Description of the quality characteristics of the included and excluded studies in the Meta-Analysis of 5-HTTLPR polymorphisms and Post-traumatic Stress Disorder (PTSD).

$Representativeness of cases included all eligible cases with outcome of interest over a defined period of time, all cases in a defined catchment area, all cases in a defined hospital or clinic, group of hospitals, health maintenance organization, or an appropriate sample of those cases (e.g. random sample).#Representativeness of controls assesses whether the control series used in the study is derived from the same population as the cases and essentially would have been cases had the outcome been present and included community and clinical controls within the same community or hospitalized population as cases.&If Yes, the % of the different ethnics groups are provided in brackets.AS: Asiatic. EA: Euro-American; AA: Afro-Americans; Af: African; Eu: Europeans.†HWE: Hardy-Weinberg Equilibrium; ‡TQS: Total Quality Score.