Our study demonstrates that among patients with diabetes and access to diabetes subspecialty clinic, there was no significant association between functional health literacy and rates of SMBG. Inadequate health literacy was not significantly associated with a lower likelihood of SMBG. This is similar to other studies that reported no association between health literacy and diabetes self-management behaviors (including SMBG).13
However, our patients with inadequate health literacy had lower rates of keeping a record of blood glucose testing results. This may be explained by the complex nature of SMBG, often challenging in patients with inadequate health literacy, who were less likely to correctly interpret or act on self-monitoring results.17
The reported rate of SMBG was very high in the study population compared to the reported rates in the general population. This disparity noted between the rates of SMBG is likely attributed to the fact that the majority of the study population reported receiving diabetes education. The high rates of our study are consistent with those of other studies in which having had patient education class in diabetes management and making frequent physician visits for diabetes care were positively related to self-testing.5
Similar to other studies, financial barriers associated with income, employment status, and health insurance do not appear to impede SMBG. Although the duration of having diabetes was associates with SMBG, this finding should be interpreted with caution because the confidence interval was wide and duration was self-reported.
The following limitations of this study should be acknowledged. First, selection bias is a potential confounding factor because our respondents were selected from 1 specialty hospital-based practice, and the observed results may not be generalizable elsewhere. Second, bias due to self-reporting may have influenced the results. Third, although we hypothesized that health literacy predicted SMBG, our lack of confirmation could be due to the relatively small sample size of our study and the concurrent attendance of many subjects to a subspecialty diabetic clinic where they were already receiving intensive diabetes education. Finally, the cross-sectional design of this survey only captures the reported rates of SMBG of patients receiving intensive education at 1 point in time and may not reflect the actual rates in the population over time periods.
In summary, our findings suggest that inadequate health literacy may have, at best, only a marginal impact on the frequency of SMBG. However, these patients had a high rate of record keeping of blood glucose monitoring results but may have a low rate of understanding how to use the results to manage their disease. Although inadequate health literacy has been associated with worse outcomes in persons with diabetes, these findings may suggest that not understanding the results of SMBG steps may contribute to the mechanisms by which inadequate health literacy is associated with worse diabetes outcomes. Further research is needed to elucidate the mechanisms by which inadequate use of SMBG results worsens diabetes outcomes.