Figure 21

The mean IIEF-Q4 score: major depressive disorder in remission.

Two sildenafil versus placebo trials conducted in participants with chronic congestive heart failure (CHF) were potentially combinable.^{102, 109} However, no meta-analysis was performed in view of the fact that the only common outcome reported in both trials was the mean IIEF “EF” domain score, for which numerical values of the measures of variability—SD or standard error (SE) could not be ascertained. One of the trials¹⁰² used a crossover design; it reported pre-crossover results graphically, without presenting numeric measures of the variability. In the same trial, no participant had any adverse events; therefore, no meta-analysis for adverse events was performed.

There were two trials that looked at patients with chronic renal failure on peritoneal dialysis. Although they were both eligible for meta-analysis (with respect to the mean IIEF “EF” domain score), ^{108, 123} they could not be pooled in view of a lack of complete numerical data (i.e., a SD or SE) in one of the trials.¹⁰⁸ A meta-analysis for adverse events was also not feasible, since in one of the trials¹⁰⁸ only one event was observed.

Meta-analysis was possible for sildenafil versus placebo trials involving hypertensive patients using multiple antihypertensive drugs (i.e., two or more different classes).^{143, 147} The meta-analyses were performed for efficacy outcomes (i.e., mean IIEF-Q3/Q4, GEQ-Q1, percentage of successful intercourse attempts) as well as all-cause and treatment-related specific adverse events (headache, flushing, and dyspepsia) (Figures 22–29).