Characteristics of chest wall injuries that predict postrecovery pulmonary symptoms: A secondary analysis of data from a randomized trial

BACKGROUND Although thoracic trauma is common, little is known about which factors lead to poor functional outcomes. We sought to determine which characteristics of chest wall injury predict postrecovery pulmonary symptoms or health-related quality of life. METHODS We conducted a secondary analysis of data from a randomized trial involving patients with chest wall injuries at a Level I trauma center between December 2007 and July 2012. We evaluated the overall severity of the chest wall injurycharacterized primarily by the number of fractured ribsand rib fracture location (upper, middle, and lower; anterior, lateral, and posterior) as predictors of patient-reported outcomes 60 days after injury: dyspnea burden (0-40), Modified Medical Research Council Dyspnea Scale (MMRC) (0-4), St. George's Respiratory Questionnaire (SGRQ), and normalized Medical Outcomes Study Short-Form 36 (SF-36) scores. RESULTS Of 189 evaluable subjects, the mean (SD) number of fractured ribs was 5 (4). The number of fractured ribs was not associated with dyspnea burden, MMRC, or SGRQ scores. After adjustment for confounders, each additional fractured rib was associated with worse SF-36 Physical Functioning and Bodily Pain scores (-0.6 units [95% confidence interval (CI), -1.1 to 0.0] and -0.8 units [95% CI, -1.3 to -0.2], respectively). Lower rib fractures were associated with worse dyspnea burden (3.4 units; 95% CI, 1.0-5.9), MMRC score (0.4 units; 95% CI, 0.0-0.8), and SF-36 Physical Functioning, Role-Physical, Role-Emotional, and Physical Component Summary scores (-4 units [95% CI, -8 to 0], -5 units [95% CI, -8 to -1], -4 units [95% CI, -8 to 0], and -4 units [95% CI, -7 to -1], respectively). CONCLUSION The overall anatomic severity of chest wall injuries does not predict worse dyspnea symptoms 60 days after injury, but it does predict increased patient perceptions of pain and physical function limitations. Lower rib fractures predict both persistent respiratory symptoms and perception of decreased overall health. LEVEL OF EVIDENCE Prognostic/epidemiologic study, level III.