Screening for symptoms of depression by physical therapists managing low back pain

Background and Purpose. Depression is a condition that worsens the prognosis of low back pain (LBP) and is under-recognized and undertreated in primary care. The purpose of this study was to evaluate the accuracy with which physical therapists screen for depressive symptoms among their patients with LBP. Subjects. Sixty-eight physical therapists and 232 patients with nonspecific LBP from 40 physical therapy clinics participated. Methods. Patients completed the reference standard (Depression Anxiety Stress Scales [DASS]) and a 2-item screening test for depression taken from the Primary Care Evaluation of Mental Disorders Procedure (PRIME-MD). Treating physical therapists used a 0 to 10 scale to judge whether each patient was depressed. Based on the short form Depression Anxiety Stress Scales (DASS-21) depression scale score, each patient was categorized as exhibiting normal, mild, moderate, severe, or extremely severe depression symptoms, and receiver operating characteristic (ROC) curves were generated to describe test accuracy. Results. The 2-item screening test was more accurate in screening for depressive symptoms than the physical therapists' ratings were; for example, in detecting moderate depressive symptoms in the 2 areas under the ROC curve, values were 0.66 versus 0.79. Discussion and Conclusion. Because the therapists did not accurately identify symptoms of depression, even symptoms of severe depression, despite the common presentation in their clinics, we recommend that physical therapists managing patients with LBP use the 2-item depression screening test. Administration of this screening test would improve physical therapists' ability to screen for symptoms of depression and would enable referral for appropriate management.