Table 3.
Unadjusted and adjusted characteristics for insulin adherent and nonadherent cohorts during 12-month follow-up period
| Patient characteristics | Adherent N=7,486 |
Nonadherent N=16,706 |
Unadjusted analysis
|
Adjusted analysis
|
||||
|---|---|---|---|---|---|---|---|---|
| OR | 95% CI | P-value | OR | 95% CI | P-value | |||
| Age group, n (%) | ||||||||
| <40 | 224 (3.0) | 789 (4.7) | 1.24 | 1.05–1.47 | 0.009 | 1.13 | 0.93–1.37 | 0.224 |
| [40–49] | 1,263 (16.9) | 2,311 (13.8) | 2.40 | 2.17–2.65 | <0.001 | 2.09 | 1.83–2.40 | <0.001 |
| [50–59] | 3,458 (46.2) | 5,647 (33.8) | 2.68 | 2.47–2.92 | <0.001 | 2.07 | 1.88–2.28 | <0.001 |
| [60–69] | 1,656 (22.1) | 4,079 (24.4) | 1.78 | 1.62–1.95 | <0.001 | 1.41 | 1.28–1.56 | <0.001 |
| ≥70 | 885 (11.8) | 3,880 (23.2) | 1 (reference) | 1 (reference) | ||||
| Female, n (%) | 3,807 (50.9) | 8,169 (48.9) | 1.08 | 1.02–1.14 | 0.005 | 0.95 | 0.89–1.01 | 0.100 |
| Retired, n (%) | 5,087 (68.0) | 11,746 (70.3) | 0.90 | 0.84–0.95 | <0.001 | 1.32 | 1.20–1.45 | <0.001 |
| Index insulin source, n (%) | ||||||||
| Human insulin | 4,102 (54.8) | 8,445 (50.6) | 1 (reference) | 1 (reference) | ||||
| Insulin analog | 3,215 (42.9) | 6,246 (37.4) | 1.06 | 1.00–1.12 | 0.045 | 1.07 | 1.00–1.14 | 0.036 |
| Animal-derived insulin | 169 (2.3) | 2,015 (12.1) | 0.17 | 0.15–0.20 | <0.001 | 0.46 | 0.36–0.59 | <0.001 |
| Index insulin action profile, n (%) | ||||||||
| Prandial insulin | 264 (3.5) | 2,364 (14.2) | 0.22 | 0.19–0.25 | <0.001 | 0.55 | 0.45–0.68 | <0.001 |
| Basal insulin | 870 (11.6) | 1,995 (11.9) | 0.85 | 0.78–0.92 | <0.001 | 0.79 | 0.72–0.87 | <0.001 |
| Premixed insulin | 6,352 (84.9) | 12,347 (73.9) | 1 (reference) | 1 (reference) | ||||
| Count of A1c tests, mean (SD) | 0.38 (0.66) | 0.32 (0.63) | 1.16 | 1.11–1.20 | <0.001 | 1.19 | 1.13–1.25 | <0.001 |
| Any claims-based hypoglycemic events, n (%) | 35 (0.5) | 166 (1.0) | 0.47 | 0.32–0.67 | <0.001 | 0.62 | 0.42–0.91 | 0.015 |
| Comorbidities and complications | ||||||||
| CCI, mean (SD) | 1.64 (1.21) | 2.13 (1.51) | 0.75 | 0.73–0.76 | <0.001 | 0.93 | 0.91–0.96 | <0.001 |
| Hypertension, n (%) | 2,411 (32.2) | 9,628 (57.6) | 0.35 | 0.33–0.37 | <0.001 | 0.47 | 0.44–0.50 | <0.001 |
| Dyslipidemia, n (%) | 1,378 (18.4) | 4,967 (29.7) | 0.53 | 0.50–0.57 | <0.001 | 0.74 | 0.68–0.80 | <0.001 |
| Retinopathy, n (%) | 1,268 (16.9) | 2,789 (16.7) | 1.02 | 0.95–1.09 | 0.639 | 0.98 | 0.91–1.07 | 0.698 |
| Neuropathy, n (%) | 2,146 (28.7) | 3,433 (20.5) | 1.55 | 1.46–1.65 | <0.001 | 1.33 | 1.24–1.43 | <0.001 |
| Nephropathy, n (%) | 1,653 (22.1) | 2,514 (15.0) | 1.60 | 1.49–1.71 | <0.001 | 1.40 | 1.30–1.52 | <0.001 |
| Count of unique OAD drug classes, mean (SD) | 2.45 (1.28) | 2.12 (1.29) | 1.21 | 1.18–1.24 | <0.001 | 1.16 | 1.13–1.19 | <0.001 |
| Any hospitalizations, n (%) | 1,127 (15.1) | 4,350 (26.0) | 0.50 | 0.47–0.54 | <0.001 | 0.94 | 0.86–1.02 | 0.148 |
| Direct medical cost ($), mean (SD) | 753 (1,430) | 887 (1,519) | 0.96 | 0.94–0.97 | <0.001 | 0.97 | 0.95–0.99 | 0.006 |
Note: OR >1 indicates that patients were more likely to be adherent than the reference group.
Abbreviations: SD, standard deviation; OR, odds ratio; CI, confidence interval; CCI, Charlson Comorbidity Index; OAD, oral antidiabetic medication.