Practice- and Patient-Level Characteristics
| Characteristic | Intervention Trial Arm | Control Trial Arm |
|---|---|---|
| Family practices | ||
| Number of family practices | 50 | 50 |
| Mean eligible participants aged 18–59 y, No. | 4,132 | 3,547 |
| Distribution by region, No. (%)a | ||
| London | 8 (16) | 9 (18) |
| Midlands | 9 (18) | 8 (16) |
| North | 9 (18) | 8 (16) |
| South and East | 13 (26) | 13 (26) |
| South West | 8 (16) | 8 (16) |
| Scotland | 3 (6) | 4 (8) |
| Distribution by start date, No. (%) | ||
| December 2010 | 14 (28) | 17 (34) |
| January 2011 | 19 (38) | 17 (34) |
| March 2011 | 15 (30) | 15 (30) |
| April 2011 | 2 (4) | 1 (2) |
| Patients | ||
| Eligible patients aged 18–59 y, No. | ||
| 12-Month preintervention period | 292,398 | 264,137 |
| 12-Month intervention period | 294,929 | 263,895 |
| Person years analyzed, No. | ||
| 12-Month preintervention period | 270,437 | 251,994 |
| 12-Month intervention period | 283,776 | 234,373 |
| Female patients, No. (%) | ||
| 12-Month preintervention period | 145,116 (50) | 132,375 (50) |
| 12-Month intervention period | 147,199 (50) | 132,378 (50) |
| Patients aged 45–59 y, No. (%) | ||
| 12-Month preintervention period | 102,743 (35) | 94,194 (36) |
| 12-Month intervention period | 102,317 (35) | 93,850 (36) |
↵a Midlands includes East and West Midlands; North includes North East, North West, Yorkshire, and Humberside; South and East includes South Central, South East, and East Anglia.