Are THA Patients Getting Younger? (AAOS 2014 Annual Meeting News)
A study presented yesterday by Jacob M. Drew, MD, suggests that a significant shift is occurring toward younger patients undergoing total hip arthroplasty (THA). In fact, between 2000 and 2009, the number of patients ages 45 years to 64 years who underwent THA increased by 123 percent.
“The trend of increasing incidence of THA, particularly among younger patients, should be studied and understood to guide consensus strategy and maximize efficiency of resources related to THA,” stated Dr. Drew.
In this study, researchers from the University of Massachusetts Medical School addressed how population size affected the overall increase in THA, the secondary effects of a shift to a younger patient population, and the impact on revision burden.
Assessing the data
Dr. Drew and his fellow investigators performed this retrospective review by analyzing data from 2000 to 2009 as recorded in the Nationwide Inpatient Sample, part of the family of software tools and databases developed for the Healthcare Cost and Utilization Project. The researchers identified all patients who had undergone THA or revision THA.
Using national weighted estimates and standard statistical analyses, Dr. Drew and his colleagues assessed the following patient factors for each year, stratified by age: procedural rates; gender; race; payer; length of stay (LOS); discharge disposition; revision burden.
Then, they used data from the U.S. National Census and Intercensus Estimates to calculate the rate of each procedure per 100,000 members of the U.S. population in each age group per year.
Evaluating the results
In total, researchers analyzed data related to more than one million patients. They found that the number of THAs performed between 2000 and 2009 increased by 73 percent overall. Specifically, among those ages 45 years to 64 years, the number of THA procedures increased by 123 percent, rising from 51,818 THAs in 2000 to 115,593 THAs in 2009.
Among individuals aged 65 years to 84 years, the number of THA procedures increased by 54 percent, rising from 91,541 procedures in 2000 to 141,164 procedures in 2009. “Increased incidence of THA in younger patients is driven primarily by increased per capita rates,” said Dr. Drew.
In addition, noted Dr. Drew, “the number of revision THAs per year increased by 27 percent overall, while the rate of revision THAs increased by 8 percent.” He also noted that the revision burden decreased from 17.7 percent to 13.7 percent overall.
Among those in the 45–64 age group, the revision burden decreased from 15.2 percent to 11.6 percent. “Despite spanning the peak of the metal-on-metal era, the decade saw a decrease in the overall revision burden by 23 percent,” said Dr. Drew, “including a 24 percent decrease in the 45–64 age group. These developments may be explained by improvements in technique, materials (cross-linked polyethylene), and implant design.”
The findings indicate a trend toward fewer THAs paid by Medicare (58.2 percent in 2000 to 52.8 percent in 2009), while more THAs were covered by private insurance over the course of the study period (36.1 percent in 2000 to 40.5 percent in 2009). LOS, however, decreased overall, and was similar among both younger and older patients.
“The trend toward greater use of THA is highlighted by increasing proportions of younger patients undergoing THA,” noted Dr. Drew. These younger patients may have the same level of pain and physical disability as older patients, according to data from FORCE-TJR, a nationwide comprehensive database of total joint arthroplasty surgical and patient-reported outcomes based at the University of Massachusetts Medical School, funded by the Agency for Healthcare Research & Quality.
The authors of Scientific Paper 542, “Trends in Total Hip Arthroplasty in the United States: The Shift to a Younger Demographic,” include Dr. Drew and Jeffrey K. Lange, MD; Virginia Briggs, PhD; Patricia Franklin, MD, MBA, MPH; and David C. Ayers, MD. Details of the authors’ disclosures as submitted to the Orthopaedic Disclosure Program can be found in the Final Program; the most current disclosure information may be accessed electronically at www.aaos.org/disclosure
2014 Annual Meeting News
Tuesday through Friday, March 11 – 14, 2014.
http://www.aaos.org/news/acadnews/2014/AAOS15_3_14.asp