In five countries during a 10-year period, there have been statistically significant increases in the lifetime risk for total hip replacement surgery for osteoarthritis, as well as significant differences between sexes, according to results presented at the American College of Rheumatology Annual Meeting in San Diego.
In the multinational, population-level study, researchers evaluated observational data from national arthroplasty registries in five countries — Australia, Denmark, Finland, Norway and Sweden.
The researchers collected arthroplasty registry data, life table data and population data. Information on all primary total hip replacement (THR) procedures performed for OA between 2003 and 2013 was acquired.
The researchers computed the lifetime risk for THR in 2003 and 2013. Separate calculations were made for women and men.
They found that, in 2003, women had a lifetime risk for THR ranging from 8.7% in Denmark to 15.9% in Norway. For men, the lifetime risk in 2003 ranged from 6.3% in Denmark to 8.6% in Finland. There was a significant increase in both sexes between 2003 and 2013 in lifetime risk for THR in all countries, women in Norway were an exception; their lifetime risk was high at both time points.
Female patients had a consistently higher lifetime risk for surgery in all five countries. This pattern was especially prominent in Norway, where women in 2003 had a lifetime THR risk (15.9%; 95% CI, 15.6-16) that was more than twice that of their male counterparts (6.9%; 95% CI, 6.7-7.1).
In 2013, lifetime risk for women was at its lowest in Denmark and at its highest in Norway. For men, the lowest lifetime THR risk was seen in Norway and the highest risk was seen in Finland.
As was the case in 2003, women in 2013 showed a higher lifetime risk for THR vs. men in all countries. Again, the most significant between-sex difference in lifetime risk was in Norway, where the risk in 2013 for women was almost double that of men (women, 16%; 95% CI, 15.8-16.3; men, 8.3%; 95% CI. 8.1-8.5).
In 2013, as many as 1 in 7 women in Norway and 1 in 10 men in Finland had high lifetime risk for THR.
Except in Norway, where the lifetime THR risk was consistently high throughout, each country showed a significant increase in lifetime risk for THR for women over time. Women in Australia demonstrated the greatest absolute increase in lifetime risk during the 10-year period (increase of 3.4%), followed by women in Denmark (increase of 3%).
Men likewise showed a significant increase in lifetime risk for THR over time. The greatest absolute increases occurred in Australia (increase of 2.9%) and Denmark (increase of 2.7%). In a sensitivity analysis factoring in both THR and hip resurfacing surgery, similar results were seen in terms of between-country variation and increases in lifetime risk during the study interval.
With the exception of women in Norway, both sexes in all countries showed an overall increase in THR over time. The highest rates of THR in both sexes at both time points were seen in patients aged 70 to 79 years. Across the countries, the highest rate of THR was seen in women aged 70 to 79 years in Finland, with 1,081 procedures documented per 100,000 population in 2014. Compared with the THR rate in similarly aged women in Australia, Denmark and Sweden in 2013, the rate of women in Norway was more than 1.5 times higher.
In both 2003 and 2013, women in Norway aged 60 to 69 years and women aged at least 80 years had higher rates of THR vs. women in the other countries. Patients aged 50 years or younger had persistently low THR rates in all countries.
“This study has identified significant increases in the lifetime risk of THR for OA in five high-income countries over a 10-year period,” the researchers wrote. “These data allow us to better comprehend the changing burden of advanced hip OA and its surgical management at an international level, and can be used to inform the planning of health service delivery to meet growing population demand.” – by Jennifer Byrne
Disclosures: Ackerman reports her work was supported by a National Health and Medical Research Council of Australia Public Health Early Career Fellowship (#520004). Please see the study for all other authors’ relevant financial disclosures.