Table 2 Application of standardized rules to collective mortality and morbidity outcomes to estimate effect of calcium supplementation during pregnancy on maternal mortality:
Outcome measure | Studies | Total Events | Reduction (Relative risk) | GRADE quality of pooled estimate | Application of standard rules |
|---|---|---|---|---|---|
Cause specific Maternal Mortality | 0 | - | - | - | - |
All cause maternal mortality | (n=1) | 7 | 83% (RR 0.17; 95% CI 0.02, 1.39) | Low | Rule 1: Do not apply < 50 events |
Eclampsia | (n=1) | 42 | 32% reduction (RR 0.68; 95% CI 0.37, 1.26) | Low | Rule 3: Do not apply < 50 events |
Severe gestational hypertensive related morbidity/mortality* | (n=1) | 376 | 20 % (RR 0.80; 95 % CI 0.70-0.91) | Moderate (→ low) | Rule 3 applies “ If there is low- or very low-quality evidence of effect on cause-specific mortality, An d there is high- or moderate-quality evidence of effect on serious morbidity… Then use the smaller of the two effects.” [47] |
Severe Pre-eclampsia | (n=3) | 93 | 30% (RR 0.70; 95% CI 0.46, 1.05) | moderate | |
Pre-eclampsia | (n=10) | 558 | 59 % (RR=0.41; 95% CI 0.24-0.69) | High |