Severity indices of personality problems–short form in old-age psychiatry: Reliability and validity

The Severity Indices of Personality Problems (SIPP; Verheul et al., 2008) is a popular self-report questionnaire that measures severity of maladaptive personality functioning. Two studies demonstrated the utility of the short form (SIPP–SF) among older adults but validation in clinical settings is lacking. Therefore, we examined the psychometric properties of the SIPP–SF in a large sample of older adult Dutch outpatients (N = 124; age range = 60–85 years, M = 69.8, SD = 5.3). The SIPP–SF domains showed good to excellent internal reliability (Cronbach’s α = .75–.91) and effectively discriminated between participants with and without a personality disorder, as assessed with the Structured Clinical Interview for DSM–IV Axis II Personality Disorders (SCID–II). Convergent validity of the SIPP–SF was examined with instruments for measuring personality pathology among older adults (Informant Personality questionnaire [HAP]; Gerontological Personality Disorders Scale [GPS]). The GPS generally correlated with the SIPP–SF domains in expected directions, with small to large effect sizes. For the HAP, only 1 scale correlated with all SIPP–SF domains. No associations were found between the SIPP–SF and psychiatric symptomatology as measured by the Brief Symptom Inventory (BSI). The SIPP–SF appears to be a promising instrument for assessing maladaptive personality functioning among older adult outpatients.