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Meta-analysis of randomized, double-blind, placebo-controlled trials of melatonin in Alzheimer's disease

Wang YY, Zheng W, Ng CH, Ungvari GS, Wei W, Xiang YT

International journal of geriatric psychiatry, 2017

462 participants

Abstract

OBJECTIVE: This is a meta-analysis of randomized controlled trials (RCTs) of the efficacy of melatonin in Alzheimer's disease (AD).

METHODS: Both English (PubMed, PsycINFO, Embase, Cochrane Library databases, and the Cochrane Controlled Trials Register) and Chinese (WanFang Database, Chinese Biomedical Database, and China Journal Net) databases were systematically and independently searched by two authors from their inception until 1 March 2016. Weighted and standard mean differences (SMDs), risk ratio (RR) ±95% confidence intervals (CIs) were calculated. In all cases, the random effects model was used.

RESULTS: Seven studies (n = 462) with the duration ranging from 10 days to 24 weeks were identified and analyzed. AD patients receiving melatonin treatment showed prolonged total sleep time at night (n = 305; SMD: 0.26, 95% CI: 0.01 to 0.51, I2 = 9%, p = 0.04). Melatonin did not improve cognitive abilities assessed by the mini-mental state examination and the Alzheimer's Disease Assessment Cognitive Subscale. The discontinuation rate was similar between the melatonin and placebo groups (n = 453, RR = 0.77, 95% CI: 0.51 to 1.16, I2 = 0%, p = 0.21).

CONCLUSION: Melatonin appears to be effective and safe in improving sleep quality in patients with AD. Copyright © 2016 John Wiley & Sons, Ltd.

How strong is the evidence?

Evidence Hub reads this as a meta-analysis, done in people. Its evidence level is 1 of 5 (Highest · pooled evidence). Pooled evidence from several studies sits at the top of the evidence pyramid. Reported size: 462 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

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