Effect of XXXX -derivative diet pills on cardiac valves: a meta-analysis of observational studies.

@entity4899 @entity1 @entity339 @entity337 @entity340
BACKGROUND: @entity4899 -derivative diet pills were withdrawn from the market in 1997 because of an association with @entity340 , but subsequent estimates of the prevalence of this condition have varied widely. We systematically reviewed evidence regarding the prevalence of @entity340 after @entity4899 exposure. METHODS: We searched multiple databases with multiple search terms. Conference proceedings from 1997 onward were searched by index. Authors of eligible studies were contacted to identify unpublished works. Selection criteria were liberally determined. Ten of the identified 11 articles met these criteria. Reviewers assessed the studies' methodologic quality by use of a standard form to evaluate selection, attrition, performance, and detection bias. The studies were analyzed in 2 groups on the basis of length of exposure (<90 days or >90 days). The Mantel-Haenszel method was used to summarize data. Quantitative and qualitative tests for heterogeneity were performed. Tests for publication bias were also done. RESULTS: Tests for heterogeneity were nonsignificant after removing 1 outlier trial. The pooled prevalence of @entity340 meeting Food and Drug Administration criteria (at least mild @entity337 or at least moderate @entity339 ) among @entity1 treated for >90 days was 12.0% compared with 5.9% for the unexposed group (prevalence odds ratio 2.2, 95% CI 1.7-2.7). The combined analyses also identified a small but statistically significant increase in @entity339 not previously identified by individual studies (exposed 3.5%, unexposed 1.8%, prevalence odds ratio 1.6, 95% CI 1.05-2.3). Among @entity1 exposed for <90 days, a trend toward more regurgitation was not statistically significant by either combined Food and Drug Administration criteria (exposed 6.8%, unexposed 5.8%, prevalence odds ratio 1.4, 95% CI 0.8-2.4) or by individual valve. CONCLUSIONS: These data indicate that @entity4899 -associated @entity340 is less common than initially reported, but still present in 1 of 8 @entity1 treated for >90 days.
