Table 4.
Cost effectiveness (relative to no intervention) in order of QALYs gained of strategies relevant to policy or on the “cost effectiveness frontier” (see fig 2 for explanation)
| Strategy | Intervention for each maternal risk group | Cost (£m) | QALYs gained | Expected net benefit (£m)* | Antibiotic exposure (% of population) | % of infections prevented (%)† | Comment | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | |||||||
| RCOG guidelines | N | I | I | I | N | N | N | I | I | I | N | N | −1.2 | 340 | 9.7 | 5.2 | 5.3 | — |
| Current best practice | N | I | I | I | O | N | N | I | I | I | N | N | −2.9 | 741 | 21.4 | 7.4 | 10.1 | Control arm for proposed HTA trial |
| HTA trial intervention | N | C | C | C | C | C | N | C | C | C | C | C | 2.29 | 959 | 21.7 | 10.7 | 16.4 | Intervention arm for proposed HTA trial |
| Treat groups 1-6, 8-10 | I | I | I | I | O | I | N | I | I | I | N | N | −4.5 | 1224 | 35.1 | 11.0 | 15.9 | Optimal non-testing strategy minimising antibiotics |
| Treat groups 1-10 | O | I | I | I | O | I | O | O | O | I | N | N | −4.8 | 1217 | 35.2 | 17.8 | 15.6 | On cost effectiveness frontier |
| Treat groups 1-10 | I | I | I | I | O | I | O | I | I | I | N | N | −4.7 | 1285 | 36.8 | 19.0 | 16.7 | On cost effectiveness frontier |
| Culture test groups 7, 11, 12; treat groups 1-6, 8-10 | I | I | I | I | O | I | C | I | I | I | C | C | −0.6 | 1836 | 46.5 | 20.7 | 27.4 | Optimal testing strategy minimising antibiotics |
| Culture test groups 11, 12; treat groups 1-10 | I | I | I | I | O | I | O | I | I | I | C | C | −1.3 | 1870 | 48.1 | 27.7 | 27.9 | On cost effectiveness frontier |
| Culture test groups 11, 12; treat groups 1-10 | I | I | I | I | I | I | O | I | I | I | C | C | −1.1 | 1897 | 48.5 | 27.4 | 27.9 | Maximum net benefit |
| PCR test groups 11, 12; treat groups 1-10 | I | I | I | I | I | I | O | I | I | I | P | P | 2.1 | 1958 | 46.8 | 27.1 | 29.1 | On cost effectiveness frontier |
| PCR test groups 11, 12; treat groups 1-10 | I | I | I | I | I | I | I | I | I | I | P | P | 2.9 | 1965 | 46.2 | 27.1 | 29.3 | On cost effectiveness frontier |
RCOG=Royal College of Obstetricians and Gynaecologists; HTA=Health Technology Assessment; N=no intervention; I=treat with intravenous penicillin without testing; C=test by culture at 35-37 weeks, and treat positive cases with intravenous penicillin; O=treat with oral erythromycin without testing; P=test by polymerase chain reaction, and treat positive cases with intravenous penicillin.
*Calculated assuming 680 000 deliveries annually and a “willingness to pay” threshold of £25 000 per QALY. Net benefit is equal to the QALYs gained multiplied by threshold value (£25 000) minus the costs of the strategy.
†Stillbirths and live births with early or late onset infection.