Data quality and factor analysis of the Danish version of the Relationship Scale Questionnaire

Background: The Relationship Scale Questionnaire (RSQ) is a widely-used measure of adult attachment, but whether the results obtained by the RSQ fit the attachment construct has only been examined to a limited extent. Objective: The objectives of this study were to investigate the psychometric properties of the Danish translation of the RSQ and to test whether the results are consistent with the hypothesized model of attachment. Methods: The study included two samples: 602 general practitioners and 611 cancer patients. The two samples were analyzed separately. Data quality was assessed by mean, median and missing values for each item, floor and ceiling effects, average inter-item correlations and Cronbach’s α for each subscale. Test-retest was assessed by intra-class correlations among 76 general practitioners. A confirmatory factor analysis was conducted to establish evidence of the four proposed subscales. Due to an inadequate fit of the model, data was randomly split into two equally sized subsamples and an exploratory factor analysis was conducted for all 30 items in the first subsample comprised of 286 cancer patients and 285 general practitioners. The EFA yielded a three-factor structure which was validated through a confirmatory factor analyses in a second subsample comprised of 278 cancer patients and 289 general practitioners. Results: The data quality of the RSQ was generally good, except low internal consistency and low to moderate test-retest reliability. The four subscales of the RSQ were not confirmed by the confirmatory factor analysis. An exploratory factor analysis suggested a three-factor solution for both general practitioners and patients, which accounted for 61.1% of the variance among general practitioners and 62.5% among patients. The new three-factor solution was verified in a confirmatory factor analyses. Conclusion: The proposed four-factor model of the RSQ could not be confirmed in this study. Similar challenges have been found by other studies validating the RSQ. An alternative three-factor structure was found for the RSQ.