Routinely collected data such as hospital morbidity data (HMD) are increasingly used in studying
clinical outcomes among patients undergoing total joint replacement (TJR). These data are readily available and
cover large populations. However, since these data were not originally collected for the purpose of health research,
a rigorous assessment of their quality is required. We assessed the accuracy of the diagnosis of obesity in HMD and
evaluated whether the augmentation of HMD with actual weight and height of patients could improve their ability
to predict major in-hospital complications following total joint replacement in men.