From: Sudden infant death syndrome: a re-examination of temporal trends
Kitagawa decomposition – traditional method (per 10,000 live births) | ||||||
---|---|---|---|---|---|---|
Plurality and gestational age (weeks) | Contribution of changes in gestational age distribution | Contribution of changes in gestational age-specific SIDS rate | Sum of both components (overall decline) | Relative contribution of changes in gestational age distribution (%) | Relative contribution of changes in gestational age- specific SIDS rate (%) | Sum of both components (%) |
Singletons | ||||||
22-36 weeks | +0.18 | −0.63 | −0.45 | +40.0 | −140.0 | 100 |
≥37 weeks | +0.19 | −2.46 | −2.27 | +8.4 | −108.4 | 100 |
Total | +0.37 | −3.09 | −2.72 | +13.6 | −113.6 | 100 |
Twins | ||||||
22-36 weeks | +1.29 | −3.09 | −1.81 | +71.3 | −171.3 | 100 |
≥37 weeks | −0.98 | −0.82 | −1.80 | −54.3 | −45.7 | 100 |
Total | +0.31 | −3.92 | −3.61 | +8.6 | −108.6 | 100 |
Modified Kitagawa decomposition (per 10,000 fetuses-at-risk) | ||||||
Singletons | ||||||
22-36 weeks | <0.01 | −0.44 | −0.44 | <0.0 | −100.0 | 100 |
≥37 weeks | −1.22 | −1.04 | −2.26 | −54.0 | −46.0 | 100 |
Total | −1.22 | −1.48 | −2.70 | −45.2 | −54.8 | 100 |
Twins | ||||||
22-36 weeks | −0.35 | −1.42 | −1.77 | −19.7 | −80.3 | 100 |
≥37 weeks | −1.90 | +0.13 | −1.77 | −107.2 | +7.2 | 100 |
Total | −2.25 | −1.29 | −3.54 | −63.5 | −36.5 | 100 |