Table 1.
Study cohort characteristics
| Characteristics | DM1 patients (N=1,061) | DM1-free subjects (N=15,119) |
|---|---|---|
|
| ||
| N (%) | N (%) | |
| Follow-up (person-years) | 8054.3 | 82400.4 |
| Age at start of follow-up, year | ||
| ≤20 | 155 (14.6%) | 2446 (16.2%) |
| >20, ≤30 | 207 (19.5%) | 3609 (23.9%) |
| >30, ≤40 | 210 (19.8%) | 3068 (20.3%) |
| >40, ≤50 | 206 (19.4%) | 2729 (18.0%) |
| >50 | 283 (26.7%) | 3267 (21.6%) |
| Age at 1st DM diagnosis in CPRD, year | ||
| ≤15 | 191 (18.0%) | |
| >15, ≤30 | 286 (27.0%) | |
| >30, ≤45 | 285 (26.9%) | |
| >45, ≤60 | 225 (21.2%) | |
| >60 | 74 (7.0%) | |
| Gender | ||
| Male | 520 (49.0%) | 7350 (48.6%) |
| Female | 541 (51.0%) | 7769 (51.4%) |
| Year at registration to the practice | ||
| Before 1991 | 336 (31.7%) | 4239 (28.0%) |
| 1991–2000 | 293 (27.6%) | 4689 (31.0%) |
| After 2000 | 432 (40.7%) | 6191 (40.9%) |
| Practice located in England | 844 (79.5%) | 12346 (81.7%) |
| UK Region of included practices1 | ||
| North | 370 (34.9%) | 5079 (33.6%) |
| Central | 340 (32.0%) | 4701 (31.1%) |
| South | 351 (33.1%) | 5339 (35.3%) |
| Socioeconomic status2 based on practice location, quintile | ||
| 1 (Most affluent) | 158 (14.9%) | 2206 (14.6%) |
| 2 | 181 (17.1%) | 2467 (16.3%) |
| 3 | 196 (18.5%) | 2795 (18.5%) |
| 4 | 221 (20.8%) | 3175 (21.0%) |
| 5 | 305 (28.7%) | 4476 (29.6%) |
| Average Annual number of practice visit3 | ||
| 0–1 | 187 (17.6%) | 6049 (40.0%) |
| >1, ≤5 | 224 (21.1%) | 4295 (28.4%) |
| >5 | 650 (61.3%) | 4775 (31.6%) |
1
North: North West England, Yorkshire & The Humbler, Northern Ireland, North East England, and Scotland
Central: East of England, Wales, West Midlands, and East Midlands
South: South West England, South East Coast, South Central England and London
2
Using practice level Indices of Multiple Deprivation data
3
Average number of clinic visit/year after the start date until 1 year prior to the end of follow-up