Determinants of disability after lower extremity fracture

Background: Factors influencing the progression of physical impairment to p atient-perceived disability are not well known, We sought to better underst and this relationship in the setting of injury, Methods: We followed a cohort of 302 patients with lower extremity fracture s over a I-year period. Physical impairment was assessed by range of motion , strength, and pain. Range of motion and strength were assessed together a s a proportion of normal function of the extremity; (impairment score). Pai n was assessed using a Visual Analogue Scale (VAS) pain score. Disability w as assessed using the Sickness Impact Profile (SIP), a widely used measure of patient-perceived limitations of everyday activities attributable to ill ness. The SIP was administered during hospitalization to assess preinjury b ase-line. Impairment assessment and readministration of the SIP were perfor med at 12 months after injury. Results: Impairment in leg: function (range of motion and strength) was hig hly correlated (p < 0.001) with overall SIP score at 12 months, but account ed for only 23% of the variance in overall SIP scores, Likewise, VAS pain s core was highly correlated (p < 0.001) with overall SIP score at 12 months, but accounted for only 29% of the variance in overall SIP scores. In a mul tivariate linear regression analysis, variables that were independently ass ociated with overall SIP score included impairment score, VAS pain score, p reinjury SIP, poverty status, education status, social support, having hire d a lawyer, and involvement with workers' compensation. These variables acc ounted for 52% of the variance in overall SIP scores at 12 months, Conclusion: The degree of physical impairment accounts for only a small amo unt of the variance in disability from lower extremity fracture. Identifiab le patient characteristics including age, socioeconomic status, preinjury h ealth, and social support together with impairment account for over half of the variance in long-term disability. Further research is needed to increa se understanding of other factors that influence the progression of impairm ent to disability, especially those factors that may be amenable to interve ntion.