Study on the Reliability and Validity of the Japanese-language Version of the Mishel Uncertainty in Illness Scale-Community Form

Abstract

The purpose of this study is to examine the reliability and validity of the Japanese-language version of the Mishel Uncertainty in Illness Scale-Community Form (MUIS-C). The scale has been developed to measure perceived uncertainty among chronically ill patients or their families. As such, outpatients suffering from autoimmune diseases and type-2 diabetes participated in the study. In terms of internal reliability, the results were sufficient (i. e., above the criteria value). Cronbach's coefficient alpha was 0.82 and 0.88. When the Spearman-Brown split half formula was incorporated into the split-half method, the coefficients were 0.71 and 0.86. However, the test-retest method obtained r=0.61 for type-2 diabetes patients, which is slightly smaller than the criteria value of 0.7. In terms of validity, since the responses closely agreed with the characteristics of their illnesses, clinical validity is sufficient. Concurrent validity was supported by the correlation coefficient between MUIS-C and the scale of Problem Area in Diabetes Survey and was 0.42 (p<0.01). Construct validity was evaluated based on the model of perceived uncertainty in illness. Multiple linear regression analysis indicated that uncertainty, symptom instability, and social support were significantly related to the quality of life which corresponds to a psychological adaptation of the model of perceived uncertainty in illness. Therefore, this study suggests that the Japanese-language version of MUIS-C is in need of further refinement, but is considered an efficient tool for clinical use.