When little or no data directly comparing two treatments are available, investigators often rely on indirect comparisons from studies testing the treatments against a control or placebo.
One approach to indirect comparison is to pool findings from the active treatment arms if the original controlled trials.
This approach offers no advantage over a comparison of observational study data and is prone to bias.
We present an alternative model that evaluates the differences between treatment and placebo in two sets of clinical trials, and preserves the randomization of the originallys assigend patient groups.
We apply the method to data on sulphamethoxazole-trimethoprim or dapsone/pyrimethamine as prophylaxis against Pneumocystis carinii in HIV infected patients.
The indirect comparison showed substantial increased benefit from the former (odds ratio 0.37,95% Cl 0.21 to 0.65), while direct comparisons from randomized trials suggests a much smaller difference (risk ratio 0.64,95% Cl 0.45 to 0.90 ; p-value for difference of effect=0.11).
Direct comparisons of treatments should be sougth.
When direct comparisons are unavailable, indirect comparison meta-analysis should evaluate the magnitude of treatment effects across the studies, recognizing the limited strength of inference.
Mots-clés Pascal : SIDA, Virose, Infection, Pneumonie, Pneumocystis carinii, Sporozoa, Protozoa, Chimiothérapie, Traitement, Méthodologie, Métaanalyse, Homme, Etude comparative, Essai clinique, Randomisation, Antibactérien, Antiinfectieux, Epidémiologie, Immunopathologie, Immunodéficit, Appareil respiratoire pathologie, Poumon pathologie
Mots-clés Pascal anglais : AIDS, Viral disease, Infection, Pneumonia, Pneumocystis carinii, Sporozoa, Protozoa, Chemotherapy, Treatment, Methodology, Metaanalysis, Human, Comparative study, Clinical trial, Randomization, Antibacterial agent, Antiinfectious, Epidemiology, Immunopathology, Immune deficiency, Respiratory disease, Lung disease
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0422532
Code Inist : 002B02S02. Création : 19/12/1997.