Stillbirth and early neonatal mortality rates may be underestimated using recall information: A comparison of demographic surveillance methodologies.

OBJECTIVE: Child mortality and stillbirth rates (SBR) remain high in low-income countries but may be underestimated due to incomplete reporting of child deaths in retrospective pregnancy/birth histories. The aim of this study is to compare stillbirth and mortality estimates derived using two different methods: the method assuming full information and the prospective method. METHODS: Bandim Health Project's Health and Demographic Surveillance Systems (HDSS) follows women of reproductive age and children under five through routine home visits every 1, 2 or 6 months. Between 2012 and 2020, we estimated and compared early neonatal (ENMR, <7 days), neonatal (NMR, <28 days), and infant mortality (IMR, <1 year) per 1000 live births and SBR per 1000 births. Risk time for children born to registered women was calculated from birth (the method assuming full information) versus date of first observation in the HDSS (the prospective method), either at birth (for pregnancy registration) or registration. Rates were calculated using the Kaplan-Meier estimator and compared in generalised linear models allowing for within-child correlation obtaining relative risks (RR). RESULTS: We registered and followed 29,413 infants (1380 deaths; 1459 stillbirths) prospectively. An additional 164 infant deaths and 129 stillbirths were registered retrospectively and included in the method assuming full information. The ENMR was 24.5 (95%CI: 22.6-26.4) for the method assuming full information and 25.8 (23.7-27.8) for the prospective method, RR = 0.96 (0.93-0.99). Differences were smaller for the NMRs and IMRs. For SBRs, the estimates were 53.5 (50.9-56.0) and 58.6 (55.7-61.5); RR = 0.91 (0.90-0.93). The difference between methods became more pronounced when the analysis was limited to areas visited every 6 months: RR for ENMR: 0.91 (0.86-0.96) and RR for SBR: 0.85 (0.83-0.87). CONCLUSIONS: Assuming full information underestimates SBR and ENMR. Accounting for omissions of stillbirths and early neonatal deaths may lead to more accurate estimates and improved ability to monitor mortality.

Retesting the hypothesis that early Diphtheria-Tetanus-Pertussis vaccination increases female mortality: An observational study within a randomised trial.

BACKGROUND: There are worrying indications that diphtheria-tetanus-pertussis (DTP) vaccine has negative non-specific effects for females. We previously found, in a trial of early-Bacillus Calmette-Guérin (BCG) to low weight (LW) neonates, that receiving early-DTP (before 2 months of age), was associated with increased female mortality compared with no-DTP/delayed-DTP. Within a subsequent LW trial, we aimed to retest this observation. METHODS: Between 2010 and 2014, in Guinea-Bissau, 2,398 infants were randomised 1:1 to early-BCG (intervention) or delayed-BCG (standard practice for LW neonates) and visited at 2, 6 and 12 months of age to assess nutritional and vaccination status. DTP is recommended at 6 weeks of age. We examined the effect of having "early-DTP" versus "no-DTP" at the time of the 2-month visit on all-cause mortality between the 2- and 6-month visits in Cox models stratified by sex and adjusted for BCG-group and 2-month-weight-for-age (z-scores) providing adjusted mortality rate ratios (aMRRs). We analysed to which extent conditions varied between the present and the previous LW trials and how that might have affected the overall result of comparing the early-DTP and the no-DTP groups. RESULTS: At the time of the 2-month visit, 75% (1,795/2,398) had received DTP. Those vaccinated had better anthropometric indices than no-DTP infants at birth and by 2 months of age. Between the 2- and 6-month visits, 29 deaths occurred. The early-DTP/no-DTP aMRR was 1.09 (95% CI: 0.44-2.69); 1.19 (0.45-3.15) for females and 0.77 (0.14-4.19) for males. Compared to the previous study, the present study cohort had 56% (30-72%) lower overall mortality, fewer no-DTP infants, higher BCG vaccination coverage and several more oral polio vaccine campaigns. CONCLUSION: We did not find that early-DTP was associated with increased female mortality as found in a previous study; differences in results may partly be due to a decline in overall mortality and changes in vaccination practices.