Supplementary materials to: A self-report measure of perfectionism: A confirmatory factor analysis of the Swedish version of the clinical perfectionism questionnaire

Background: Perfectionism is often defined as the strive for achievement and high standards, but can also lead to negative consequences. In addition to affecting performance and interpersonal relationships, perfectionism can result in mental distress. A number of different self-report measures have been put forward to assess perfectionism. Specifically intended for clinical practice and research, the Clinical Perfectionism Questionnaire (CPQ) was developed and is presently available in English and Persian. To promote its use in additional contexts, the current study has translated and investigated the psychometric properties of the Swedish version of the CPQ. Method: A Confirmatory Factor Analysis was performed to examine the best fit with data, using a priori-models and a sample of treatment-seeking participants screened for eligibility to receive Internet-based cognitive behavior therapy (n = 223). Results: The results indicated a lack of fit with data. A two-factor structure without the two reversed items (2 and 8) exhibited the best fit, perfectionistic strivings and perfectionistic concerns, but still had poor structural validity. Correlations with self-report measures of perfectionism, depression, anxiety, dysfunctional beliefs, self-criticism, quality of life, and self-compassion were all in the expected directions. Eight-week test-retest correlation was Pearson r = .62, 95% Confidence Interval [.45, .74], using data from 72 participants in the wait-list control, and the internal consistency for the CPQ, once removing the reversely scored items, was Cronbach’s α = .72. Conclusion: The CPQ can be used as a self-report measure in Swedish, but further research on its structural validity is needed.