Table 2.

Multivariable Cox Proportional Hazard Models of Adherence Trajectories of Oral Hypoglycemics and Risk of Hospitalizations/Emergency Department (ED) Visits

Trajectory group	No. in each group	Diabetes-related hospitalizations/ED visits			All-cause hospitalizations/ED visits
		% in the trajectory group	HR (95 % CI)	P value	% in the trajectory group	HR (95 % CI)	P value
Perfect adherers	1461	14.4	Referent	–	46.3	Referent	–
Nearly perfect adherers	5097	14.4	1.06 (0.90, 1.25)	0.48	51.1	1.17 (1.07, 1.28)	<0.0001
Moderate adherers	3412	18.9	1.48 (1.25, 1.75)	<0.0001	59.5	1.47 (1.34, 1.62)	<0.0001
Low adherers	1796	19.5	1.51 (1.25, 1.83)	<0.0001	64.1	1.59 (1.44, 1.77)	<0.0001
Late discontinuers	1110	15.7	1.21 (0.98, 1.15)	0.08	57.5	1.34 (1.19, 1.51)	<0.0001
Early discontinuers	1570	13.6	1.10 (0.89, 1.36)	0.36	55.4	1.31 (1.17, 1.46)	<0.0001
Non-adherers with 1 fill	1810	14.0	1.35 (1.09, 1.67)	0.006	59.9	1.60 (1.43, 1.79)	<0.0001
C-index (95 % CI)			0.714 (0.682, 0.745)			0.781 (0.729, 0.828)
PDC ≥80 %	5912	13.9	Referent	–	49.4	Referent	–
PDC <80 %	10,344	17.0	1.38 (1.25, 1.51)	<0.0001	59.3	1.29 (1.23, 1.36)	<0.0001
C-index (95 % CI)			0.652 (0.614, 0.694)			0.769 (0.751, 0.786)

Separate multivariable Cox proportional hazard models were used to adjust for sociodemographic factors, health status, and diabetes treatment- and care-related covariates. Final models included age, gender, race/ethnicity, type of health plan, type of Medicaid eligibility, number of outpatient visits, number of emergency department visits, number of hospitalizations, number of prescribers, number of unique pharmacies, average number of monthly prescriptions, Elixhauser comorbidity index, and diabetes complication severity index during the 6 months prior or as of the index date. We also included the number of anti-diabetes medication classes, insulin use, and having diabetes-related tests in the 12 months after the index oral hypoglycemic prescription

ED emergency department, HR hazard ratio, PDC proportion of days covered