The effect of age on the quality of life after knee replacement

Two-hundred and twenty-one consecutive patients over 50 years old who had undergone unilateral total knee replacement for osteoarthritis had their Quality Adjusted Life Years (QALYs) assessed using the Rosser index. The patients were divided into four groups by age: 51–60 years old; 61–70 years old; 71–80 years old; and 81–90 years old. The main outcome measures were Quality-of-Life gain (QoL gain) and QALYs formed from the Rosser index, post-operative complications, Guepar and HLS knee scores and a subjective analysis of outcome. Results: The oldest group had a poorer pre-operative quality of life (QoL) scores but no difference in gain compared to the other groups. There was no difference in the post-operative complication rates, nor in the subjective outcomes. The gain in QALY was 1.94 (S.E.M.±0.81) for 51–60 years old, 1.76 (±0.35) for 61–70 years old, 1.16 (±0.11 for 71–80 years old and 1.02 (±0.18) for 81–90 years old. The improvement in knee scores did not correlate with QoL gain. It was concluded that age is not a determining factor in the outcome following total knee replacement (TKR). QALY is a crude measure of outcome from TKR whose mean value alters according to the age of the population studied, the precise indications for the operation and the length of time after the operation. The value of the QALY can therefore be manipulated up and down depending on the design of the study. QALY as an economic measure must be treated with caution. © 1997 Elsevier Science B.V.