Referral source and outcomes of physical therapy care in patients with low back pain.

STUDY DESIGN

Retrospective longitudinal cohort.

OBJECTIVES

To describe the clinical characteristics of patients with low back pain according to physician referral source, and to identify associations between referral source and discharge functional status, as well as number of physical therapy visits.

BACKGROUND

Little is known about associations between physician referral source and outcomes of physical therapy care for patients with low back pain. Exploring these associations can contribute to better understanding of physician-physical therapist relationships and may lead to improved referral patterns.

METHODS

Data from a proprietary clinical database were examined retrospectively. Physician referral source was classified as primary care, specialist, or occupational medicine. Outcomes were overall health status at discharge and number of physical therapy visits. Descriptive statistics and bivariate associations between referral source and each outcome were assessed by calculating differences and 95% confidence intervals (CIs) in means and proportions. To account for potential confounding, multilevel linear regression was used to adjust for baseline clinical covariates, effects related to clustering of patients treated by individual clinicians, and clinicians working within individual clinics.

RESULTS

Bivariate and multilevel analyses revealed significant associations between referral source and discharge overall health status, as well as number of visits. After multilevel adjustment for covariate and clustering effects, primary care and occupational medicine referrals were associated, on average, with point increases of 1.6 (95% CI: 0.7, 2.6) and 4.8 (95% CI: 2.7, 6.9) in discharge overall health status scores, respectively, compared to specialist referral. Similarly, primary care and occupational medicine referrals were associated, on average, with 0.44 (95% CI: 0.27, 0.61) and 0.83 (95% CI: 0.44, 1.22) fewer visits, respectively, compared to specialist referral.

CONCLUSION

After accounting for clinical covariates and clustering, patients with low back pain who were referred by occupational medicine and primary care physicians tended to have better functional outcomes and required fewer physical therapy visits per episode of care.

LEVEL OF EVIDENCE

Prognosis, level 2c.