Studies that assess the population requirement for treatment (i.e., the number of people who would benefit from evidence-based, effective treatment and would choose to accept such treatment) are rare because they are expensive and time consuming. We applied published estimates of the incident and prevalent requirement for total hip replacement in the United Kingdom1 to the 1996 Ontario population aged 35 to 85 years.2 We then compared this requirement with the actual provision of surgery, on the basis of data from the Canadian Institute for Health Information on hospital separations (procedure codes 93.51 and 93.59,3 excluding cases with a diagnosed fracture of the neck of the femur [code 820.0 of the International Classification of Diseases, 9th revision4]).
Given an incident requirement rate of 2.23 total hip replacements per 1000 people, we estimated that 12 088 people per year in Ontario require surgery for their hip pain. In 1996 the number of surgeries provided (6838) fell short of this estimate, by 43%. The prevalent requirement (i.e., the accumulated backlog of people requiring surgery) was much higher: 82 362 people.
Although this analysis has limitations, we believe that the approach is justified because the prevalence of self-reported hip pain is broadly similar in Canada and the United Kingdom1,5 and because the age distribution of the 2 populations is similar. We were unable to compare our estimates with the findings of an Ontario study6 because the researchers in that study combined hip and knee arthroplasty into one category and did not distinguish between prevalent and incident requirements.
Measuring the gap between the population requirement for health services and the provision of these services may be a useful way of identifying shortcomings in the delivery of care. Our results suggest that many people in Ontario who experience severe hip pain are not receiving beneficial treatment.