4 Validation of PROMIS-29 Among Adult Burn Survivors

Abstract

Abstract Introduction Patient-reported outcomes are important for burn injury research and clinical practice. The PROMIS-29 profile has been validated for use in diverse populations and numerous conditions, though not among people living with burn injuries. The purpose of this study was to examine validity and reliability of PROMIS-29 scores in adults with burn injury. Methods Data were provided by adult burn survivors participating in a multi-center longitudinal study of outcomes after burn injury. The PROMIS-29 Profile, which includes 4 items for each domain of physical function, anxiety, depression, fatigue, sleep disturbance, ability to participate in social roles, and pain interference, was evaluated for validity and reliability. Floor and ceiling effects, unidimensionality, internal consistency, and reliability were examined. Differential item functioning (DIF) with respect to age, sex, education, race, ethnicity and burn size was assessed using ordinal logistic regression models and McFadden’s pseudo R2-change of ≥2% as critical value. Correlations with other measures (Community Integration Questionnaire, Satisfaction with Life Scale, Post-Traumatic Stress Checklist-Civilian, and Veteran’s Rand-12) and known group differences were examined to assess validity. Results 876 burn survivors with moderate to severe injury from 6 months-20 years post burn provided responses on PROMIS-29 domains. Participant ages ranged from 18–93 years at time of assessment; mean years since injury was 3.4. All PROMIS-29 domains showed high internal consistency (Cronbach’s α=0.87–0.97). Substantial portions of the sample reported no symptoms (anxiety [42.6%], depression [50.9%], fatigue [26.3%], pain [47.7%]). There was a large ceiling effect on social roles (39.7%) and physical function (43.3%). One-factor confirmatory factor analyses supported unidimensionality for all domains (all CFI >0.95). We found no bias (DIF) across any demographic or clinical groups. Reliability was high (>0.9) across trait levels for all domains except sleep, which reached moderate reliability (>0.85). Known-group differences by demographic and clinical characteristics performed as hypothesized except burn size categories, which showed no significant relationship with PROMIS-29 physical function, fatigue, and pain interference scores. Conclusions The results provide strong evidence of reliability and validity of PROMIS-29 scores among adult burn survivors. Reliability of the extreme scores can potentially be increased and the ceiling effects reduced by administering PROMIS-43, which includes 6 items per domain.