Abstract
Background
Pain with radiation to the leg is a common presentation in back pain patients. Radiating leg pain is either referred pain or radicular, commonly described as sciatica. Clinically distinguishing between these types of leg pain is recognized as difficult but important for management purposes. The aim of this study was to investigate inter-therapist agreement when diagnosing referred or radicular pain.
Methods
Thirty-six primary care consulters with low back-related leg pain were assessed and diagnosed as referred or radicular leg pain by one of six trained experienced musculoskeletal physiotherapists. Assessments were videoed, excluding any diagnosis discourse, and viewed by a second physiotherapist who made an independent diagnosis. Therapists rated their confidence with diagnosis and reasons for their decision. Data was summarized using percentage agreements and kappa (K) coefficients with two sided 95% confidence intervals (CI).
Results
The therapists assessing and therapists watching the video both diagnosed radicular pain in 25 of the 36 patients. Agreement was 72% with fair inter-rater reliability (K = 0.35, 95% CI 0.07, 0.63, p<0.05). Mean confidence in diagnosis was 87% for radicular pain and 83% for referred pain. In the subgroup of patients where therapists' confidence in diagnosis was ≥ 80% (n=28), agreement was 86% with substantial reliability (K = 0.65, 95% CI 0.37, 0.93 p<0.001).
Conclusion
Reliability was fair among therapists when diagnosing back-related leg pain. This concurs with current opinion that differentiating between types of back-related leg pain can be difficult. However, when confidence in clinical diagnosis is high, levels of agreement and reliability indices improve substantially.
