Development of a Diagnostic Questionnaire for Damp Phlegm Pattern and Blood Stasis Pattern in Coronary Heart Disease Patients (CHD-DPBSPQ)

BACKGROUND: The aim was to develop a diagnostic questionnaire for damp phlegm pattern and blood stasis pattern in coronary heart disease patients (CHD-DPBSPQ). METHODS: The standard procedures of questionnaire development were carried out to develop and assess CHD-DPBSPQ. The patients were assessed using the CHD-DPBSPQ, CHD-DPPQ, and CHD-BSPQ. Four methods were used to select the items on the CHD-DPBSPQ in a pilot study based on data from a Guizhou tertiary grade A hospital. Cronbach's alpha and the split-half reliability, test-retest reliability, content validity, criterion validity, construct validity, and convergent validity were determined in a validation study using a nationwide sample. RESULTS: After item selection, the CHD-DPBSPQ contained 15 items in two domains: the phlegm domain (9 items) and the blood stasis domain (6 items). For the CHD-DPBSPQ, the alpha coefficient was 0.88, the split-half coefficient was 0.90, and the intraclass correlation coefficient was 0.83. The range of the item-level content validity index (I-CVI) was 0.71 to 1.0 and that of the scale-level content validity index/average (Scale-CVI/Ave) was 0.97. The domain scores on the CHD-DPBSPQ were in close relation to the scores on a questionnaire for damp phlegm pattern in coronary heart disease patients (CHD-DPPQ) and a questionnaire for blood stasis pattern in coronary heart disease patient (CHD-BSPQ) (P < 0.01). The root mean square error of approximation (RMSEA) was equal to 0.05 (90% CI: 0.044, 0.059). Convergent validity was demonstrated with a moderate correlation. CONCLUSION: The CHD-DPBSPQ is a reliable and valid instrument.