BJP-2000-BECH-421-8

An odds ratio equal to one indicates that there is no

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Unformatted text preview: of heterogeneity. An odds ratio equal to one indicates that there is no difference between the two treatment groups. A value greater than one indicates that more patients in the fluoxetine group were classified as being in partial remission, and therefore that fluoxetine was better; a value of less than one indicates that more patients in the control group were classified as being in partial remission, and therefore that control treatment (placebo or TCA) was better. However, in the analyses of early treatment discontinuations an odds ratio of less than one indicates fewer discontinuations in the fluoxetine group, and that fluoxetine was better. Conversely, a log odds ratio of greater than one indicates that there were fewer discontinuations in the control (placebo or TCA) group, and therefore that the control treatment was better. Effect size for the meta-analysis of quantitative data Effect size analysis was introduced by Glass (1976) as a means of combining data from several independent clinical trials. In our analysis the effect size was defined as the mean change of HDRS from baseline to end-point of the two groups under investigation divided by the standard deviation of the change score (Cohen, 1977). The 95% confidence intervals (95% CIs) were calculated according to Hedges & Olkin (1985). Data for all randomised patients with at least one post-baseline visit (endpoint analysis), using a `last-observationcarried-forward' technique, were included in these analyses. The method of calculation used is in accordance with that described by Whitehead & Whitehead (1991), using either a fixed or random effects model as deemed appropriate. As for the meta-analysis of binary data, a test of heterogeneity (Cochran's Q-test; Laird & DerSimonian, 1986) and a test of significance of the effect size were performed. RESULTS General results The list of trials showing some details of their characteristics, for example, number of investigators, number of patients, dose of medication, are given in Tables 1a and 1b (further details and references of published trials can be obtained from...
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This note was uploaded on 01/16/2013 for the course BMS 620 taught by Professor Panavalil during the Summer '12 term at Barry Univesity.

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