Aging
Agreement Between Fingerstick Blood Glucose and Continuous Glucose Monitor Measurements Among Long-Term Care Facility Residents Marzan A. Khan* Marzan Khan Medha N. Munshi Christine Slyne Nina R. Joyce Andrew R. Zullo
Background: Long-term care facility (LTCF) residents with comorbid diabetes and Alzheimer’s Disease and Related Dementia (ADRD) are at high risk of hypoglycemia. Continuous glucose monitoring (CGM) is the gold-standard for detecting hypoglycemia including asymptomatic hypoglycemia and involves measuring interstitial glucose at 5-minute intervals over 10-14 days. Observational studies using electronic health record (EHR) data containing fingerstick blood glucose (FBG) measures could help to identify ways to reduce hypoglycemia risk, but we first need to understand the validity of such data.
Objective: To validate EHR-based FBG measures against gold-standard CGM measures of hypoglycemia.
Methods: We studied 2 cohorts in parallel. In the first, we analyzed linked CGM data and Long-Term Care Data Cooperative EHR-based FBG data on residents with comorbid diabetes and ADRD collected in 2023. In the second, we analyzed linked CGM and EHR-based FBG data obtained directly from LTCFs between 2022 and 2023. In both, we defined hypoglycemia as glucose levels < 70 mg/dl and assessed the sensitivity and specificity of FBG versus CGM measures to detect hypoglycemia. The unit of analysis was each pair of contemporaneous FBG-CGM measures.
Results: In the first cohort, 2 White, female residents with a mean (standard deviation [SD]) age of 81[12.7] years generated 25 daily hypoglycemia measurements. The sensitivity and specificity were 14% and 100%, respectively, for FBG-measured hypoglycemia. The second cohort included 40 residents (mean [SD] age 68 [11] years, 45% females, 60% White race) who generated 424 daily measurements of hypoglycemia. The sensitivity and specificity were 13%, and 100%, respectively.
Conclusion: EHR FBG measures of hypoglycemia had high specificity but low sensitivity among LTCF residents. Researchers and healthcare providers should assume hypoglycemia is measured with error in EHRs and account for this in their work.