Validation of the Spanish version of the Screening for Somatoform Symptoms-2 scale for use in Primary Care

Abstract

Objective: To study the diagnostic validity and to provide the sensitivity, specificity, positive predictive value and negative predictive value of the Spanish version of the Screening for Somatoform Symptoms-2 (SOMS-2) scale in a PC population sample. Design: Validation study. Setting: PC centres in Aragon and Balearic Islands, Spain. Participants: A sample of 109 patients from a clinical trial with somatoform disorders and 56 patients without somatoform disorder were included for the scale validation. Main outcome measures: Sensitivity, specificity, positive predictive value, negative predictive value and Cronbach's alpha coefficient. Results: Of the total,sample of 165 subjects, 75% were women and 60% had a diagnosis of somatization disorder and/or anxiety or depressive disorder. The 53-item version of the SOMS-2 with a cut-off point of 4 showed a sensitivity of 97%, a specificity of 68%, a positive predictive value of 85%, a negative predictive value of 92%, and high internal consistency (Cronbach alpha = 0.926). Conclusions: The Spanish version of the SOMS-2 seems to be a reliable screening tool, easy to complete and useful for the assessment of somatoform disorders in PC settings. The results for specificity, sensitivity, and internal consistency are similar to previous studies in other European languages.