| Characteristic | Total | Intervention group | ||
|---|---|---|---|---|
| Strategy 1(GP only) | Strategy 2(GP and patient) | P value | ||
| Health centres, n | 26 | 13 | 13 | |
| GPs,n | 158 | 78 | 80 | 0.85 |
| Male, n (%) | 47 (30) | 25 (32) | 22 (28) | 0.72 |
| Population, n | 195 394 | 97 658 | 97 736 | 0.99 |
| SES, mean (range)a | 0.26(−2.58–2.06) | 0.53(−2.40–2.06) | 0.21(−2.58–1.66) | 0.48 |
| Vitamin D tests pre-intervention, n | 17 527 | 10 277 | 7250 | 0.30 |
| Vitamin D/1000 patients pre-intervention, n (range) | 88 (12–262) | 102 (32–262) | 75(12–150) | 0.22 |
| Vitamin B12 tests pre-intervention, n | 12 304 | 7242 | 5062 | 0.36 |
| Vitamin B12/1000 patients pre-intervention, n (range) | 59 (7–198)b | 69 (7–198) | 49 (15–156) | 0.21 |
| GPs who followed e-learning, n (%) | 76 (48) | 28 (36) | 48 (60) | 0.11 |
| GPs present at first training session, n (%) | 50 (32) | 26 (33) | 24 (30) | 0.86 |
| GPs present at second training session, n (%) | 50 (32) | 24 (31) | 26 (33) | 0.85 |
aSES data, linked by four digital postal codes to location of health centre.17 bMean difference Utrecht-Rotterdam = –60 (95% CI = –94 to –26), P = 0.06. SES = socioeconomic status.