Self-administration and standardisation of the chronic respiratory questionnaire: a randomised trial in three German-speaking countries

AbstractThe chronic respiratory questionnaire (CRQ) has demonstrated excellent measurement properties in patients with chronic obstructive pulmonary disease (COPD), but in its original form it is limited by the requirement for interviewer-administration and the individualised dyspnoea questions. The objective of this randomised trial was to examine the evaluative properties of the interviewer and self-administered German CRQ as well as of a standardised CRQ dyspnoea domain. In a multinational trial we randomly allocated 71 patients with COPD to complete the interviewer administered CRQ (CRQ-IA) or the self-administered CRQ (CRQ-SA) and other validation measures at the beginning and end of a respiratory rehabilitation program. We assessed and compared responsiveness and longitudinal validity of the CRQ. The change scores of all CRQ domains were above the minimal clinically important difference of 0.5. Responsiveness of the fatigue domain was higher for the CRQ-SA compared to CRQ-IA (P=0.02), but there was no difference in responsiveness on the other domains. Compared to the standardised dyspnoea domain the individualised dyspnoea questions tended to show greater responsiveness for both the CRQ-IA (P=0.07) and CRQ-SA (P=0.10). We found better longitudinal validity for the CRQ-SA represented by larger correlations between CRQ change scores and those of other validation instruments. Taken these results into consideration, researchers in COPD, in particular those in German-language countries can utilise any one of four CRQ formats that have proved both valid and responsive

Self-administration and interviewer-administration of the German Chronic Respiratory Questionnaire: instrument development and assessment of validity and reliability in two randomised studies

Abstract Background Assessment of health-related quality of life (HRQL) is important in patients with chronic obstructive pulmonary disease (COPD). Despite the high prevalence of COPD in Germany, Switzerland and Austria there is no validated disease-specific instrument available. The objective of this study was to translate the Chronic Respiratory Questionnaire (CRQ), one of the most widely used respiratory HRQL questionnaires, into German, develop an interviewer- and self-administered version including both standardised and individualised dyspnoea questions, and validate these versions in two randomised studies. Methods We recruited three groups of patients with COPD in Switzerland, Germany and Austria. The 44 patients of the first group completed the CRQ during pilot testing to adapt the CRQ to German-speaking patients. We then recruited 80 patients participating in pulmonary rehabilitation programs to assess internal consistency reliability and cross-sectional validity of the CRQ. The third group consisted of 38 patients with stable COPD without an intervention to assess test-retest reliability. To compare the interviewer- and self-administered versions, we randomised patients in groups 2 and 3 to the interviewer- or self-administered CRQ. Patients completed both the standardised and individualised dyspnoea questions. Results For both administration formats and all domains, we found good internal consistency reliability (Crohnbach's alpha between 0.73 and 0.89). Cross-sectional validity tended to be better for the standardised compared to the individualised dyspnoea questions and cross-sectional validity was slightly better for the self-administered format. Test-retest reliability was good for both the interviewer-administered CRQ (intraclass correlation coefficients for different domains between 0.81 and 0.95) and the self-administered format (intraclass correlation coefficients between 0.78 and 0.86). Lower within-person variability was responsible for the higher test-retest reliability of the interviewer-administered format while between person variability was similar for both formats. Conclusions Investigators in German-speaking countries can choose between valid and reliable self-and interviewer-administered CRQ formats.</p