Trends of insulin use among US adults with type 2 diabetes: the Behavioral Risk Factor Surveillance System, 1995-2007.

Objective: People with type 2 diabetes may need insulin therapy to compensate for their underlying pathogenic abnormalities and to improve glycemic control. We examined trends of insulin use among US adults aged ≥40 years with type 2 diabetes.

Methods: We analyzed data from the Behavioral Risk Factor Surveillance System collected annually during 1995-2007. Insulin use was assessed by self-report. Log-linear regression analyses with a robust error variance estimator were performed to estimate the prevalence, prevalence ratios, and their 95% confidence intervals.

Results: The overall crude and age-standardized proportion of insulin use decreased from 35% and 36% in 1995 to 23% and 22% in 2007, respectively. After adjustments for age, sex, race/ethnicity, education attainment, body mass index, and diabetes duration, the overall prevalence decreased from 33% to 22% (P<.0001 for linear trend). The decreasing rates were similar across sex (P=.23 for interaction between sex and survey year) and race/ethnicity (P=.35 for interaction between race/ethnicity and survey year).

Conclusion: The proportion of insulin use decreased from 1995 to 2007 among US adults aged ≥40 years. Continuing efforts may be needed to properly identify those who may need to initiate and maintain insulin therapy among patients with type 2 diabetes as medically indicated.