Severe hypoglycemia rates and associated costs among type 2 diabetics starting basal insulin therapy in the United States.

OBJECTIVES

To derive current real-world data on the rates and costs of severe hypoglycemia (SH) for people with type 2 diabetes mellitus (T2D) who have initiated basal insulin therapy and to examine differences in SH rates and costs stratified by history of prior SH events.

METHODS

We used a nation-wide electronic health records database that included encounter and laboratory data, as well as clinical notes, to estimate the rates and costs of SH events among adults with T2D who initiated basal insulin between 2008 and 2011. Unadjusted and regression-adjusted rates and quarterly costs were calculated for all patients as well as stratified by history of a SH event before starting basal insulin and history of a SH event during the basal insulin titration period.

RESULTS

We identified 7235 incident cases of basal insulin use among patients with T2D who did not use insulin during the previous 12 months. Regression-adjusted incidence and total event rates were 10.36 and 11.21 per 100 patient-years, respectively. A history of SH events during the pre-index baseline and post-index titration periods were statistically significantly associated with both the incidence and total event rates (p < 0.01). Regression-adjusted total healthcare and diabetes-related costs were statistically significantly (p < 0.01) higher in those quarters when a SH event occurred than in those quarters without any SH events ($3591 vs. $487 and $3311 vs. $406, respectively). A history of previous SH or SH events during the titration period were not statistically significantly associated with costs.

CONCLUSIONS

These results suggest that the real-world burden of SH is high among people with T2D who start using basal insulin and that history of previous SH events, both before starting insulin and during the insulin titration period, influences future SH. These results can also provide insights into interventions that can prevent or delay SH. These results should, however, be interpreted in light of the key limitations of our study: not all SH events may have been captured or coded in the database, data on filled prescriptions were not available, and the post-titration follow-up period could have been divided into time units other than quarters (3 month blocks) resulting in potentially different conclusions. Further real-world studies on the frequency and costs of SH, using methods to identify as many SH events as possible, can allow healthcare providers to make more informed decisions on the risks and benefits of basal insulin therapy in T2D patients.