Linking Patient-Reported Outcome Measure Scores to Adverse Event Data to Gain Insight into Overestimation of Postoperative Patient-Reported Outcome Measure Improvement After Total Hip Arthroplasty and Total Knee Arthroplasty Due to Selective Nonresponse.

BACKGROUND

The purpose of the study was to gain insight into how clinically relevant improvement in patient-reported outcome measure scores after total hip arthroplasty (THA) and total knee arthroplasty (TKA) may be underestimated or overestimated, we compared patient-reported outcome measure respondents and nonrespondents on their adverse event rates and assessed whether adverse event occurrence was associated with clinically relevant patient-reported outcome measure improvement from those without adverse events.

METHODS

All primary THAs and TKAs performed in 19 Dutch hospitals between January 2017 and December 2019 were included. The hip disability and osteoarthritis outcome score-physical function short form (HOOS-PS) and knee injury and osteoarthritis outcome score-physical function short form (KOOS-PS) were used to assess the physical function after THA and TKA, respectively. Adverse events included 1-year revision, 30-day readmission, 30-day complications, and long (ie, >75th percentile) length of stay. A clinically relevant improvement was defined as at least a 10-point decrease in HOOS-PS and 9 points in KOOS-PS scores. Associations between adverse events and clinically relevant HOOS-PS and KOOS-PS improvement were assessed using binary logistic regression models adjusted for patient characteristics and clustering of patients within hospitals.

RESULTS

There were 20,338 THA and 18,082 TKA procedures included. Adverse events occurred more frequently in HOOS-PS and KOOS-PS nonrespondents than in respondents. The THA patients experiencing revision, complications, or long length of stay were less likely to experience clinically relevant HOOS-PS improvements (odds ratios of 0.11 [0.06 to 0.20], 0.44 [0.30 to 0.63], and 0.66 [0.50 to 0.88], respectively). The TKA patients experiencing revision or long length of stay were less likely to experience clinically relevant KOOS-PS improvements (odds ratios of 0.26 [0.12 to 0.55] and 0.63 [0.50 to 0.80], respectively).

CONCLUSIONS

Clinically relevant HOOS-PS and KOOS-PS improvements are likely overestimated, as nonrespondents had higher adverse event rates which were associated with lower likelihood to achieve clinically relevant HOOS-PS and KOOS-PS improvements.