Assessing non-specific symptoms in epidemiological studies: Development and validation of the Symptoms and Perceptions (SaP) questionnaire

The SaP questionnaire is a reliable and valid self-reported measure of diverse features of NSS and corresponding perceptions. It can also be a useful tool for the identification of multiple somatic symptoms and related disorders in general practice and assessment of psychological problems in epidemiological studies. Further validation of the questionnaire in different samples and settings will establish the promising psychometric properties demonstrated in the present study.