A major contributing factor to poor compliance to maintain HbA1c <7% has been found to be a lack of patient awareness (1). Wang et al. (1) showed only 17% of participants understood HbA1c, and 49% of participants had heard of the HbA1c test. Their study also concluded that there was greater awareness of HbA1c among the younger age groups and those with higher education levels. Despite the high prevalence of patients with diabetes in Asia, data on the association between awareness of HbA1c and diabetic retinopathy are not available in the Singapore population.
Our study was a hospital-based, cross-sectional study of 506 diabetic patients aged 23–88 years in Singapore with different racial groups, including Chinese, Malay, Indian, and others.
Of the 623 patients invited, 507 were recruited (81.2% response rate). One was excluded because of incomplete data. The majority of patients who declined to participate cited a lack of time or interest in the study.
There were 257 (50.8%) men and 249 (49.2%) women with median age of 62.1 years. Patients’ education level ranged from no formal education to a postgraduate degree. Two hundred seventy-one (53.6%) patients had diabetic retinopathy, and 148 (29.2%) patients had previous laser treatment.
We found significant differences among patients with different occupations (P < 0.001). There was significantly greater awareness among patients with younger age (P < 0.001), earlier onset of diabetes (P < 0.001), higher education (P < 0.001), those cared by endocrinologists (P < 0.001), and those aware that increased HbA1c (P = 0.007) could cause blindness. More frequent visits to ophthalmologists (P = 0.049) or endocrinologists (P = 0.035) also increased the awareness of HbA1c. However, those cared for by family physicians showed a negative association (P < 0.001). We hypothesize that this was because patients who see family physicians are less likely to have diabetic retinopathy, and thus were less aware of HbA1c and diabetic retinopathy.
There were no significant differences between awareness of HbA1c and sex or race. Having diabetic retinopathy or knowing diabetes could cause blindness was not associated with greater awareness of HbA1c.
With multivariate logistic regression analysis, after adjusting for all other factors, higher education level, younger age, and longer duration of diabetes were still significantly associated with greater HbA1c awareness. The odds of HbA1c awareness decreased by 4% with every increase in age by 1 year (P < 0.001), and increased by 5% with every increase in the duration of diabetes by 1 year (P < 0.001). However, higher education level and being cared for by endocrinologists translates into more awareness (P < 0.001).
Studies by Colleran et al. (2) and Panja et al. (3) demonstrated that a better grading on the Michigan Diabetes Knowledge Test is associated with lower HbA1c values. With each increase in the number of questions answered correctly, HbA1c decreased by 0.239 (r = −0.337, P < 0.003). A meta-analysis by Norris et al. (4) showed that intervention via patient education reduced HbA1c more than the control group by 0.76% (95% CI 0.34–1.18), 0.26% (0.21% increase–0.73% decrease), and 0.26% (0.05–0.48) at immediate, 1–3 months, and ≥4 months follow-up.
In summary, more resources should be channeled toward increasing the awareness levels to reduce the complication of diabetic retinopathy.
Acknowledgments
No potential conflicts of interest relevant to this article were reported.
S.S. designed, conceived, and executed the study and edited the manuscript. Y.C.C. wrote the manuscript. Y.S. analyzed statistics and wrote the results section. E.L.O. collected data. K.G.A.E. edited the manuscript. S.S. is the guarantor of this work and, as such, had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
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