Association of a blood glucose test strip quantity-limit policy with patient outcomes: a population-based study

Importance — Given their high costs, payers have considered implementing quantity limits for reimbursement of blood glucose test strips. The impact of these limits on patient outcomes is unknown.

Objective — To determine whether the introduction of quantity limits for blood glucose test strips in August 2013 was associated with changes in clinical outcomes.

Design — Cross-sectional time series analysis from April 2008 to March 2015 of Ontario residents aged 19 years and older with diabetes who were eligible for public drug coverage. In a sensitivity analysis, we studied high-volume users of test strips, who were most likely to be affected by the quantity limits.

Exposures — Eligible patients were stratified into four mutually exclusive groups based on diabetes therapy: insulin, hypoglycemia-inducing oral diabetes agents, non-hypoglycemia-inducing oral diabetes agents, and no drug therapy.

Main Outcomes and Measures — The primary outcomes were emergency department visits for hypoglycemia or hyperglycemia, and the secondary outcome was mean hemoglobin A1c (HbA1c) levels. Outcomes were measured for all patients in each quarter, stratified by age group (<65 vs. ≥65 years) and diabetes therapy.

Results — By the end of the study period, 834,309 people met our inclusion criteria. Among those younger than 65 years, the rate of hypoglycemia and hyperglycemia declined over the study period (from 4.9 to 3.0 visits per 1,000 Ontario drug benefit (ODB)-eligible and from 4.2 to 3.6 visits per 1,000 ODB-eligible, respectively) and wasn’t significantly impacted by the introduction of quantity limits (p-value=0.67 and p-value=0.37, respectively). Similarly, among those aged 65 and older, rates of hypoglycemia and hyperglycemia declined over the study period (from 2.9 to 1.3 visits per 1,000 eligible and from 0.8 to 0.5 visits per 1,000 eligible, respectively) and wasn’t significantly impacted by the introduction of quantity limits (p-value=0.12 and p-value=0.24, respectively). Results were consistent for the secondary outcome of mean HbA1c levels and in the sensitivity analysis of high volume test strip users (p>0.05 for all comparisons).

Conclusions and Relevance — The imposition of quantity limits for blood glucose test strips was not associated with worsening short-term outcomes, suggesting that these policies can reduce costs associated with test strips without causing patient harm.