Laboratory test utilisation rates before and after intervention programmes
| GPs | Comparison doctors | |||||||
| Tests per year (per GP) | Percentage change (95% CI) | Tests per year (per doctor) | Percentage change (95% CI) | |||||
| Laboratory test | Before | After | p Value* | Before | After | p Value* | ||
| C-reactive protein | 27 7403 (87.8) | 452 322 (143.1) | <0.01 | 63 (59 to 67) | 73 674 (30.4) | 89 449 (36.9) | <0.01 | 21 (11 to 31) |
| Erythrocyte sedimentation rate | 599 096 (189.5) | 239 655 (75.8) | <0.01 | −60 (−67 to −62) | 137 642 (56.8) | 113 116 (46.7) | <0.01 | −18 (−23 to −12) |
| Thyroid-stimulating hormone | 702 032 (223.6) | 675 810 (215.2) | <0.01 | −4 (−5 to −2) | 82 470 (33.8) | 78 188 (32.0) | 0.11 | − 5 (−12 to 1) |
| Free thyroxine 4 | 452 934 (144.2) | 253 374 (80.7) | <0.01 | −44 (−47 to −41) | 71 141 (29.1) | 61 825 (25.3) | <0.01 | −13 (−19 to −7) |
| Free thyroxine 3 | 130 710 (41.6) | 83 610 (26.6) | <0.01 | −36 (−41 to −31) | 26 939 (11.0) | 23 016 (9.4) | <0.01 | −15 (−23 to −6) |
| Culture | 137 081 (41.1) | 93 872 (28.1) | <0.01 | −32 (−34 to −29) | 11 205 (4.1) | 8384 (3.0) | <0.01 | −25 (−33 to −17) |
| Giardia and Cryptosporidium | 84 944 (25.5) | 58 203 (17.5) | <0.01 | −31 (−34 to −29) | 6917 (2.5) | 5460 (2.0) | <0.01 | −21 (−30 to −12) |
| Ova and parasites | 62 594 (18.8) | 26 953 (8.1) | <0.01 | −57 (−62 to −52) | 5393 (1.9) | 3084 (1.1) | <0.01 | −43 (−58 to −28) |
| Patients per year (per GP) | Patients per year (per doctor) | |||||||
| C-reactive protein | 189 291 (59.9) | 331 296 (104.8) | <0.01 | 75 (71 to 79) | 33 185 (13.7) | 42 113 (17.4) | <0.01 | 27 (19 to 35) |
| Erythrocyte sedimentation rate | 398 290 (126.0) | 161 375 (51.1) | <0.01 | −59 (−62 to −57) | 66 724 (27.5) | 56 582 (23.3) | <0.01 | −15 (−20 to −10) |
| Thyroid-stimulating hormone | 522 768 (166.5) | 528 296 (168.2) | 0.20 | 1 (−1 to 3) | 58 045 (23.8) | 57 661 (23.6) | 0.85 | −1 (−8 to 6) |
| Free thyroxine 4 | 327 471 (104.3) | 182 117 (58.0) | <0.01 | −44 (−47 to −41) | 49 117 (20.1) | 44 232 (18.1) | <0.01 | −10 (−16 to −4) |
| Free thyroxine 3 | 90 775 (28.9) | 58 156 (18.5) | <0.01 | −36 (−41 to −31) | 16 656 (6.8) | 14 849 (6.1) | 0.01 | −11 (−19 to −3) |
| Culture | 79 079 (23.7) | 67 256 (20.2) | <0.01 | −15 (−17 to −13) | 6371 (2.3) | 5645 (2.0) | <0.01 | −11 (−19 to −4) |
| Giardia and Cryptosporidium | 49 900 (15.0) | 42 252 (12.7) | <0.01 | −15 (−18 to −13) | 3933 (1.4) | 3693 (1.3) | 0.20 | −6 (−15 to 3) |
| Ova and parasites | 33 395 (10.0) | 18 743 (5.6) | <0.01 | −44 (−48 to −40) | 2719 (1.0) | 1909 (0.7) | <0.01 | −30 (−43 to −16) |
↵* Probability of a difference in the mean number of tests or patients per physician per year before and after intervention programmes.