TABLE 1.
Demographic and Clinical Characteristics at Baseline of the Matched Cohorts, by Persistence with MDI During 1 Post-Index Year as Determined Using Method 2a
| Persistent with MDI (n = 2,723) | Nonpersistent with MDI (n = 8,169) | SMDb | P Valuec | |
|---|---|---|---|---|
| Male, n (%) | 1,577 (57.9) | 4,651 (56.9) | 0.0198 | 0.37 |
| Age at index date, mean (SD) | 52.6 (7.8) | 52.5 (7.9) | 0.0028 | 0.90 |
| 18-34 years, n (%) | 69 (2.5) | 258 (3.2) | 0.29 | |
| 35-44 years, n (%) | 372 (13.7) | 1,054 (12.9) | ||
| 45-54 years, n (%) | 973 (35.7) | 2,890 (35.4) | ||
| 55-64 years, n (%) | 1,309 (48.1) | 3,967 (48.6) | ||
| Geographic region, n (%) | 0.97 | |||
| Northeast | 324 (11.9) | 956 (11.7) | 0.0059 | |
| North Central | 693 (25.4) | 2,109 (25.8) | 0.0084 | |
| South | 1,090 (40.0) | 3,281 (40.2) | 0.0027 | |
| West | 616 (22.6) | 1,823 (22.3) | 0.0075 | |
| Insurance plan type, n (%) | 0.83 | |||
| HMO | 538 (19.8) | 1,575 (19.3) | 0.0123 | |
| PPO | 1,540 (56.6) | 4,669 (57.2) | 0.0122 | |
| Other | 645 (23.7) | 1,925 (23.6) | 0.0029 | |
| CCI, median (IQR) | 1 (1-3) | 1 (1-3) | 0.0073 | 0.74 |
| 0, n (%) | 245 (9.0) | 738 (9.0) | 0.99 | |
| 1, n (%) | 1,418 (52.1) | 4,271 (52.3) | ||
| 2, n (%) | 367 (13.5) | 1,107 (13.6) | ||
| ≥ 3, n (%) | 693 (25.5) | 2,053 (25.1) | ||
| Comorbidity/complication, n (%) | ||||
| Hypertension | 1,494 (54.9) | 4,444 (54.4) | 0.0093 | 0.67 |
| Disorder of lipid metabolism | 1,396 (51.3) | 4,125 (50.5) | 0.0155 | 0.49 |
| Ischemic heart disease | 438 (16.1) | 1,315 (16.1) | 0.0003 | 0.99 |
| Obesity | 384 (14.1) | 1,136 (13.9) | 0.0057 | 0.80 |
| Renal disease | 347 (12.7) | 1,026 (12.6) | 0.0055 | 0.80 |
| Neuropathy | 325 (11.9) | 982 (12.0) | 0.0026 | 0.91 |
| Retinopathy | 233 (8.6) | 692 (8.5) | 0.0030 | 0.89 |
| Stroke | 88 (3.2) | 256 (3.1) | 0.0052 | 0.80 |
| Acute myocardial infarction | 71 (2.6) | 221 (2.7) | 0.0057 | 0.78 |
| Hypoglycemia | 18 (0.7) | 53 (0.7) | 0.0016 | 0.95 |
aPersistence was defined as the presence of 1 or more claims for both basal insulin and bolus insulin every quarter (90 days) for 4 consecutive quarters of the post-index year.
bA standardized mean difference < 0.10 indicates sufficient balance between matched cohorts.
cThe chi-square test was used for categorical variables and the t-test for continuous/count variables to compare persistent versus nonpersistent cohorts.
CCI = Charlson Comorbidity Index; HMO = health maintenance organization; IQR = interquartile range; MDI = multiple daily insulin injections; PPO = preferred provider organization; SMD = standardized mean difference; SD = standard deviation.