Table 1.
Baseline characteristics before and after PS overlap weighting in individuals with T1D (n = 8,533)
| T1D | Unweighted | Overlap weighted | ||||
|---|---|---|---|---|---|---|
| Nonusers (n = 3,518) | CGM users (n = 5,015) | SMD | Nonusers (n = 3,518) | CGM users (n = 5,015) | SMD | |
| Index year, % | 0.546 | <0.001 | ||||
| 2015 | 19.9 | 8.3 | 10.0 | 10.0 | ||
| 2016 | 18.1 | 10.5 | 12.4 | 12.4 | ||
| 2017 | 17.2 | 11.3 | 13.9 | 13.9 | ||
| 2018 | 17.3 | 23.0 | 18.7 | 18.7 | ||
| 2019 | 15.2 | 25.7 | 21.5 | 21.5 | ||
| 2020 | 12.4 | 21.2 | 23.5 | 23.5 | ||
| Mean (SD) age at index, years | 64.5 (11.7) | 59.4 (11.3) | 0.438 | 61.7 (11.6) | 61.7 (11.3) | <0.001 |
| Male sex, % | 95.3 | 91.4 | 0.156 | 93.5 | 93.5 | <0.001 |
| Mean (SD) BMI, kg/m2 | 28.5 (6.20) | 28.0 (5.1) | 0.094 | 27.7 (5.9) | 27.7 (5.3) | <0.001 |
| Ethnicity, % | 0.231 | <0.001 | ||||
| White, non-Hispanic | 73.8 | 83.2 | 79.7 | 79.7 | ||
| African American | 20.5 | 12.8 | 15.3 | 15.3 | ||
| White, Hispanic | 4.1 | 3.0 | 3.5 | 3.5 | ||
| Other | 1.6 | 1.1 | 1.5 | 1.5 | ||
| U.S. region, % of total | 0.029 | <0.001 | ||||
| South | 40.5 | 39.4 | 38.5 | 38.5 | ||
| Midwest | 24.6 | 25.5 | 24.0 | 24.0 | ||
| West | 22.6 | 23.2 | 26.0 | 26.0 | ||
| Northeast | 12.3 | 11.9 | 11.4 | 11.4 | ||
| Endocrinologist visit, % | 34.8 | 91.1 | 1.435 | 72.1 | 72.1 | <0.001 |
| Median (IQR) total PCP and endocrine visits | 3 (2, 6) | 6 (4, 9) | 0.610 | 5 (3, 8) | 5 (3, 8) | <0.001 |
| Mean (SD) LDL cholesterol, mg/dL | 85 (33) | 86 (32) | 0.040 | 86 (34) | 86 (32) | <0.001 |
| Mean (SD) HDL cholesterol, mg/dL | 49 (16) | 55(16) | 0.338 | 53 (17) | 53(16) | <0.001 |
| Mean (SD) total cholesterol, mg/dL | 159 (41) | 162 (40) | 0.073 | 161 (42) | 161 (40) | <0.001 |
| Median (IQR) triglycerides, mg/dL | 100 (69, 152) | 84 (60, 124) | 0.220 | 91 (64, 139) | 88 (63, 133) | <0.001 |
| Mean (SD) SBP, mmHg | 134 (15) | 133 (14) | 0.137 | 133 (14) | 134 (14) | 0.020 |
| Mean (SD) DBP, mmHg | 74 (9) | 75 (8) | 0.066 | 75 (8) | 74 (8) | 0.039 |
| Median (IQR) creatinine, mg/dL | 1.1 (0.9, 1.3) | 1.0 (0.9, 1.2) | 0.152 | 1.0 (0.9, 1.3) | 1.0 (0.9, 1.3) | <0.001 |
| Mean (SD) eGFR, mL/min/1.73 m2 | 73 (25) | 78 (23) | 0.202 | 75 (25) | 75 (24) | <0.001 |
| Mean (SD) HbA1c, % | 8.2 (1.6) | 8.4 (1.4) | 0.102 | 8.5 (1.6) | 8.5 (1.4) | 0.019 |
| Mean (SD) HbA1c, mmol/mol | 66 (17.5) | 68 (15.3) | 0.102 | 69 (17.5) | 69 (15.3) | 0.019 |
| Any insulin use, % | 100.0 | 100.0 | <0.001 | 100.0 | 100.0 | <0.001 |
| Dual basal and bolus use | 81.5 | 67.1 | 0.334 | 79.3 | 77.9 | 0.034 |
| Basal use only | 10.3 | 0.7 | 0.427 | 2.2 | 2.2 | 0.004 |
| NPH insulin | 10.0 | 3.3 | 0.273 | 4.0 | 4.0 | <0.001 |
| Long/basal insulin | 76.4 | 66.4 | 0.222 | 78.2 | 78.2 | <0.001 |
| Mixed insulin | 8.8 | 1.4 | 0.342 | 2.0 | 2.0 | <0.001 |
| Short/rapid insulin | 89.7 | 99.3 | 0.427 | 97.8 | 97.8 | 0.004 |
| Insulin pump use, % | 5.6 | 49.7 | 1.134 | 18.8 | 18.8 | <0.001 |
| Glucagon, % | 10.9 | 33.6 | 0.568 | 21.4 | 21.4 | <0.001 |
| Statin use, % | 71.4 | 75.9 | 0.102 | 75.1 | 75.1 | <0.001 |
| Antihypertensive medication use, % | 77.7 | 69.5 | 0.188 | 74.0 | 74.0 | <0.001 |
| Hypoglycemic risk score | 0.132 | <0.001 | ||||
| Low | 71.1 | 76.3 | 72.9 | 72.9 | ||
| Intermediate | 19.2 | 14.4 | 16.6 | 16.6 | ||
| High | 9.6 | 9.3 | 10.5 | 10.5 | ||
| Noninsulin diabetes medication, % | 23.3 | 16.3 | 0.177 | 20.4 | 20.4 | <0.001 |
| Metformin | 20.3 | 13.5 | 0.183 | 16.7 | 16.3 | 0.013 |
| Private insurance, % | 30.6 | 46.4 | 0.329 | 37.0 | 37.0 | <0.001 |
| Medicare, % | 60.3 | 42.3 | 0.366 | 51.6 | 51.6 | <0.001 |
| Medicaid, % | 2.0 | 1.4 | 0.046 | 2.2 | 2.2 | <0.001 |
| Extended care, % | 8.9 | 5.1 | 0.150 | 7.8 | 7.8 | <0.001 |
| Housing insecurity, % | 4.4 | 2.9 | 0.083 | 4.0 | 4.0 | <0.001 |
| Hospice care, % | 0.8 | 0.5 | 0.043 | 0.9 | 0.9 | <0.001 |
| ER visits, % | 0.070 | <0.001 | ||||
| 0 | 78.1 | 75.7 | 75.5 | 75.5 | ||
| 1 | 11.7 | 14.1 | 13.3 | 13.3 | ||
| ≥2 | 10.2 | 10.2 | 11.2 | 11.2 | ||
| Elixhauser comorbidity score, % | 0.111 | 0.024 | ||||
| 0 | 7.7 | 10.3 | 8.1 | 8.1 | ||
| 1 | 24.7 | 25.9 | 23.6 | 24.2 | ||
| 2 | 25.7 | 25.8 | 26.0 | 25.1 | ||
| ≥3 | 41.9 | 37.9 | 42.3 | 42.3 | ||
| DCSI weighted score, % | 0.094 | 0.054 | ||||
| 0 | 25.6 | 21.9 | 22.4 | 22.2 | ||
| 1 | 21.6 | 24.2 | 22.7 | 20.9 | ||
| 2 | 18.4 | 19.0 | 17.3 | 18.9 | ||
| ≥3 | 34.3 | 34.9 | 37.5 | 38.0 | ||
| Hypoglycemia event, % | 3.6 | 3.6 | 0.004 | 4.0 | 4.0 | <0.001 |
| Hypoglycemia event or outpatient glucose <54 mg/dL, % | 9.0 | 9.4 | 0.016 | 9.7 | 9.9 | 0.007 |
| Hyperglycemia event, % | 7.2 | 7.2 | 0.003 | 7.9 | 7.9 | <0.001 |
| Hospitalization, % | 16.6 | 13.6 | 0.083 | 16.0 | 16.0 | <0.001 |
The baseline period is the period before the index date. SMD <0.1 indicates a covariate is balanced between groups. Hypoglycemia and hyperglycemia were identified by ICD-9/10 diagnostic codes from inpatient or ER settings. Hypoglycemia or glucose <54 mg/dL includes diagnoses or outpatient glucose laboratory values <54 mg/dL. Hospitalizations were identified by inpatient admissions. Extended care includes long-term inpatient stays, nursing home consults, or skilled home care consults. The baseline period for events and values is standardized for all participants to 1 year before the index date, except for HbA1c values that are within 6 months before the index date and Elixhauser comorbidity and DCSI weighted scores that are within 24 months before the index date.
DBP, diastolic blood pressure; DCSI, Diabetes Complications Severity Index; eGFR, estimated glomerular filtration rate; IQR, interquartile range; NPH, neutral protamine hagedorn; PCP, primary care provider; SBP, systolic blood pressure.