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 (= 124; age range = 60-85 years,  = 69.8,  = 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.