THE DOMINANT ROLE OF PSYCHOSOCIAL RISK-FACTORS IN THE DEVELOPMENT OF CHRONIC LOW-BACK-PAIN DISABILITY

Study Design. An inception cohort design was used in which 421 patient s were evaluated systematically with a standard battery of psychosocia l assessment tests (Structured Interview for DSM-III-R Diagnosis, Minn esota Multiphasic Personality Inventory, and Million Visual Pain Analo g Scale) within 6 weeks of acute back pain onset. Objectives. The pres ent study evaluated the predictive power of a comprehensive assessment of psychosocial and personality factors in identifying acute low back pain patients who subsequently develop chronic pain disability proble ms (as measured by job-work status at 1-year follow-up evaluation). Su mmary of Background Data. There has been a relative paucity of prospec tive research in the United States comprehensively evaluating potentia l psychosocial risk factors that are associated with those injured wor kers who subsequently fail to return to work and productivity after 1 year because of low back pain disability. Such research has been quite limited bacause of the time and cost involved in conducting prospecti ve studies. Methods. All study patients were symptomatic with lumbar p ain syndrome for no more than 6 weeks. These acute patients were track ed every 3 months, culminating in a structured telephone interview bei ng conducted 1 year after the initial evaluation to document return-to -work status. Results. Logistic regression analyses, conducted to diff erentiate between patients who were back at work after 1 year versus p atients who were not because of the original back injury, revealed the importance of three psychosocial measures: self-reported pain and dis ability, scores on Scale 3 of the Minnesota Multiphasic Personality In ventory, and workers' compensation and personal injury insurance statu s. The model generated correctly classified 90.7% of the cases. Result s revealed that major psychopathology, such as depression and substanc e abuse, did not precede or cause the development of chronic pain disa bility. Conclusions. These results show the presence of a robust ''psy chosocial disability factor'' that is associated with those injured wo rkers who are likely to develop chronic low back pain disability probl ems. Based on these data, a statistical algorithm has been generated t hat can identify those acute patients who will require early intervent ion to prevent the development of chronic disability. The second major result is that preinjury or concomitant psychopathology does not appe ar to predispose patients to chronic pain disability, although high ra tes of psychopathology have been shown in chronic low back pain. Futur e research should be directed at emotional vulnerability and psychosoc ial events in the period after the injury that may lead to chronicity.