Obesity in individuals with schizophrenia: a case controlled study in Scotland.

Background Despite extensive clinical concern about rates of obesity in patients with schizophrenia, there is little evidence of the extent of this problem at a population level. Aims To estimate levels of obesity in a national population sample by comparing patients with schizophrenia with matched controls. Method We calculated levels of obesity for each patient with schizophrenia from the national Primary Care Clinical Informatics Unit database (n=4658) matched with age, gender and neighbourhood controls. Results We demonstrated a significant increased obesity hazard for the schizophrenia group using Cox regression analysis, with odds ratio (OR) of 1.94 95% CI 1.81-2.10) (under the assumption of missing body mass index (BMI) indicating non-obesity) and OR=1.68 (95% CI 1.55-1.81) where no assumptions were made for missing BMI data. Conclusions People with schizophrenia are at increased risk of being obese compared with controls matched by age, gender and practice attended. Priority should be given to research which aims to reduce weight and increase activity in those with schizophrenia.