Is diabetes knowledge associated with health-related quality of life among subjects with diabetes?: a preliminary cross-sectional convenience-sampling survey study among English-speaking diabetic subjects in Singapore

Objective: Health-related quality of life (HRQoL) has been increasingly used as an important outcome measure to assess efficacy of diabetes interventions. It was reported that diabetes knowledge contributes to better metabolic control, which is associated with better HRQoL. However, the relationship between diabetes knowledge and HRQoL hasn’t been explored. The objective of the study was to evaluate if diabetes knowledge is associated with HRQoL among English-speaking subjects with diabetes in Singapore. To establish this relationship will not only fill in the knowledge gap, but more importantly would allow improving diabetic patients’ HRQoL by enhancing their disease-related knowledge. Methods: English-speaking subjects (aged >21) with self-reported diabetes were recruited by convenience sampling at a public event organized by Diabetic Society of Singapore to commemorate the World Diabetes Day. Correlation between diabetes knowledge (measured using the General Diabetes Knowledge Test (GDKT), score range 0-100) and HRQoL (measured using the Audit of Diabetes-dependent Quality of life (ADDQoL), score range 0~100;EQ-5D, score range-0.594 to 1) were studied using Pearson correlation coefficients. The relationship between diabetes knowledge and HRQoL was studied using 3 separate multiple linear regression (MLR) models with HRQoL scores as dependent variable and GDKT score as independent variable. No adjustment was made in the first MLR model,while socioeconomic variable(s) and socioeconomic and medical status variables were adjusted respectively in the other 2 models. Results: Data from 42 subjects with complete responses were analyzed (mean (SD) age:53.0(9.61) years, 45% female, 90% with >6 years of education, 64.3% with other chronic medical conditions, 40.5% with diabetes complications). Mean (SD) GDKT, ADDQoL and EQ-5D scores were 33.1(3.53), 46.9(18.56) and 0.9(0.15) respectively. Correlations between diabetes knowledge and ADDQoL and EQ-5D scores were 0.26 and 0.30 respectively. A comparatively modest predictive power of diabetes knowledge was found to explain the variances in ADDQoL and EQ-5D of around 12% (Model II). Conclusion: Our results showed diabetes knowledge to be modestly correlated with both diabetes-specific and generic HRQoL, indicating that diabetes knowledge may be useful as a predictor of HRQoL when modeled properly. Yet, further studies utilizing larger sample size would be required to confirm the observation