Patient-reported outcomes should not be sole measure of treatment efficacy
Patient-reported outcomes should not be the sole basis of intervention efficacy, a new prospective cohort study argues, citing as evidence the lack of correlation between patient-reported outcomes and objective functional assessments in total hip or knee arthroplasty (THA/TKA).
The study included 112 Danish THA or TKA patients (aged 55 to 80 years) who were made to accomplish the hip or knee injury and osteoarthritis outcome score (HOOS/KOOS). Objective functional measures were obtained using the paced-walk, chair-stand and stair-climb tests. The objective of the study was to examine the potential correlation between objective and self-reported functional measures.
In the study population, 60 were THA patients (mean age 67 years) and 52 were TKA patients (mean age 64 years). Improvements in physical function were reported by 58 and 73 percent of the THA and TKA patients, respectively, in the HOOS/KOOS at days 13 and 20.
Compared to baseline, both THA (mean difference [MD], 7 percent; 95 percent CI, 1 to 13 percent; p=0.033) and TKA (MD, 6 percent; 1 to 12 percent; p=0.033) patients reported significant improvements in physical function.
In contrast, the 40-metre paced-walk test reflected a decline in physical performance from baseline in THA patients until day 14 (MD, -6; -11 to -1; p=0.020) and TKA patients until day 21 (MD, -10; -13 to -6; p<0.001).
The 9-step stair climb test also showed similar trends for THA (MD, -8; -11 to -4; p<0.001) and TKA (MD, -4; -7 to -1; p=0.02) patients. No functional deterioration was detected from the chair-stand test.
There was no significant correlation between the objective measures of physical function and HOOS in THA (p=0.314) and KOOS in TKA (p=0.418) patients.