Validity of the Somatic Symptom Disorder-B Criteria Scale (SSD-12) in primary care.

Aim: The Somatic Symptom Disorder-B Criteria Scale (SSD-12) assesses the psychological features of DSM-5 somatic symptom disorder. The purpose of the current study was to investigate the psychometric characteristics and validity of the 12-item instrument to demonstrate its suitability in primary care. Method: The study was designed as a cross-sectional survey set in five primary care practices from Munich, Germany (n = 501, 52.0% female, mean age 47 ± 16 years). Item and scale characteristics, as well as measures of reliability and validity, were determined. Results: The SSD-12 has good item characteristics and excellent reliability (Cronbach's α = 0.92). Confirmatory factor analyses provided evidence to support a general factor model of the SSD-12 in primary care (comparative fit index > 0.98, Tucker-Lewis index > 0.98, root mean square error of approximation = 0.090, 90% confidence interval: 0.078-0.102). SSD-12 total sum-score was significantly associated with somatic symptom burden (r = 0.48, P < 0.001), general anxiety (r = 0.54, P < 0.001) and depressive symptoms (r = 0.60, P < 0.001). At the group level, SSD-12 scores could differentiate between different patient groups (e.g. with and without chronic illness). Conclusions: The SSD-12 appears to be a reliable, valid and time-efficient self-report measure of the psychological characteristics related to the experience of somatic symptoms which is suitable for primary care. Future research should evaluate its responsiveness to treatment and feasibility as a screening tool in different clinical settings.

Do general practice patients with and without appointment differ? Cross-sectional study.

BACKGROUND: Even in practices with a comprehensive appointment system a minority of patients walks in without prior notice, sometimes causing problems for practice service quality. We aimed to explore differences between patients consulting primary care practices with and without appointment. METHODS: Consecutive patients visiting five primary care practices without an appointment and following patients with an appointment were asked to fill in a four-page questionnaire addressing socio-demographic characteristics, the reason for encounter, urgency of seeing a physician, depressive, somatic and anxiety symptoms, personality traits, and satisfaction with the practice. Physicians also documented the reason for encounter and assessed the urgency. Data were analyzed using univariate and multivariate methods. RESULTS: Two hundred fifty-one patients without and 250 patients with appointment participated. Patients without appointment were significantly younger (mean age 44 vs. 50 years) and reported less often chronic diseases (29% vs. 45%). Also, reasons for encounter differed (e.g., 27% vs. 16% with a respiratory problem). Patients' ratings of urgency did not differ between groups (p = 0.46), but physicians rated urgency higher among patients without appointment (p < 0.001). In logistic regression analyses younger age, male gender, absence of chronic disease, positive screening for at least one mental disorder, low values on the personality trait openness for experience, a high urgency rating by the physician, and a respiratory or musculoskeletal problem as reason for encounter were significantly associated with a higher likelihood of being a patient without appointment. CONCLUSIONS: In this study, younger age and a high urgency rating by physicians were the variables most consistently associated with the likelihood of being a patient without appointment. Overall, differences between patients seeking general practices with a comprehensive appointment system without prior notice and patients with appointments were relatively minor.