A meta-analysis 1 comparing any pharmacological treatment for insomnia with placebo included 24 RCTs, with a total of 2417 participants aged > 60 years. Total sleep time increased (mean 25.2 minutes, p < 0.001), and the number of night time awakenings decreased (0.63, P < 0.001) with sedative use compared with placebo. The number needed to harm (NNH) for sedative hypnotics compared to placebo is 6 (95% CI 4.7 to 7.1; all adverse events reported in 17 studies, n=2220). Adverse cognitive events were 4.78 times more common (95% CI 1.47-15.47, p < 0.01); adverse psychomotor events were 2.61 times more common (1.12-6.09, p > 0.05), and reports of daytime fatigue were 3.82 times more common (1.88-7.80, p < 0.001).
Comment: The grade of evidence is downgraded by possible publication bias (a funnel plot suggested that the published studies favoured positive results), imprecision (sparse data on serious events including six falls and one motor vehicle accident), and indirectness of evidence for some adverse outcome measures (performance tasks). The authors conclude that the benefits of these drugs may not justify the increased risk, particularly if the patient has additional risk factors for cognitive or psychomotor adverse events.
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