Rates of severe hypoglycemia increased with higher ADI regardless of the patient’s diabetes treatment regimen (bolus insulin–treated patients living in Q5 vs Q1 counties: IRR, 1.30 [95% CI, 1.18-1.43; P < .001]; basal insulin–treated patients living in Q5 vs Q1 counties: IRR, 1.33 [95% CI, 1.18-1.50; P < .001]; and noninsulin-treated patients living in Q5 vs Q1 counties: IRR, 1.48 [95% CI, 1.32-1.65; P < .001]). Here, INS is linked to diabetes mellitus.