An application of meta-analysis techniques in the evaluation of adverse experiences with antihypertensive agents

Purpose: To investigate the profiles of adverse events (AEs) in randomized controlled trials of antihypertensive agents therapy with the technique of meta-analysis.

Methods: A total of 620 articles were selected from MEDLINE, EMBASE, JAPIC-DOC, JMEDICINE and manual searching. Two independent reviewers examined the 620 selected articles according to the following criteria: (1) the methods of randomization, (2) making for allocating treatments, (3) therapeutic class of drugs, (4) sample sizes, (5) duration of the treatment, (6) primary endpoint, (7) reporting method for all adverse events, (8) method of monitoring AEs, and (9) incidence rates of all reported AEs. To combine the risk difference and risk ratios of incidence between CCBs and beta blockers or diuretics, the method of DerSimonian and Laird based on random effect model was applied.

Results: A total of 3073 patients were included in this meta-analysis of serious adverse events (SAEs). There was no significant difference in the total incidence of SAEs between CCBs and diuretics or between CCBs and beta blockers. We found that patients treated with CCBS had 0.14% fewer SAEs compared with the patients treated with diuretics. Contrarily, the patients treated with CCBs had 0.29% more SAEs compared with the patients treated with beta blockers. There was a significant difference between the patients treated with CCBs and those treated with diuretics in the symptoms with headache and oedema. With respect to the comparison between CCBs and beta blockers, flushing occurred 8.75% more frequently in the CCBs group than in the beta blockers group.

Conclusion: A meta-analysis can be applied to safety analyses of data obtained in clinical trials if all of the RCT articles used include a complete description of adverse experiences.