Validation of PROMIS Physical Function Instruments in Patients With an Orthopaedic Trauma to a Lower Extremity

Abstract

Objectives: To evaluate the reliability, convergent validity, known-groups validity, and responsiveness of the Patient-Reported Outcomes Measurement Information System (PROMIS) Mobility Computer Adaptive Test (CAT) and PROMIS Physical Function 8a Short Form. Design: Prospective cohort study. Setting: Two Level-I trauma centers. Patients: Eligible adults with an isolated lower extremity trauma injury receiving treatment were approached consecutively (n = 402 consented at time 1, median = 80 days after treatment). After 6 months, 122 (30.3%) completed another assessment. Intervention: Cross-sectional and longitudinal monitoring of patients. Main Outcome Measurements: Floor and ceiling effects, reliability (marginal reliability and Cronbach's alpha), convergent validity, known-groups discriminant validity (weight-bearing status and fracture severity), and responsiveness (Cohen's d effect size) were evaluated for the PROMIS Mobility CAT, PROMIS Physical Function 8a Short Form, and 5 other measures of physical function. Results: PROMIS PFSF8a and Foot and Ankle Ability Measure Activities of Daily Living Index had ceiling effects. Both PROMIS measures demonstrated excellent internal consistency reliability (mean marginal reliability 0.94 and 0.96; Cronbach's alpha = 0.96). Convergent validity was supported by high correlations with other measures of physical function (r = 0.70–0.87). Known-groups validity by weight-bearing status and fracture severity was supported as was responsiveness (Mobility CAT effect size = 0.81; Physical Function Short Form 8a = 0.88). Conclusions: The PROMIS Mobility CAT and Physical Function 8a Short Form demonstrated reliability, convergent and known-groups discriminant validity, and responsiveness in a sample of patients with a lower extremity orthopaedic trauma injury.

The expansion and validation of a new upper extremity item bank for the Patient-Reported Outcomes Measurement Information System® (PROMIS)

“…Finally, convergent validity between the UE v2.0 item bank was evaluated. Previous studies have found that PROMIS PF measures highly correlate with non-PROMIS measures (generally r > 0.80) [16, 18, 24, 25]. In the full bank dataset, the Flexilevel Scale of Shoulder Function Short Form (FLEX-SF) [34] and PROMIS PF v2.0 Short Form 8b (PFSF8b) were co-administered with the candidate UE item bank.…”

“…Recent studies have evaluated the comparability for Mobility items and UE items in relation to overall PROMIS-PF. Scores were exchangeable in a sample of lower extremity trauma patients (correlation between Mobility-CAT and the 8-item short form [PFSF8a v1.0] was 0.91; mean difference approximately 1 T-score [24]). Scores were not exchangeable for other populations, including upper extremity trauma patients (correlations have ranged from 0.64 to 0.87 between the UE v1.0–v1.2 and PF scores [18, 19, 25]; with a mean score difference of approximately 8 T-score points favoring better outcomes on the PFSF8a than the UE-CAT for trauma patients [25]).…”

Preoperative Evaluation of the Lower Extremity-Specific PROMIS Mobility Bank in Patients with ACL Tears

“…19 This suggests convergent validity and is consistent with previously published studies of patients with lower extremity fractures and multiligamentous knee injuries. 16,17 PROMIS Mobility correlated to a lesser extent with SANE and PROMIS PI scores, an expected finding that suggests divergent validity. Additionally, the test burden of the PROMIS Mobility instrument was low, with patients answering a mean of 4.7 items, comparatively fewer than the 19 items (10 questions with 1 question having 9 and 1 having 2 subsections, respectively) required to complete the IKDC.…”

“…Our findings also suggest that PROMIS Mobility is by traditional definitions inclusive in preoperative patients with ACL tears, because there were no floor or ceiling effects meeting the !15% conventional threshold of significance, consistent with other recently published studies. 16,17 In this study, we used an injured preoperative cohort of patients who are expected to return to a higher level of functioning after surgery. As such, the potential exists for ceiling effects at postoperative follow-up time points.…”

Content Validity of the LIMB-Q: A Patient-Reported Outcome Instrument for Lower Extremity Trauma Patients

“…As a result, it is not clear if these instruments evaluate all relevant concepts of interest (COI) to lower extremity trauma patients who undergo either reconstruction or amputation. 8,10,11 Therefore, while previous studies evaluating outcomes in this patient population have been rigorous and well designed, it is not clear if the outcomes measured reflect what is actually important to these patients.…”