TABLE 3.
Sensitivity Analyses to Evaluate the Relationship Between Add-on Treatment and Subject Characteristics
| Analysis Number | Sensitivity Analysis 1 | Sensitivity Analysis 2 | Sensitivity Analysis 3 |
|---|---|---|---|
| Restriction | ≥ 90 Days Metformin Required Before Index HbA1c n = 7,087 | Acceptable Gap for Metformin Limited to 30 Days n = 5,207 | ≥ 0.8 PDC for Metformin Required Before Index HbA1c n = 3,212 |
| Add-on, n (%) | 2,682 (37.8) | 1,982 (38.1) | 1,333 (41.5) |
| No add-on, n (%) | 4,405 (62.2) | 3,225 (61.9) | 1,879 (58.5) |
| Predictors | OR (95% CI) | OR (95% CI) | OR (95% CI) |
| Age 45-64 yearsa | 0.75 (0.57-0.97)c | 0.71 (0.52-0.96)c | 0.69 (0.44-1.09) |
| Age 65-89 yearsa | 0.55 (0.43-0.72)e | 0.53 (0.39-0.72)e | 0.54 (0.35-0.85)d |
| Sex | 1.02 (0.92-1.12) | 1.00 (0.89-1.13) | 1.04 (0.90-1.20) |
| Index HbA1c > 8%-9%b | 2.22 (1.92-2.56)e | 2.09 (1.77-2.47)e | 2.43 (1.94-3.04)e |
| Index HbA1c > 9%-10%b | 2.60 (2.09-3.24)e | 2.64 (2.05-3.42)e | 3.51 (2.35-5.25)e |
| Index HbA1c > 10b | 3.73 (3.08-4.51)e | 3.56 (2.87-4.43)e | 3.58 (2.44-5.24)e |
| Hypertension | 1.53 (1.26-1.85)e | 1.63 (1.30-2.04)e | 1.37 (0.99-1.90) |
| Hyperlipidemia | 1.29 (1.06-1.57)c | 1.24 (0.98-1.55) | 1.07 (0.78-1.48) |
| Obesity | 1.22 (1.08-1.37)d | 1.25 (1.09-1.43)d | 1.20 (1.01-1.43)c |
| Cardiovascular | 1.30 (1.16-1.46)e | 1.37 (1.20-1.56)e | 1.12 (0.95-1.32) |
| Renal | 1.34 (1.20-1.50)e | 1.26 (1.11-1.44)d | 1.27 (1.08-1.49) |
| Ophthalmic | 1.11 (0.99-1.23) | 1.16 (1.02-1.32)c | 1.01 (0.86-1.17) |
Notes: AIC = 8959.31, Hosmer and Lemeshow χ2 = 10.73, P = 0.217.
ICD-9-CM codes for comorbidities: hypertension = 401.xx-405.xx; hyperlipidemia = all 272.xx; obesity = 278.00, 278.01; cardiovascular = 410.xx-417.xx, 420.xx-448.xx, 451.xx-459.xx, 707.xx, 785.4; renal = 580.xx-590.xx, 593.xx; and ophthalmic = 362.xx, 364.41, 364.42, 365.xx-366.xx, 377.xx. ICD-9CM codes in any position were evaluated.
aReference: age 18-44 years.
bReference: HbA1c > 7%-8%.
cModel parameter estimate significant at P < 0.05.
dModel parameter estimate significant at P < 0.01.
eModel parameter estimate significant at P < 0.001.
CI = confidence interval; HbA1c = glycated hemoglobin; ICD-9-CM = International Classification of Diseases, Ninth Revision, Clinical Modification; OR = odds ratio; PDC = proportion of days covered.