Factors associated with adherence to oral antihyperglycemic monotherapy in patients with type 2 diabetes

Figures & data

Figure 1 Study observation period for inception cohort.

Notes: Index date is the first prescription date in the index period. If patients are eligible multiple times for study inclusion during the observation period, only the first qualified medication episode is included.
Abbreviation: T2DM, type 2 diabetes mellitus.

Figure 2 Adherence by concomitant medications and age groups.

Notes: *P<0.0001 versus reference group; ^†reference group for concomitant medications is ≥3 medications; ^‡reference group for age is ≥65 years.
Abbreviation: PDC, proportion of days covered.

Figure 3 Adherence by age group and sex.

Note: *P<0.0001 versus reference group (≥65 years).
Abbreviation: PDC, proportion of days covered.

Table 1 Patient characteristics at baseline

	Overall (N=133,499)
	n	Mean (SD) or %
Mean age (years)	133,499	60.7 (12.6)
Age groups (year)
<45	11,844	8.9%
45–64	75,254	56.4%
≥65	46,401	34.8%
Sex
Female	65,955	49.4%
Male	67,544	50.6%
Concomitant medications
None	12,946	9.7%
1	23,899	17.9%
2	31,597	23.7%
≥3	65,057	48.7%
Oral antihyperglycemic Agents (OAHA)
Metformin	94,529	70.8%
TZD	16,290	12.2%
SU	15,589	11.7%
DPP-4i	4,382	3.3%
Others*	2,709	2.0%
Dosing frequency of OAHA
Once daily	52,633	39.4%
Twice daily	80,866	60.6%
Comorbidities
Myocardial infarction	3,078	2.3%
Cerebrovascular	6,080	4.6%
Congestive heart failure	7,675	5.7%
Chronic pulmonary disease	7,925	5.9%
Dementia	761	0.6%
Leukemia	268	0.2%
Lymphoma	613	0.5%
Metastatic solid tumor	514	0.4%
Mild liver	3,320	2.5%
Peptic ulcer disease	682	0.5%
Peripheral vascular disease	6,570	4.9%
Rheumatologic disease	2,189	1.6%
Renal disease	4,206	3.2%
Moderate/severe liver disease	641	0.5%
Any tumor	10,894	8.2%
Hemiplegia/paraplegia	3,111	2.3%
Average daily out-of-pocket pharmacy expenses for oral antihyperglycemic monotherapy
Mean (SD)	133,499	$0.25 (0.33)
Median (Interquartile range)	133,499	$0.17 (0.11–0.28)

Note:

* Individuals who switch therapies during follow-up without violating the monotherapy requirement.

Abbreviations: SD, standard deviation; TZD, thiazolidinedione; SU, sulfonylurea; DPP-4i, dipeptidyl peptidase-4 inhibitor.

Figure 4 Logistic regression results for factors associated with adherence to oral antihyperglycemic monotherapy (PDC ≥80%)*.

Notes: *Adjusted for baseline characteristics and comorbid conditions; ^†reference categories: female, age ≥65 years, previously on oral antihyperglycemic monotherapy treatment, once-daily dose, and ≥3 concomitant prescriptions; ^‡an OR >1 indicates a positive association with adherence and an OR <1 indicates a negative association with adherence.
Abbreviations: PDC, proportion of days covered; OR, odds ratio; CI, confidence interval; vs, versus.