To assess the quality and the overall findings of a large dataset of language restricted and language inclusive systematic reviews, including both conventional medicine and complimentary and alternative medicine from systematic reviews published across several databases between 1985 and 1999.
Level of Investigation
Analytical
Summary of Findings
Language restrictions did not appear to bias the estimates of a conventional intervention’s effectiveness but did affect the results of a complimentary and alternative systematic review. If languages other than English reports were excluded this resulted in a reduced intervention effect, 63% on average (difference in the ratio of odds ratios of intervention = 1.63; 95% confidence interval: 1.03 to 2.60).
Number of systematic reviews included
130
Number of eligible systematic reviews assessed
280
Does the article have a publicly available protocol?
No
Did the review team include both methodological and clinical experts?
Not Applicable
Sampling strategy for obtaining the systematic reviews under assessment
Comprehensive searches on a particular topic (clinical or methodological)
Was the sample size of systematic reviews subject to any formal sample size or power calculation?
Yes
Were any or all of the study selection and data extraction performed in duplicate?
No
Were any statistical adjustments made to correct for confounding?
No
Are the methods of the article described in enough detail to replicate the study?
