Time for a paradigm shift with computerized adaptive testing of general physical function outcomes measurements

Area of Science:

• Orthopedics
• Biostatistics
• Health Outcomes Research

Background:

• Patient-reported outcomes (PROs) are essential for evaluating orthopedic treatments.
• Current generic instruments may not adequately assess physical function in foot and ankle patients.

Purpose of the Study:

• To compare the psychometric properties of the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) Computerized Adaptive Test (CAT) and Lower Extremity (LE) CAT against the SF-36 PF in foot and ankle patients.

Main Methods:

• A cohort of 126 foot and ankle patients was assessed using the SF-36 PF, PROMIS PF CAT, and LE CAT.
• Rasch item response theory (IRT) modeling was employed to evaluate fit, dimensionality, reliability, validity, and coverage.

Main Results:

• PROMIS PF CAT (3.9% unexplained variance) and LE CAT (2.1%) showed better psychometric properties than SF-36 PF (7.6%).
• PF CAT and LE CAT exhibited no significant floor or ceiling effects, unlike the SF-36 PF which had notable floor (11.1%) and ceiling (9.5%) effects.

Conclusions:

• PROMIS PF CAT and LE CAT are recommended over SF-36 PF for assessing patient-perceived functional outcomes in foot and ankle care.
• Further research comparing CATs to condition-specific instruments is warranted.