title: Patient experiences questionnaire for interdisciplinary treatment for substance dependence (PEQ-ITSD): reliability and validity following a national survey in Norway.
abstract: Patient experiences are an important aspect of health care quality, but there is a lack of validated instruments for their measurement in the substance dependence literature. A new questionnaire to measure inpatients' experiences of interdisciplinary treatment for substance dependence has been developed in Norway. The aim of this study was to psychometrically test the new questionnaire, using data from a national survey in 2013.
  
  
  
  The questionnaire was developed based on a literature review, qualitative interviews with patients, expert group discussions and pretesting. Data were collected in a national survey covering all residential facilities with inpatients in treatment for substance dependence in 2013. Data quality and psychometric properties were assessed, including ceiling effects, item missing, exploratory factor analysis, and tests of internal consistency reliability, test-retest reliability and construct validity.
  
  
  
  The sample included 978 inpatients present at 98 residential institutions. After correcting for excluded patients (n = 175), the response rate was 91.4%. 28 out of 33 items had less than 20.5% of missing data or replies in the "not applicable" category. All but one item met the ceiling effect criterion of less than 50.0% of the responses in the most favorable category. Exploratory factor analysis resulted in three scales: "treatment and personnel", "milieu" and "outcome". All scales showed satisfactory internal consistency reliability (Cronbach's alpha ranged from 0.75-0.91) and test-retest reliability (ICC ranged from 0.82-0.85). 17 of 18 significant associations between single variables and the scales supported construct validity of the PEQ-ITSD.
  
  
  
  The content validity of the PEQ-ITSD was secured by a literature review, consultations with an expert group and qualitative interviews with patients. The PEQ-ITSD was used in a national survey in Norway in 2013 and psychometric testing showed that the instrument had satisfactory internal consistency reliability and construct validity.
authors.affiliation: Norwegian Institute of Public Health, PO Box 4404, Nydalen, N-0403, Oslo, Norway. mona.haugum@fhi.no.
authors.forename: Mona
authors.identifier: 0000-0002-4615-9047
authors.initials: M
authors.lastname: Haugum
authors.affiliation: Norwegian Institute of Public Health, PO Box 4404, Nydalen, N-0403, Oslo, Norway.
authors.forename: Hilde Hestad
authors.initials: HH
authors.lastname: Iversen
authors.affiliation: Norwegian Institute of Public Health, PO Box 4404, Nydalen, N-0403, Oslo, Norway.
authors.forename: Oyvind
authors.initials: O
authors.lastname: Bjertnaes
authors.affiliation: Norwegian Institute of Public Health, PO Box 4404, Nydalen, N-0403, Oslo, Norway.|Department of Health Management and Health Economics, University of Oslo, Faculty of Medicine, Institute of Health and Society, PO Box 1130, Blindern, 0318, Oslo, Norway.
authors.forename: Anne Karin
authors.initials: AK
authors.lastname: Lindahl
mesh_terms: D000328:Adult; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007297:Inpatients / Q000523:psychology; D008297:Male; D009664:Norway; D017060:Patient Satisfaction; D011594:Psychometrics; D015203:Reproducibility of Results; D019966:Substance-Related Disorders / Q000523:psychology*; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Interdisciplinary treatment substance dependence; Patient satisfaction; Questionnaire; Reliability; Substance use disorders; Survey; Validity