Cost-Related Suboptimal Insulin Use

Insulin is a necessary, life-changing medication for patients living with Type 1 or Type 2 Diabetes Mellitus. Yet, a recent study at an endocrinology clinic in New England indicated that one quarter of patients experienced cost-related suboptimal insulin use. A new study based out of a primary care clinic in the Appalachian region looked at the prevalence of cost-related suboptimal insulin use within this region. The hypothesis is cost-related insulin suboptimal use is higher in the Appalachian region than as reported in the New England area. Surveys were administered to patients who were 18 years of age or older, diagnosed with Type 1 or Type 2 Diabetes Mellitus, and who had been prescribed insulin in the last 12 months. The survey instrument used was adopted and modified from the previous New England study. The survey instrument included 28 items and was administered in person prior to the start of the COVID-19 pandemic from July 2019 to April 2020. Following the start of the COVID-19 pandemic, in person recruitment was suspended. Beginning November 2020, a revised telephonic recruitment began and continued through December 2021. Interested participants were mailed the survey and consent form along with a postage paid return envelope. After the COVID-19 outbreak, the original survey instrument was revised to include 12 additional items designed to measure the impact of COVID-19 on the participant’s diabetes management and on insulin utilization. The primary outcome was cost-related underuse of insulin within the past year. This was measured by a positive response in the questionnaire to at least 1 of 6 questions: did you… (1) use less insulin than prescribed, (2) try to stretch out your insulin, (3) take smaller doses of insulin than prescribed, (4) stop using insulin, (5) not fill an insulin prescription, or (6) not start insulin… because of cost? Descriptive analysis was conducted using SPSS software. The East Tennessee State University Institutional Review Board approved the study protocol. Ninety respondents completed the survey. The average age of respondents was 68 years. The majority were diagnosed with type 2 diabetes (83%), Caucasian race (99%), male (59%), retired or disabled (76%), and had Medicare Part D prescription benefits (63%). The average monthly out-of-pocket cost for insulin was $84.10 (range $0-$566). For the primary outcome, results indicate 44.4% of participants in the Appalachian Mountain community experience cost-related suboptimal therapy. Forty participants completed the revised survey measuring the impact of COVID-19 on their diabetes self-management. From this group, 85% of participants reported their income and job did not change during the pandemic. However, increased dosing of insulin (30%) and increased insulin cost (27.5%) was reported. Respondents also reported increased stress (57.5%), worsened diet (25%) and worsened exercise (40%) as a result of the pandemic. Overall, a higher proportion of people with diabetes in the Appalachian region reported cost-related suboptimal insulin use compared to a previous study. The COVID-19 pandemic also has reportedly contributed to increased insulin requirements in one-third of the surveyed participants