[Validity of the hospital anxiety and depression scale in patients with chronic pain.].

BACKGROUND AND OBJECTIVES Several studies suggest a strong association between anxiety and depression with chronic pain. That can be demonstrated using standard scales to detect these symptoms. The objective of this study was to determine sensibility and specificity of the Hospital Anxiety and Depression Scale (HAD) in patients with chronic pain syndromes followed at the Pain Center of the Hospital Universitário Professor Edgard Santos. METHODS A transversal, descriptive study was conducted with patients who sought to the Pain Center between March 2002 and July 2003. It was composed of interviews using the HAD Scale and the M.I.N.I. International Neuropsychiatric Interview Brazilian Version 5.0.0 (M.I.N.I. PLUS). RESULTS Ninety-one patients were evaluated. The HAD demonstrated that 61 patients (67%) presented anxiety, while 42 patients (46.2%) presented depression. HAD results showed that among patients with depression, 38 (90.5%) also had anxiety; while among those with anxiety, 38 (62.3%) also had depression. Statistical analysis showed that this association was statistically significant (p < 0.001). M.I.N.I. PLUS revealed an incidence of 40.7% in current mood changes and 47.3% of anxiety. As for HAD's sensibility and specificity, we found the following results: sensibility of 73.3% for depression and 91.7% for anxiety, and a specificity of 67.2% for depression and 41.8% for anxiety. CONCLUSIONS The HAD scale showed good sensibility to evaluate anxiety and depression symptoms, but did not demonstrate good specificity for the diagnosis of depression and anxiety.