Table 2.

Parameter Estimate for Insulin Initiation Categories from Inverse Probability Treatment Weight (IPTW)-Adjusted Ordinary Least Squares Regression of Change in Glycosylated Hemoglobin (HbA1c) Values from Baseline to 1-Year Follow-Up in Older Medicare Beneficiaries with Type 2 Diabetes Mellitus: Humana Medicare Advantage Prescription Drug Database (N = 4,028)

Insulin Initiation Category	All, N = 4,028			Baseline HbA1c
	n	β (SE)	P-Value	<7.0%, n = 543			7.0–7.9%, n = 1,047			8.0–8.9%, n = 1,013			≥9.0%, n = 1,425
				n	β (SE)	P-Value	n	β (SE)	P-Value	N	β (SE)	P-Value	n	β (SE)	P-Value
1 OAD	1,075	−0.40 (0.07)	≤.001	188	−0.20 (0.11)	.06	258	−0.12 (0.08)	.15	244	−0.28 (0.10)	.003	385	−0.70 (0.13)	≤.001
2 OADs	2,020	−0.18 (0.07)	.008	256	−0.04 (0.10)	.71	515	−0.03 (0.08)	.67	516	−0.25 (0.09)	.007	733	−0.24 (0.13)	.06
≥3 OADs	933	Reference		99	Reference		274	Reference		253	Reference		307	Reference

SE = standard error.

Regression model was adjusted for IPTWs and controlled for clinical (complexities specific to older adults, adapted Diabetes Complications Severity Index, co-occurring conditions, baseline hypoglycemia events), demographic (sex, race, region), and insurance (Medicare prescription drug, coverage gap status, type of insurance plan) characteristics; healthcare use in baseline period (any inpatient visit, any emergency department visit, number of diabetes-related office visits); and year of observation.

Significant group differences according to insulin initiation category (1 and 2 oral antidiabetes drugs (OADs)) compared with delayed insulin initiation (≥3 OADs), based on OLS regression.