Table 2.

12-month pre- and Postbaseline Differences in a Cohort of 17,422 Insulin-Treated Patients with Type 2 Diabetes Who Used SMBG, Had HbA1c <8%, and No Recent Severe Hypoglycemia

	Real-time continuous glucose monitor initiators (n = 149)			Noninitiators (n = 17,273)			Difference in differences
Percent (%) unless otherwise indicated	Prebaseline	Postbaseline	Pre–Post differencea	Prebaseline	Postbaseline	Pre–Post differencea	Unweighted and unadjustedb (95% CI)	Weighted and adjustedc (95% CI)	P
HbA1c (mean)	6.98	6.92	−0.06	7.10	7.42	0.32	−0.37 (−0.50, −0.24)	−0.30 (−0.50, −0.10)	0.004
HbA1c <7%	40.3	53.7	13.4	35.1	33.2	−1.9	15.2 (6.2, 24.2)	11.7 (−1.2, 24.6)	0.08
HbA1c <8%	100	87.8	−12.2	100	76.6	−23.4	11.2 (5.8, 16.5)	5.3 (−1.6, 12.3)	0.13
HbA1c >9%	0	1.4	1.4	0	6.6	6.6	−5.2 (−7.1, −3.3)	−4.0 (−7.0, −1.0)	0.009
Hypoglycemia event (ED or hospitalization)	0	3.4	3.4	0	2.06	2.06	1.30 (−1.61, 4.19)	1.70 (−1.69, 5.10)	0.33

^a Pre–post difference is calculated as postbaseline value minus prebaseline value.

^b DiD (95% CI) is calculated as ([postbaseline value minus prebaseline value in CGM initiators] minus [postbaseline value minus prebaseline value in CGM noninitiators]) from repeated-measures generalized linear models; there are slight discrepancies between the unadjusted/unweighted model-based DiD and the crude DiD for the HbA_1c outcomes due to missing data. Patients with ≥1 HbA_1c measure in either the pre- or postbaseline were included in the model.

^c Overlap weighting was based on propensity score model and adjusted for variables identified in the directed acyclic graph as critical adjusters (prebaseline insulin treatment, glycemic control, and acute metabolic crisis) and baseline covariates with |D| > 0.10 after weighting. Conservative 95% confidence intervals for both DiD estimates were estimated using robust variance estimators.⁷

DiD, difference-in-differences.