[Decision analysis: diagnostic approach in HIV infection associated chronic diarrhea]

Chronic diarrhea is still a problem of difficult management in patients with AIDS, even in the HAART (Highly Active Antiretroviral Therapy) era.

To establish the most appropriate diagnostic procedure for HIV infected patients, with CD4 count below 200 cells/ml and chronic diarrhea, starting on HAART.

Using a decision tree as the tool of a decision analysis, two alternatives were considered for the ethiologic diagnosis in AIDS associated chronic diarrhea. The compared alternatives were a minimal evaluation (stool culture and parasite stool examination), and complete evaluation (adding endoscopies with intestinal biopsies). The decision tree was constructed by TreeAge Data 32 software. Diagnostic and therapeutic data for both alternatives were obtained from medical publications. The outcome was the reported survival estimation for HIV infected patients with CD4 level bellow 200 cells/ml, starting HAART, with and without chronic diarrhea.

In the basic analysis, as well as in the sensitivity analysis, a complete evaluation was the alternative that showed the highest expected value: 7.79 years of survival. The minimal evaluation showed a value of 7.05 years of survival.

In HIV infected patients with chronic diarrhea and CD4 count below 200 cells/ml, starting on HAART, digestive endoscopies with biopsy samples are the best diagnostic approach.