Functional capacity after hip arthroplasty: a comparison between evaluation with three standard instruments and a personal interview

The aim of the present study was to compare the information obtained from three standard instruments used in physiotherapy and occupational therapy and with information acquired from an unstructured interview. Ten patients with osteoarthritis of the hip were consecutively picked from the waiting list at an orthopedic clinic. All were examined before and six months after arthroplasty. The study layout is a mixture of quantitative and qualitative evaluation. The three instruments used were SF-36 (self-reported health-related quality of life), FAS (an instrument for evaluation of lower extremity dysfunction), and the COPM (for evaluation of self-experienced activity level). All patients were also interviewed in a free, unstructured interview, and data were analyzed with a phenomenological approach. All methods could describe function and activity status of the patients very well, and they were also responsive to postoperative improvement. Together the three instruments gave such good information that almost no extra information was obtained through the interviews. On the other hand, the interviews served as powerful validation of the three instruments. The information in the three separate instruments is qualitatively different, and one instrument cannot replace another. They cannot be replaced by the interview either, because the instruments provide the therapist with specific and structured information that is important for further treatment planning and follow-up.