Has mortality from XXXX decreased over time?: A systematic review.

@entity1 @entity649 @entity23 @entity647
RATIONALE: It is commonly stated that mortality from @entity649 ( @entity649 ) and @entity647 ( @entity647 ) is decreasing. OBJECTIVES: To systematically review the literature assessing @entity649 mortality over time and to determine @entity1 - and study-level factors independently associated with mortality. METHODS: We searched multiple databases (MEDLINE, EMBASE, CINAHL, Cochrane CENTRAL) for prospective observational studies or @entity23 ( @entity23 ) published during the period 1984 to 2006 that enrolled 50 or more @entity1 with @entity647 / @entity649 and reported mortality. We pooled mortality estimates using random-effects meta-analysis and examined mortality trends before and after 1994 (when a consensus definition of @entity647 / @entity649 was published) and factors associated with mortality using meta-regression models. MEASUREMENTS AND MAIN RESULTS: Of 4,966 studies, 89 met inclusion criteria (53 observational, 36 @entity23 ). There was a total of 18,900 @entity1 (mean age 51.6 years; 39% female). Overall pooled weighted mortality was 44.3% (95% confidence interval [CI], 41.8-46.9). Mortality decreased with time in observational studies conducted before 1994; no temporal associations with mortality were demonstrated in @entity23 (any time) or observational studies (after 1994). Pooled mortality from 1994 to 2006 was 44.0% (95% CI, 40.1-47.5) for observational studies, and 36.2% (95% CI, 32.1-40.5) for @entity23 . Meta-regression identified study type (observational versus RCT, odds ratio, 1.36; 95% CI, 1.08-1.73) and @entity1 age (odds ratio per additional 10 yr, 1.27; 95% CI, 1.07-1.50) as the only factors associated with mortality. CONCLUSIONS: A decrease in @entity649 mortality was only seen in observational studies from 1984 to 1993. Mortality did not decrease between 1994 (when a consensus definition was published) and 2006, and is lower in @entity23 than observational studies.
