Table 4.
Unadjusted and adjusted characteristics for insulin persistent and nonpersistent cohorts during 12-month follow-up period
| Patient characteristics | Persistent N=12,823 |
Nonpersistent N=11,369 |
Unadjusted analysis
|
Adjusted analysis
|
||||
|---|---|---|---|---|---|---|---|---|
| HR | 95% CI | P-value | HR | 95% CI | P-value | |||
| Age group, n (%) | ||||||||
| <40 | 397 (3.1) | 616 (5.4) | 1.16 | 1.07–1.27 | 0.001 | 1.24 | 1.11–1.39 | <0.001 |
| [40–49] | 1,990 (15.5) | 1,584 (13.9) | 0.71 | 0.67–0.76 | <0.001 | 0.80 | 0.74–0.88 | <0.001 |
| [50–59] | 5,329 (41.6) | 3,776 (33.2) | 0.65 | 0.62–0.68 | <0.001 | 0.77 | 0.73–0.82 | <0.001 |
| [60–69] | 3,047 (23.8) | 2,688 (23.6) | 0.76 | 0.72–0.81 | <0.001 | 0.89 | 0.84–0.94 | <0.001 |
| ≥70 | 2,060 (16.1) | 2,705 (23.8) | 1 (reference) | 1 (reference) | ||||
| Female, n (%) | 6,319 (49.3) | 5,657 (49.8) | 1.01 | 0.98–1.05 | 0.463 | 1.07 | 1.02–1.11 | 0.002 |
| Retired, n (%) | 8,881 (69.3) | 7,952 (69.9) | 1.01 | 0.97–1.06 | 0.509 | 0.86 | 0.81–0.92 | <0.001 |
| Index insulin source, n (%) | ||||||||
| Human insulin | 6,494 (50.6) | 6,053 (53.2) | 1 (reference) | 1 (reference) | ||||
| Insulin analog | 5,445 (42.5) | 4,016 (35.3) | 0.84 | 0.81–0.87 | <0.001 | 0.88 | 0.85–0.92 | <0.001 |
| Animal-derived insulin | 884 (6.9) | 1,300 (11.4) | 1.27 | 1.19–1.34 | <0.001 | 1.01 | 0.89–1.16 | 0.860 |
| Index insulin action profile, n (%) | ||||||||
| Prandial insulin | 1,099 (8.6) | 1,529 (13.4) | 1.31 | 1.24–1.38 | <0.001 | 1.24 | 1.09–1.40 | 0.001 |
| Basal insulin | 1,612 (12.6) | 1,253 (11.0) | 0.92 | 0.87–0.98 | 0.010 | 0.98 | 0.92–1.05 | 0.539 |
| Premixed insulin | 10,112 (78.9) | 8,587 (75.5) | 1 (reference) | 1 (reference) | ||||
| Count of A1c tests, mean (SD) | 0.39 (0.67) | 0.27 (0.60) | 0.77 | 0.75–0.80 | <0.001 | 0.81 | 0.78–0.84 | <0.001 |
| Any claims-based hypoglycemia events, n (%) | 79 (0.6) | 122 (1.1) | 1.50 | 1.26–1.80 | <0.001 | 1.44 | 1.20–1.74 | <0.001 |
| Comorbidities and complications | ||||||||
| CCI, mean (SD) | 1.79 (1.34) | 2.19 (1.52) | 1.13 | 1.12–1.14 | <0.001 | 1.01 | 0.99–1.02 | 0.228 |
| Hypertension, n (%) | 5,063 (39.5) | 6,976 (61.4) | 1.97 | 1.90–2.05 | <0.001 | 1.80 | 1.71–1.88 | <0.001 |
| Dyslipidemia, n (%) | 2,750 (21.4) | 3,590 (31.6) | 1.48 | 1.43–1.54 | <0.001 | 1.19 | 1.14–1.25 | <0.001 |
| Retinopathy, n (%) | 2,156 (16.8) | 1,901 (16.7) | 1.00 | 0.95–1.05 | 0.985 | 1.04 | 0.99–1.10 | 0.142 |
| Neuropathy, n (%) | 3,483 (27.2) | 2,096 (18.4) | 0.68 | 0.65–0.71 | <0.001 | 0.81 | 0.77–0.85 | <0.001 |
| Nephropathy, n (%) | 2,616 (20.4) | 1,551 (13.6) | 0.69 | 0.65–0.72 | <0.001 | 0.77 | 0.73–0.82 | <0.001 |
| Count of unique OAD drug classes, mean (SD) | 2.38 (1.29) | 2.05 (1.28) | 0.86 | 0.85–0.87 | <0.001 | 0.86 | 0.84–0.87 | <0.001 |
| Any hospitalizations, n (%) | 2,824 (22.0) | 2,653 (23.3) | 0.98 | 0.94–1.03 | 0.455 | 0.64 | 0.60–0.68 | <0.001 |
| Direct medical cost ($), mean (SD) | 798 (1,456) | 898 (1,532) | 1.14 | 1.12–1.16 | <0.001 | 1.16 | 1.14–1.18 | <0.001 |
Note: HR >1 indicates that patients were less likely to be persistent than the reference group.
Abbreviations: SD, standard deviation; HR, hazard ratio; CI, confidence interval; CCI, Charlson Comorbidity Index; OAD, oral antidiabetic medication.