Diabetes, Metabolic Syndrome and Obesity (Feb 2021)

The Psychometric Properties of General Adherence Scale in Chinese (GAS-C) in Patients with Type 2 Diabetes Using Insulin

  • Shi Z,
  • Chang J,
  • Ma X,
  • Yin F,
  • Ma M,
  • Li W,
  • Zhu B,
  • Ai Z,
  • Zhao X

Journal volume & issue
Vol. Volume 14
pp. 801 – 811

Abstract

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Zhidao Shi,1,* Jingzhi Chang,2,* Xiquan Ma,3 Feiyan Yin,1 Min Ma,4 Wentian Li,4 Binggen Zhu,1 ZiSheng Ai,1,5 Xudong Zhao1 1Shanghai Pudong New Area Mental Health Center, Tongji University School of Medicine, Shanghai, People’s Republic of China; 2Department of Preventive Medicine, School of Public Health, Jiamusi University, Jiamusi, Heilongjiang Province, People’s Republic of China; 3Department of Psychosomatic Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China; 4Clinical Psychology Department, Wuhan Mental Health Center, Tongji Medical College of Huazhong University of Science & Technology, Wuhan, Hubei Province, People’s Republic of China; 5Department of Medical Statistics, Tongji University School of Medicine, Shanghai, People’s Republic of China*These authors contributed equally to this workCorrespondence: Zhidao Shi; Xudong ZhaoShanghai Pudong New Area Mental Health Center, Tongji University School of Medicine, 165 San-Lin Road, Shanghai, 200124, People’s Republic of China; Email [email protected]; [email protected]: Translate General Adherence Scale (GAS) into Chinese and test its psychometric properties in middle-aged and elderly type 2 diabetes (T2D) patients using insulin in the Han people of urban China.Subjects and Methods: We translated the GAS into Chinese and established General Adherence Scale in Chinese (GAS-C). 136 T2D subjects were selected for testing GAS-C’s reliability and validity, of which 100 study subjects were retested with GAS-C two weeks later. The other 200 T2D subjects were selected for performing Confirmatory Factor Analysis(CFA). The ceiling effect and floor effect of GAS-C data were checked.Results: No data was lost in our research. In exploratory factor analysis(EFA), the Kaiser-Meyer-Olkin measure of sampling adequacy (KMO) =0.899, Bartlett’s Test’s χ2=611.821 (df=10 p< 0.001). The communalities of the items were between 0.740 and 0.862; The values of Measure of Sampling Adequacy (MSA) were between 0.883 and 0.945. All five items entered the factor analysis process. A common factor was extracted, and it could explain 81.403% of the total variance. CFA validated the.one-factor model was good fits with the data of GAS-C (Ratio of Chi-square to Degrees of Freedom (CMIN/DF)=2.032, Goodness of Fit Index (GFI) =0.981, Comparative Fit Index (CFI) =0.996, Tucker–Lewis Index (TLI) =0.992, Root Mean Square Residual (RMR) =0.011, Root Mean Square Error of Approximation (RMSEA) =0.072). Correlation analysis was performed between GAS-C and MMAS-8 to calculate the criterion-related validity (r=0.542 p< 0.001). The internal consistency reliability α=0.942, Intraclass Correlation Coefficient (ICC)= 0.941 (95% CI 0.924– 0.955). The correlation coefficient r of the test-retest reliability was 0.772 (p< 0.001). Spearman-Brown coefficient of split-half was 0.939. There was no floor effect and ceiling effect on the data.Conclusion: GAS-C has good reliability and validity. It can be used for general adherence studies of middle-aged and elderly type 2 diabetic patients using insulin in the Han people of Chinese cities.Keywords: general adherence, type 2 diabetes, reliability, validity, revised scale, scale

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