Ratios: a) age ≥ 60 to age 50–59 surgery rates (left) and b) propensity for surgery at age > 62 relative to age ≤62 rate (right). * Rates in public hospitals in England, adjusting for gender, ward ethnic mix and deprivation, distance to and characteristics of hospitals . ** Rate of receipt of primary surgery after five years, based on population samples from two areas of Ontario, Canada. Relative to age ≤ 62. Adjusting for WOMAC, SF-36 General Health, Willingness to undergo surgery .