[Analysis of the scientific evidence of the combination therapy in benign prostatic hyperplasia]

The analysis of the scientific evidence of the combination therapy in Benign Prostatic Hyperplasia (BPH).

5 published studies about combination therapy in BPH were analysed following the criteria of the Evidence Based Medicine (EBM). Hypothesis, variables, internal validity, results relevance, and the external validity of every study were analysed.

Symptoms changes and maximal flow rate (Qmax) improvement were evaluated in four studies and only one analysed the BPH progression. Inclusion and exclusion criteria were similar in the 5 studies. The main reasons of a poor internal validity in 3 studies were the short follow-up, the missing percentage, the absence of a placebo group and a dosage bias. External validity were decreased in the 5 studies by the exclusion criteria and in 3 of them because high doses of alpha-blocker were given to achieve a therapeutic effect. The study with the highest scientific evidence (MTOPS) is the only that offers confidence intervals and number needed to treat.

The Qmax and the symptoms improvement found in all the studies has a moderate clinical relevance. MTOPS study shows that BPH progression has a low incidence that can be highly reduced by means of combination therapy.