Patient Acceptable Symptom State versus Latent Class Analysis Outcome Classification: A Comparative Longitudinal Study of Knee Arthroplasty.

When used for outcome classification, observed PASS scores consistently underperform relative to probabilistic latent class-derived subgroups of pain and self-rated health outcome. PASS is a weak substitute for probabilistic classification of other PROMs of KA outcome. Clinicians and researchers should rely on latent class analyses over PASS to differentiate between outcome subgroups following KA.