biostudies-literatureUnknown6Shea B<h4>Background</h4>Systematic reviews (SRs) must be of high quality. The purpose of our research was to compare the methodological and reporting quality of original versus updated Cochrane SRs to determine whether updating had improved these two quality dimensions.<h4>Methods</h4>We identified updated Cochrane SRs published in issue 4, 2002 of the Cochrane Library. We assessed the updated and original versions of the SRs using two instruments: the 10 item enhanced Overview Quality Assessment Questionnaire (OQAQ), and an 18-item reporting quality checklist and flow chart based upon the Quality of Reporting of Meta-analyses (QUOROM) statement. At least two reviewers extracted data and assessed quality. We calculated the percentage (with a 95% confidence interval) of 'yes' answers to each queBMC medical research methodology27https://www.ebi.ac.uk/biostudies/studies/S-EPMC1569863biostudies-literatureDoes updating improve the methodological and reporting quality of systematic reviews?PMC1569863Shea BHamel CGrimshaw JMBouter LMBoers MfalseDoes updating improve the methodological and reporting quality of systematic reviews?<h4>Background</h4>Systematic reviews (SRs) must be of high quality. The purpose of our research was to compare the methodological and reporting quality of original versus updated Cochrane SRs to determine whether updating had improved these two quality dimensions.<h4>Methods</h4>We identified updated Cochrane SRs published in issue 4, 2002 of the Cochrane Library. We assessed the updated and original versions of the SRs using two instruments: the 10 item enhanced Overview Quality Assessment Questionnaire (OQAQ), and an 18-item reporting quality checklist and flow chart based upon the Quality of Reporting of Meta-analyses (QUOROM) statement. At least two reviewers extracted data and assessed quality. We calculated the percentage (with a 95% confidence interval) of 'yes' answers to each que2006-01-01T00:00:00Z2006 Jun2025-04-26T02:19:23.78Z2019-03-27T01:45:56ZS-EPMC15698631677203010.1186/1471-2288-6-27