The German version of the Pulmonary Embolism Quality of Life (PEmb-QoL) questionnaire: reliability, responsiveness and structural validity

Purpose The Pulmonary Embolism Quality of Life (PEmb-QoL) questionnaire is the only existing disease-specific instrument for measuring quality of life after pulmonary embolism (PE). It includes six dimensions: frequency of complaints, limitations in activities of daily living, work-related problems, social limitations, intensity of complaints and emotional complaints. The present study aimed to determine the psychometric properties including responsiveness and structural validity of the German version. Methods The analysis used data from participants of the LEA cohort study at University Hospital Augsburg. The PEmb-QoL was administered via postal surveys 3, 6 and 12 months post-PE. Internal consistency and test-retest reliability were evaluated by calculating Cronbach's alpha and intra-class correlation coefficients (ICC). Standardized response means (SRM) were calculated for investigating responsiveness. For evaluating the fit of the factor structure, confirmatory factor analysis (CFA) was conducted. Results Overall, we used data from 299 patients 3 months after PE. Cronbach's alpha (0.87-0.97) and ICC (0.53-0.90) were in an acceptable to good range. SRM scores showed good responsiveness of all dimensions. CFA revealed the four-factor model including one general factor to have a good model fit. Conclusion Despite existing floor effect, most standard criteria of reliability and validity were met and indications for appropriateness of the PEmb-QoL summary score could be found. Apart from some restrictions concerning the factor structure and the dimension of social limitations, our results support the use of the PEmb-QoL questionnaire for evaluating PE-specific quality of life. Future studies should seek replication in different samples to ensure generalizability of the findings.