analysis was used to follow a dynamic cohort of 797 people receiving AIDS treatment in Mexico from 1982 to 2006. The Kaplan-Meier method was applied to estimate the probability of survival for different lengths of time starting on the date of diagnosis. The Cox's proportional hazards regression model was used to assess differences in AIDS mortality by antiretroviral therapy regimen, age and sex. RESULTS: The probability of survival after diagnosis without antiretroviral therapy (ART) was approximately 0.73 (95% CI 0.69-0.77) after the first year, 0.36 (95% CI 0.32-0.40) at 5 years, 0.28 (95% CI 0.24-0.33) at the tenth year, 0.26 (95% CI 0.21-0.31) at the fifteenth year and 0.22 (95% CI 0.14-0.30) thereafter. The results showed a longer life expectancy when patients took HAART (as opposed to monotherapy or dual therapy) from the beginning of their treatment. Results from the Cox model showed that those who started and continued on HAART were 7.1 (P < 0.01) times more likely to survive than those who received no treatment. Extending the length of life beyond 15 years after the initial diagnosis represents an accumulated cost of more than US$280,000.00 per individual.