Psychological treatments for chronic post-traumatic stress disorder

Abstract

Where possible, meta-analysis was used to Where possible, meta-analysis was used to synthesise data, including additional meta-synthesise data, including additional meta-analyses for anxiety and depression mea-analyses for anxiety and depression mea-sures where available, and numbers leaving sures where available, and numbers leaving the study early, using Review Manager. the study early, using Review Manager. Post-treatment data (or change scores if Post-treatment data (or change scores if reported instead of post-treatment data) reported instead of post-treatment data) for the psychological treatment and control for the psychological treatment and control condition were entered in the Review condition were entered in the Review Manager tables. Dichotomous outcomes Manager tables. Dichotomous outcomes (PTSD diagnosis and leaving the study early (PTSD diagnosis and leaving the study early for any reason) were analysed as a relative for any reason) were analysed as a relative risk number and were calculated on an risk number and were calculated on an intention-to-treat basis (i.e. a 'once ran-intention-to-treat basis (i.e. a 'once ran-domised always analyse' basis). This makes domised always analyse' basis). This makes the conservative assumption that all partici-the conservative assumption that all partici-pants who ceased to engage in the study pants who ceased to engage in the study had an unfavourable outcome, e.g. they left had an unfavourable outcome, e.g. they left because the treatment was not acceptable because the treatment was not acceptable and still had a diagnosis of PTSD. Continu-and still had a diagnosis of PTSD. Continu-ous outcomes were analysed as standardised ous outcomes were analysed as standardised mean differences (SMDs) to allow for ease of mean differences (SMDs) to allow for ease of comparison across studies. It was not poss-comparison across studies. It was not poss-ible to obtain intention-to-treat data for most ible to obtain intention-to-treat data for most of the trials, and we therefore used completer of the trials, and we therefore used completer data for all continuous outcomes. data for all continuous outcomes. For consistency of presentation all data For consistency of presentation all data were entered into Review Manager in such were entered into Review Manager in such a way that negative effect sizes or relative risk a way that negative effect sizes or relative risk numbers less than 1 represented an effect that numbers less than 1 represented an effect that favoured the active treatment compared with favoured the active treatment compared with the waiting-list control. Data were pooled the waiting-list control. Data were pooled from more than one study using a fixed-from more than one study using a fixed-effects meta-analysis except where heteroge-effects meta-analysis except where heteroge-neity was present, in which case a random-neity was present, in which case a random-effects model was used as described below. effects model was used as described below.