Evaluating waiting time effect on health outcomes at admission: a prospective randomized study on patients with osteoarthritis of the knee joint

To evaluate the effect of waiting on health-related quality of life (HRQoL), pain and physical function in patients awaiting primary total knee replacement (TKR) due to osteoarthritis. Some 438 patients awaiting TKR were randomized to a short waiting time (WT) group (<= 3 months) or a non-fixed WT group. In the final assessment, 310 patients (213 women) with a mean age of 68 years were included. HRQoL was measured on being placed on the waiting list and again at hospital admission using the generic 15D. Patients' self-report pain and physical function were evaluated using a scale modified from the Knee Society Clinical Rating System. The median WTs for patients with short and non-fixed WT were 73 days (range 8-600 days) and 266 days (range 28-818 days), respectively. At admission, as assessed by the intention-to-treat analysis, there were no statistically significant differences between the groups in the 15D total score and disease-specific pain and function. Our study showed that longer WT did not result in worse pre-operative HRQoL.