Investigating the Psychometric Properties of the 8-Item Somatic Symptom Scale in Non-clinical Sample of Iranian People

Somatic Symptom Disorder (SSD) refers to one or more symptoms that cause distress or a significant disruption in one’s daily life and is correlated with poor Quality of Life and psychological distress, as well as an increased burden on health services. Therefore, its identification and treatment are of great importance because of the high prevalence and cost of this syndrome. The present study aimed to evaluate the factor structure, as well as the validity and reliability of the 8-Item somatic symptom scale (SSS-8) in a non-clinical sample of Iranian society.

The study participants included 281 individuals, who referred to Taleghani Hospital as the patients’ companions. After obtaining their informed consent, the participants answered Beck anxiety inventory, general health, SSS-8, and somatic symptoms 12 questionnaires. After completing the questionnaires, the collected data were analyzed by SPSS v. 24 and LISREL software.

Confirmatory factor analysis indicated that gastrointestinal problems, pain, fatigue, and cardiopulmonary complaints were the general factor loadings of somatic symptoms. Besides, the 8-item Somatic Symptom Scale had good internal consistency. Regarding validity, the 8-question scale showed a positive correlation with the Beck anxiety inventory (r=0.70), general health questionnaire (r=0.70) and, somatic symptoms 12 (r=0.52).

The findings provided preliminary support for the validity and reliability of the scores derived from the 8-item Somatic Symptom Scale. This scale can be used to evaluate the severity of somatic symptoms of patients referring to health clinics. Additionally, it is beneficial for interested researchers to investigate this disorder and its complications.