The reliability and validity of a new self-completed questionnaire (QUIK)

Abstract

In order to evaluate the reliability and validity of a self-completed questionnaire (QUIK), devised to measured QOL, we examined the QUIK scores of elderly who visited the Kumamoto Health Administrative Center for a medical check-up in March 1994. The QUIK questionnaire, which is a close-ended and disease non-specific questionnaire, covered four domains such as physical functioning, emotional adjustment, interpersonal relationships, and attitudes toward life, interacting reciprocally. The mean and standard deviation on QUIK were much better in terms of total score (5.1 +/- 5.4), for each domain score in comparison with the patient group, and even in comparison with the non-patient group. The distribution of total scores on QUIK were as follows: excellent 15%, good 35%, fair 36%, poor 11%, very poor 2% and grossly impaired 0% according to a six-tiered rating scale. The internal consistency in terms of total score was alpha = 0.86. Very close correlation were seen among score, each domain score and satisfaction, being healthy and present state of feeling. If the cut-off points of total score were set between 9 and 10, the sensitivity were 0.65, specificity was 0.65 for the age index, sensitivity 1.00, validity 0.29 for the satisfaction index, while, sensitivity was 0.85 and validity 0.48, for the feeling index. There was a very close reciprocal correlation among the four domains, except for the relation between physical functioning and interpersonal relationship using multiple regression analysis. Further, significant correlations were obtained between the score in each domain and the score based on subtracting each domain score from the total score.