Summary of findings for the main comparison. Summary of findings table 1.
| Malaria chemoprevention for pregnant women (parity 0‐1) living in endemic areas: maternal outcomes | |||||
| Patient or population: Pregnant women (parity 0‐1) Settings: Malaria‐endemic areas Intervention: Malaria chemoprevention (any regimen) Control: Placebo or no intervention | |||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of participants (trials) | Quality of the evidence (GRADE) | |
| Assumed risk | Corresponding risk | ||||
| Control | Chemoprevention | ||||
| Mortality All‐cause death | 7 per 1000 | 8 per 1000 (3 to 20) | RR 1.15 (0.44 to 3.06) | 2097 (3 trials) | ⊕⊝⊝⊝ very low1,2 |
| Severe anaemia During the third trimester | 145 per 1000 | 87 per 1000 (68 to 108) | RR 0.60 (0.47 to 0.75) | 2503 (3 trials) | ⊕⊕⊕⊕ high3,4,5,6 |
| Anaemia | 649 per 1000 | 539 per 1000 (480 to 604) | RR 0.83 (0.74 to 0.93) | 3662 (5 trials) | ⊕⊕⊕⊕ high3,6,7,8 |
| Uncomplicated clinical malaria | 173 per 1000 | 64 per 1000 (31 to 128) | RR 0.37 (0.18 to 0.74) | 307 (2 trials) | ⊕⊕⊝⊝ low4,9,10 |
| Antenatal parasitaemia | 286 per 1000 | 111 per 1000 (74 to 165) | RR 0.39 (0.26 to 0.58) | 3663 (8 trials) | ⊕⊕⊕⊕ high3,6,7,11 |
| Severe adverse effects12 | ‐ | ‐ | ‐ | ‐ | ‐ |
| *The basis for the assumed risk (eg, the median control group risk across trials) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio. | |||||
| GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate. | |||||
1 Downgraded by 1 for risk of bias: Only one of these trials adequately described allocation concealment to be considered at low risk of selection bias. 2 Downgraded by 2 for imprecision: These trials were not adequately powered to detect a difference in mortality. Only 15 deaths occurred in these three trials.To confidently detect a 25% reduction in maternal mortality in a setting of 350 deaths/100,000 would require a sample size of over 100,000. 3 No serious risk of bias: Exclusion of the trials at high risk of bias did not change the statistical significance or clinical importance of the result. 4 No serious inconsistency: This finding was consistent across all trials and statistical heterogeneity was low. 5 No serious indirectness: These trials were conducted in Kenya and Mozambique between 1996 and 2005, all three trials administered IPT with SP. The definition of severe anaemia was variable; Hb < 8 g/dL, Hb < 7 g/dL, or PCV < 21%. 6 No serious imprecision: This result is statistically significant and the meta‐analysis is adequately powered to detect this effect. 7 No serious inconsistency: Although statistical heterogeneity was high, all trials favoured chemoprevention but there was variability in the size of the effect. 8 No serious indirectness: These trials were conducted in Nigeria, Kenya and Uganda between 1978 and 1999. Three trials administered IPT as SP, one gave weekly chloroquine, and one gave daily proguanil. The definition of anaemia was variable: Hb < 12 g/dL, Hb < 11 g/dL, Hb < 10 g/dL, PCV < 33% and PCV < 30%. 9 Downgraded by 1 for risk of bias. Both trials had high or unclear risk of selection bias and an attrition rate above 20%. 10 Downgraded by 1 for indirectness: Both these trials, from Cameroon 1993 and Mozambique 2002, measured fever history only as proxy for malaria illness. 11 Not downgraded for inconsistency. Despite substantive quantitative heterogeneity (I2 69% across six trials), all show at least a reduction of 23%, often more 11 No serious indirectness: These trials were conducted in The Gambia, Nigeria, Kenya and Mozambique between 1978 and 2005. Five trials gave IPT as SP, one gave pyrimethamine‐dapsone, one pyrimethamine, and one proguanil. 12 Reporting of adverse events was generally poor. No severe adverse events were reported.