J Copas | PubMed Health

PubMed2000

Meta-analysis, funnel plots and sensitivity analysis.

Publication bias is a major problem, perhaps the major problem, in meta-analysis (or systematic reviews). Small studies are more likely to be published if their results are 'significant' than if their results are negative or inconclusive, and so the studies available for review are biased in favour of those with positive outcomes. Correcting for this bias is not possible without making untestable assumptions. In this paper, a sensitivity analysis is suggested which is based on fitting a model to the funnel plot. Some examples are discussed.

Journal Article↗

PubMed1991

Schizophrenia, bipolar disorder and depression. A discriminant analysis, using 'lifetime' psychopathology ratings.

Discriminant and canonical variate analyses were performed using 302 patients, on whom ratings of lifetime psychopathology and course of illness has been made. DSM-III diagnoses were used to form the criterion groups. Bipolar disorder emerged as a distinct grouping, but there are reasons for dissatisfaction with its definition. The remaining patients formed a 'schizodepressive continuum', but this also had a tendency to bimodality. It is possible that the distinction between schizophrenia and depression was obscured by inadequacies in the data and the inclusion of excessive numbers of patients with schizoaffective depression in this study.

Adolescent↗