The Evaluation Of The Reliability And Validity Of SAQ Applied In A Group Of Chinese Patients With CHD

Objectives:The study of quality of life need a perfect instrument, most of the questionnaires used in China are translated from western countries, however the validity and the repeatability in Chinese population should be evaluated before it is used. Seattle Angina Questionnaire (SAQ), As an instrument to measure the quality of life for coronary heart disease (CHD) , has been widely used in the western countries, but it has not been evaluated the application in China. The objective of this study is to evaluate the reliability and validity of the SAQ used in Chinese patients with CHD. Methods:A survey was carried out from April 19th to August 24th in two hospitals, all the patients with CHD, diagnosed based on the criteria of WHO, were included except that whose age was under 35 years old. 124 persons were selected but only 118 valid questionnaires of SAQ were obtained. Among them, Male 56, female 62, the range of age 43 -80, average 64.35 + 8.91 years old. Firstly, 35 cases repeated the interview in 14 days for reliability analysis. Secondly, we selected 50 patients randomly to finish the Short form 36 (SE-36) for criterion validity. At last, all the subjects were asked to repeat the measurement after three months for the responsiveness. Results:1. The documents re-translated to English is consistent with the original version and 93.7 per cent of the subjects consider it easy or very easy to answer the questions.2. The test-retest reliability for the five domains and the overall scales were 0.989, 0.576, 0.969, 0.982, 0.980, 0.939,P=0.000*; The Split-half reliability was Rh=0.842,P=0.000*, R=0.914; The Internal consistency for the five domains and the overall scales were 0.937, 1, 0.519, 0.717, 0.428, 0.759, respectively.3. SF-36 was used as the criterion to evaluate the criterion validity, the r=0.613(N=46), a= 0.01(two-sided),P=0.000; the structure validity was evaluated by factor analysis, we get fivefactors, and the accumulated variance devoted rate was 76.560%.4. The t-test was employed to evaluate the responsiveness of this instrument. Firstly, we divided all the subjects into two groups by inpatients or outpatients, t=-5.585,P=0.000*. Secondly, we divided all the subjects into three groups by the changes of the their illness, t-test was employed to evaluate whether if it can reflect the changes, and saw that the questionnaire can differentiate the changes, so we can concluded that the instrument has satisfied reliability and validity.Conclusions:Based on the analyses, the Chinese version SAQ is good in its validity, reliability and responsiveness. It's easy to perform, and it should be a good instrument for the evaluation of life of quality in CHD patients in China.