We have developed a comprehensive system of assessment of patients undergoing total hip and total knee replacement. This new unified scoring system provides a single instrument to measure the disability of patients suffering from primary osteoarthritis of either hip or knee. This instrument will be used to prioritize these patients for a single waiting list and it will be used as an outcome measure to assess their progress after their hip or knee replacement surgery. The scoring system is comprised of two parts carrying equal point value. The subjective part is an assessment tool completed by the patients themselves. It is comprised of 12 Items covering every aspect of the disability associated with hip and knee arthritis. The objective part is an assessment tool completed by the treating physician or a trained joint arthroplasty nurse. The first stage of this project comprised of formulation of a preliminary questionnaire after a thorough assessment of 50 patients suffering from hip or knee arthritis. We then organised multiple clinical sessions with focus groups to critically appraise the content of our new questionnaire. The focus group patients were invited to give their comments about any issues not discussed previously. This preliminary questionnaire was then converted into a set of closed questions and was divided into a subjective and an objective part. The second stage of this project involved assignment of scales and scale grading for different components of the objective part. This involved the process of magnitude estimation. 75 patients, 25 consultants and 5 nurses were involved in this process. The third stage of this project involved a comprehensive assessment of this new scoring system in terms of internal consistency, internal consistency reliability, inter-observer reliability, test-retest reliability, face validity, content validity and construct validity. The process of validation involved comparison of our scoring system with the relevant parts of SF36, Oxford knee score, WOMAC and AIMS. It has also been tested on the first subset of post operative patients to measure its responsiveness. Cronbach’s alpha was used for internal consistency and Pearson’s correlation coefficients were used for different correlation studies. Our new scoring system has shown a very satisfactory internal consistency. The inter-rater agreement and the test-retest reliability data on the first set of 100 patients are very promising as well. The instrument has shown a significant effect size in the first set of post-op patients 4 months after their surgery. Our new scoring system will provide an easy to apply and comprehensive instrument for a need based waiting list for patients undergoing either THR or TKR. It will also be a reliable and sensitive outcome measure to monitor these patients’ progress in the post-operative period.
