External Validation of a Prognostic Model for Predicting Nonresponse Following Knee Arthroplasty

The external validity of the prognostic instrument was partially supported. While discrimination of the model was very similar to the recently developed instrument, calibration was poor indicating poor agreement between actual vs predicted probabilities of nonresponse. Western Ontario and McMaster Universities Arthritis Index and Kellgren and Lawrence grades show strong potential for use in future prognostic model development. Measurements of general mental health and obesity were not prognostic for nonresponse.