A Cochrane review included 8 studies with a total of 1 137 subjects. Reminder packaging, i.e. incorporating a date or time for a medication to be taken in the packaging, showed a significant increase in the percentage of pills taken (six intervention groups in four trials; weighted mean difference 11%; 95% CI 6% to 17%). Notable heterogeneity occurred among the trials, I2 = 96.3%. Two trials provided data for the proportion of self-reported adherent patients, reporting a reduction in the intervention group which was not statistically significant, odds ratio = 0.89 (95% CI 0.56 to 1.40). No appropriate data were available for meta-analysis of different clinical outcomes.
Comment: The quality of evidence is downgraded by limitations in study quality and by inconsistency (variability in results across studies).