Reliability in Measuring Preinjury Physical Function in Orthopaedic Trauma.

Abstract

In orthopaedic trauma, patients' functional status scores cannot be collected before injury. Due to the lack of these data, it is difficult to reliably determine if patients have returned to their preinjury level of physical function. The goal of this article is to determine if patients' assessment of preinjury function agrees with that of familiar proxies, to determine whether patient assessment of preinjury function may be regarded as reliable. At first postinjury outpatient follow up, orthopaedic trauma patients and their proxies were asked to independently complete the PROMIS physical function computer adaptive test (PF CAT) based on how they perceived the function of the patient before injury. Intraclass correlation, paired sample t tests, and 95% confidence intervals were used to analyze patient-proxy agreement. Fifty patient-proxy pairs completed the questionnaire at an average of 14.3 (SD = 1.1) days postoperative (average 19.3, SD = 12.1 days postinjury). Patient mean PF CAT score was 57.92 (SD = 10.38) for patients and 56.59 (SD = 11.50) for proxies. Paired samples t test showed that patient's PF CAT scores were not significantly different from proxy scores [mean score difference = 1.33; 95% CI = (-1.28, 3.94); P = 0.311]. Intraclass correlation between patient and proxy scores was 0.79. There was no notable bias. Good agreement in PF CAT preinjury assessment between patients and proxies support patients' ability to report reliable preinjury physical functioning in the early postinjury setting using the PF CAT.