Table 1.
Summary of study population (THIN database) by practice and patient-level characteristics
| Practice characteristics | |
| Number of general practices | 430 |
| General practice sizea, median [IQR] | 241 [150–351] |
| Location, N (%) | |
| England | 322 (75) |
| Northern Ireland | 21 (5) |
| Scotland | 56 (13) |
| Wales | 31 (7) |
| Patient characteristics | |
| Number of patients | 112,633 |
| Age, median [IQR] | 70 [60–78] |
| Sex (male), N (%) | 61,944 (55) |
| Location, N (%) | |
| England | 88,838 (79) |
| Northern Ireland | 3464 (3) |
| Scotland | 12,461 (11) |
| Wales | 7870 (7) |
| Deprivation quintiles, N (%) | |
| 1 (most affluent) | 23,853 (21) |
| 2 | 23,106 (21) |
| 3 | 23,031 (20) |
| 4 | 22,054 (20) |
| 5 (most deprived) | 16,352 (15) |
| Unknown | 4237 (4) |
| Clinical measures | |
| HbA1c (%), median [IQR] | 7.05 [6.4–7.9] |
| HbA1c (%), mean (SD) | 7.35 (1.41) |
| Systolic blood pressure (mmHg), mean (SD) | 134 (16) |
| Diastolic blood pressure (mmHg), mean (SD) | 75 (10) |
| BMI (kg/m2), median [IQR] | 29.8 [26.4–34.1] |
| Total cholesterol (mmol/L), median [IQR] | 4.1 [3.5–4.7] |
| HDL cholesterol (mmol/L), median [IQR] | 1.19 [1.00–1.40] |
| Medication, N (%) | |
| Insulin | 66,530 (59.1) |
| Other hypoglycaemic medication | 33,061 (29.4) |
| Clinical outcomes, N (%) | |
| Atrial fibrillation | 1101 (1.058) |
| Chronic kidney disease | 381 (0.349) |
| Chronic obstructive pulmonary disease | 846 (0.801) |
| Ischaemic heart disease | 967 (1.109) |
| Peripheral vascular disease | 575 (0.545) |
| Stroke | 458 (0.426) |
BMI body mass index, HbA1c glycosylated haemoglobin, HDL high-density lipoprotein, IQR interquartile range, SD standard deviation. Note: the percentage corresponds to the number of applicable patients, and so the total may not be identical for each outcome variable. aHere general practice size corresponds to the number of patients within the general practice who have satisfied the entry criteria (patients who had C10F Read (version 2) code for diabetes entered on the Vision GP patient management system or other codes specifying type-2 diabetes)