Do Randomized Controlled Study Patients Resemble Actual Patients?

Are the people who take part in randomized controlled trials (RCTs) in the total joint arthroplasty (TJA) realm truly representative of those who undergo TJA?

This was the question that a team from Weill Cornell Medicine and Hospital for Special Surgery in New York recently tackled in their work, “Characterization and Potential Relevance of Randomized Controlled Trial Patient Populations in Total Joint Arthroplasty in the United States: A Systematic Review,” published in the June 20, 2022 edition of The Journal of Arthroplasty.

“A substantial number of RCT studies in total joint arthroplasty (TJA) are published each year,” said co-author Jonathan S. Yu, a medical student at Weill Cornell. “However, it was unknown how closely the demographic characteristics of TJA RCT cohorts resemble that of the U.S. patient population undergoing TJA. We felt that an assessment of this cohort could be helpful for future RCTs.”

Using the Cochrane Central Register of Controlled Trials, the researchers investigated only RCTs published in 2018 or later (U.S. only). They included 153 RCTs in the systematic review.

The breakdown was as follows: 98 TKA-only studies, 33 THA-only studies, and 22 TKA and THA studies. The total number of patients in the 153 RCTs was 24,135 patients (13,298 in TKA-only studies and 4,589 in THA-only studies).

The investigators aggregated patient demographics and then compared them against demographics characteristics from the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality National Inpatient Sample and American College of Surgeons National Surgical Quality Improvement Program patient cohorts.

The demographics included in the study were sample size, age, sex, body mass index, ethnicity, smoking, diabetes mellitus, Charlson Comorbidity Index, work status, income, living alone, dependence on others, and caregiver.

Clinical care not at risk?

The team found that the average age of patients in the TJA RCT group was 65 years (53-80) while the National Inpatient Sample group was 67 years (18-90). The average body mass index of the TJA RCT cohort was 30.8 (18.2-37.6) while the National Surgical Quality Improvement Program cohort was 31.9 (14.1-59.6).

“Overall,” stated Jonathan Yu to OTW, “the U.S. RCT patient cohort for TJA does not differ substantially from the general patient population undergoing TJA in the United States. Differences in demographic and clinical characteristics between the TJA RCT cohort and database cohorts ranged from minimal to small, suggesting that these differences are unlikely to impact clinical outcomes.”