Objective To evaluate the effectiveness and safety of doxepin in the treatment of primary insomnia. Methods We searched The Cochrane Library (Issue 4, 2009), PubMed (1966 to December 2009), EMbase (1974 to December 2009), ISI (1961 to December 2009), CNKI (1979 to December 2009), VIP (1989 to December 2008), CBM (1978 to December 2009), and WANFANG Data (1998 to December 2009). We also searched the correlated grey literature and conference literature for complement. Data were extracted, methodologically evaluated, and cross-checked by two reviewers independently. RevMan 5.0 was used for statistical analysis. Results One randomized controlled trial and three cross trials involving 171 patients were included. The results of meta-analyses showed that total sleep time (TST), wake time during sleep (WTDS), wake time after sleep (WTAS), and sleep efficiency (SE) were improved by low and medium dosage of doxepin (1-25 mg) with statistically significant difference compared with placebo. On the contrary, most indicators of sleep quality had no statistically significant difference between high dose doxepin (50 mg) and placebo. While the sleeping structural indicators of rapid eye movement sleep (REM), rapid-eyemovement latency (REM-L), and sleep stage II (St.II) were changed by high and medium dosage of doxepin (25-50 mg) with statistically significant difference. Conclusions Low and medium dosage of doxepin (1-25 mg) is effective in improvement of the sleep quality in patients with primary insomnia, but it is necessary to concern the side effects and the effects on sleep structure when treating primary insomnia with medium dosage of doxepin (25 mg). High dosage of doxepin (50 mg) is not recommended to treat primary insomnia. However, this conclusion still needs clinical trials to be further validated.
Objective To survey and analyze the quality assessment of the included studies in the Overviews of reviews (Overviews), so as to provide methodology references for Overviews authors. Methods A computerized search was performed for collecting Overviews in The Cochrane Library (Issue 1, 2010), PubMed, EMBASE, and CBM, and the search time ended by December, 2009. Then the relevant data, such as assessment standard etc, were extracted, and the staple standards were analyzed. Results A total of 43 typical Overviews were included. Thirty-two (74.4%) of them assessed the methodology quality of the included systematic reviews with different standards, including OQAQ (34.9%/15), AMSTAR (9.1%/3), Checklist from DARE (4.6%/2), Assendelft scale (4.6%/2), Effective Public Health Practice Project standards (2.3%/1), self-formulated standards (14.0%/ 6), syntaxic standards (2.3%/1), and other standards (4.6%/2). Ten Overviews (23.6%) assessed the quality of evidence, including eight (18.6%) applied the GRADE system. Only 7 studies (16.3%) assessed the quality of evidence and applied the GRADE system as well. Conclusion The quality assessment in Overviews includes the assessment of both methodological quality and evidence quality. But most Overviews do not assess comprehensively. The methodological quality standards applied in current Overviews are numerous and no standard is acknowledged. Yet, the OQAQ and AMSTAR are applied widely and recommended because they are comprehensive and easy to be conducted. It suggests that Overviews authors should choose appropriate methodological quality assessment standards according to concrete conditions. The GRADE system is much more comprehensive and systematic than other systems, so it is recommended that Overviews authors should apply GRADE to assess the quality of evidence in their studies in order to make the study results more comprehensive and easier for clinical application.