title: Survival effects of ZDV, ddI, and ddC in patients with CD4 < or = 50 cells/mm3.
abstract: Seven major clinical trials for the treatment of HIV-infected individuals are investigated. The treatments used in these trials were zidovudine, dideoxyinosine, dideoxycytosine, and one combination for patients with CD4 cell counts < 500 cells/mm3. Patients in each trial are partitioned into two subgroups based on their baseline CD4 cell counts: patients with CD4 < or = 50 cells/mm3 and patients with CD4 > 50 cells/mm3. The difference between treatment effects, using survival as a measure of effect, within each subgroup is calculated separately for each trial; this difference is referred to as "subgroup response." For each trial the difference between the subgroup responses is calculated and standardized. A meta-analysis is conducted over all seven trials for the differences between subgroup responses; the consistency of responses is evaluated across all trials among patients within baseline CD4 subgroups. Based on the result of this meta-analysis we conclude that there is no evidence that the treatment effects in patients with CD4 < or = 50 cells/mm3 are different from those among patients with CD4 > 50 cells/mm3. This result is observed in patients with different antiviral experience and different baseline characteristics. Risk ratios as well as chi 2 statistics are used to quantify the response rates in different subgroups. Kaplan-Meier curves of survival for these trials are depicted for all patients and each subgroup separately. In most of the trials the Kaplan-Meier curves for the patients with CD4 < or = 50 cells/mm3 resemble those for all patients.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Division of Biometrics, USFDA, Rockville, MD 20857, USA.
authors.forename: K
authors.initials: K
authors.lastname: Kazempour
authors.forename: L A
authors.initials: LA
authors.lastname: Kammerman
authors.forename: S S
authors.initials: SS
authors.lastname: Farr
mesh_terms: D000998:Antiviral Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D017322:Clinical Trials, Phase II as Topic; D017326:Clinical Trials, Phase III as Topic; D016049:Didanosine / Q000627:therapeutic use*; D004311:Double-Blind Method; D015658:HIV Infections / Q000188:drug therapy* / Q000401:mortality*; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D018570:Risk Assessment; D016019:Survival Analysis; D016047:Zalcitabine / Q000627:therapeutic use*; D015215:Zidovudine / Q000627:therapeutic use*
chemical_list: D000998:Antiviral Agents; D015215:Zidovudine; D016047:Zalcitabine; D016049:Didanosine