IMPACT OF COMPLICATIONS ON THE QUALITY OF LIFE OF PEOPLE WITH DIABETES: A STUDY BASED ON EQ-5D

Purpose: The aim of this study was to describe how diabetes complications influence the quality of life of persons with diabetes.

Method: We mailed a questionnaire to 1,000 persons with diabetes type 1 and 2 in Norway and received 598 valid responses after two reminders. The questionnaire had questions about socio-demographic characteristics, use of health care, diabetes complications and finally the EQ-5D questionnaire. Ordinal logistic regression was considered to explore determinants of responses to the EQ-5D dimensions. However, the Brandt test revealed violation of the proportional odds assumption. Consequently, we merged level 2 and 3 on the EQ-5D dimensions and performed binary logistic regressions. The EQ-5D index was initially analysed with linear OLS regression and Tobit models. The Breusch-Pagan test and plotting residuals versus fitted values indicated that heteroscedasticity was present both for type 1 and type 2 diabetes. Therefore OLS with White’s robust variance estimators was used to explore determinants of the EQ-5D index.

Result: In multivariate analyses the strongest determinants of reduced mobility were neuropathy (OR: type 1 diabetes 10.67, OR: type 2 diabetes 11.44), and ischemic heart disease (OR type 1 diabetes: 22.35, OR type 2 diabetes 2.06). “Fear of hypoglycaemia” was a strong predictor (OR type 1 diabetes: 4.12, OR type 2 diabetes 5.71) of anxiety and depression. For patients without complications, the EQ-5D index was 0.90 (type 1 diabetes) and 0.85 (type 2 diabetes). For patients with complications, the EQ-5D index was 0.68 (type 1 diabetes) and 0.73 (type 2 diabetes). In linear regression the factors with the greatest negative impact on the EQ-5D index were ischemic heart disease (coefficient -0.181 for type 1 diabetes), stroke (– 0.291 for type 1 diabetes and – 0.135 for type 2 diabetes), neuropathy (-0.358 for type 1 diabetes and -0.187 for type 2 diabetes) and fear of hypoglycaemia (-0.078 for type 2).

Conclusion: Diabetes complications may have a considerable impact on several dimensions of quality of life, and the impact may be substantial. The strongest determinants of reduced quality of life in diabetics were ischemic heart disease, stroke and neuropathy. The complexity of the disease means that several dimensions need to be considered when priorities are set for diabetes interventions.