Validation of the Danish version of the constipation risk assessment scale (CRAS)

The Constipation Assessment Scale (CRAS) was developed in order to enable the prediction of the risk of developing constipation. The scale needs validation in acute and elective patients with common disorders.Two hundred and six acute patients with hip fracture and 200 elective patients with total knee or hip replacement were included. They were assessed with CRAS before surgery and their defecation pattern, stool consistency and degree of straining were measured at admission and 30 days after surgery.The prevalence of constipation was 0.49 for the acute patients and 0.34 for the elective patients. Sensitivity was 0.67 and 0.57. Specificity was 0.54 and 0.52. Positive predictive value was 0.59 and 0.38, whereas the negative predictive value was 0.63 and 0.7.When used in an orthopaedic ward, the prognostic accuracy of CRAS is poor and it cannot be recommended as a screening tool.