Presenter(s) and Chair: Dr. Lingapandi and Prof. Richard Body / Codes: / Published: 21/04/2026
Summary
Dr. Lingapandi and Prof Body discuss a diagnostic cohort study that reviews the reliability of examination features in the prediction of wrist fractures. Two key strengths of the study were its prospective design and consecutive recruitment. Although orthopaedics consultation was recommended as follow-up for all patients recruited on 43.7% of patients recruited to the study had this. The reference standard included any combination of either radiograph, CT or MRI, which because of their variable sensitivities could introduce verification bias. A discussion of the receiver operating characteristic and its utility was also included
Key Learning Points
1. Consecutive recruitment increases the external validity of a study as it reflects the true population accurately
2. A power calculation for a diagnostic study should ideally be based on preliminary data that indicates the prevalence of the clinical presentation of interest and the sensitivities and specificities of the index tests of interest.
3. Loss-to-follow up is a major problem in cohort studies and particularly if there is unequal loss to follow up in different arms of the study this can result in attrition bias
4. The area-under-the-curve of the receiver operating characteristic is a measure of diagnostic accuracy
Original Journal Article Title: External validation of the deformity, edema, and pain in pronation model for predicting wrist fractures
Original Journal Article Reference: https://www.sciencedirect.com/science/article/pii/S0735675724000135
