A comparison of low back pain patients in the United States and New Zealand: psychosocial and economic factors affecting severity of disability.

One hundred and ninety-eight patients suffering from chronic low back pain seen at the University of Virginia (U.S.) Pain Center and 117 similar patients seen at the Auckland Hospital, Auckland, New Zealand (N.Z.) Pain Clinic completed a self-report questionnaire prior to beginning comparable outpatient treatment programs. Approximately 55% of the sample from each country returned a follow-up questionnaire 1 year later. Analyses of the results indicated that despite nearly similar between-country reports of pain frequency and intensity, the U.S. patients, both at pre- and post-testing, reported greater emotional and behavioral disruption as a correlate of their pain. U.S. patients consistently used more medication, experienced more disphoric mood states, and were more hampered in social-sexual, recreational, and vocational functioning. Patients from both countries demonstrated a nearly equal degree of pre- to post-improvement; however, the relative initial differences favoring the New Zealanders remained constant across both questionnaire administrations. At the onset of treatment, 49% of the U.S. sample and only 17% of the N.Z. patients were receiving pain-related financial compensation. At follow-up, patients from both countries receiving pretreatment compensation were less likely to report a return to full activity, although the relationship appeared more pronounced in U.S. patients. Seemingly, compared to the U.S., the N.Z. compensation-disability system is used less, or for shorter durations of time, resulting in less severe life-style disruption than appears to be the case in the U.S.