Completed projects have provided an important background for the currently ongoing projects, and have given rise to some of the questions we are currently working with.
Measuring early neonatal mortality in low-income countries
How accurate is the information based on which we evaluate mortality changes?
Andreas Møller Jensen, MSc Mathematics, PhD
Child mortality has during the past 20 years decreased markedly in low-income countries especially after the first month of life. Thus, the early neonatal mortality (first 4 weeks of life) is carrying an increasing burden of the child mortality. To prioritise the right interventions to lower neonatal mortality, accurate data are crucial.
In his PhD, Andreas investigated associations between data collection methods and obtained estimates for neonatal mortality and stillbirth rates, in terms of magnitude, precision and timing.
Andreas’ work builds on Health and Demographic Surveillance system (HDSS). Using demographic surveillance data for almost 30,000 births between 2012 and 2020, Andreas compares the estimated mortality burden assuming full information (counting all children born to women in the HDSS from the date of birth) with the prospective estimates (counting from the date of registration). He shows that early child mortality was significantly underestimated when assuming that full information could be obtained: early neonatal mortality by 4% and the stillbirth rate by 9%. In villages with the least frequent visits (6 months intervals), the underestimations were 9% (early neonatal mortality) and 15% (stillbirth rates). The paper can be found here.
In another study, Andreas linked retrospectively obtained information on births (using a Demographic Health Survey methodology) to HDSS reported births. Comparing the reported date of birth with HDSS data showed that 9% of the reported survey births differed from the recorded month or year of birth in HDSS data. The date of birth of children who were dead at time of the interview was more likely to be displaced compared with children who were alive at time of the interview. More than 60% of the reported age at death differed from the recorded age in the HDSS data.
In conclusion, retrospectively collected information underestimates the levels of stillbirth and early neonatal mortality and registered births and (even more so) deaths are commonly misplaced in calendar time.
Andreas defended his PhD dissertation in May 2023. His research profile and publication list are available here.
Real-life effects of measles vaccination campaigns
Do they improve child health beyond measles immunity?
Anshu Varma, cand.scient.san.publ, PhD
In the last decades, numerous measles vaccination campaigns have been implemented to control and eventually eradicate measles worldwide. During the same decades, mortality in children aged under-five has decreased tremendously.
Meanwhile, accumulating evidence suggests that the measles vaccine protects against other infections than measles. Thus, measles vaccine campaigns may have efficiently contributed to decreasing the under-five child mortality beyond our common understanding.
No trials have studied the potential beneficial non-specific-effects of a measles vaccine campaign.
In a cluster-randomized trial, Anshu evaluated a measles vaccine campaign, by studying its short-term and long-term effect on mortality and morbidity due to any cause in rural Guinea-Bissau, where measles infection is rare and measles vaccine campaigns are still implemented.
Anshu defended her PhD in in December 2020. Her research profile and publication list is available here.
BCG vaccination policy in Guinea-Bissau
Cost and impact on mortality
Sanne M. Thysen, MD, PhD
In her thesis, Sanne assessed some of the consequences of the current BCG vaccination policy in Guinea-Bissau where a vial of BCG is only opened when a certain number of children are present at the health facility (restrictive vial-opening policy).
We found that this policy was associated with delays in BCG vaccination, and that only 38% of children received BCG within the first month of life. With monthly visits with BCG vaccination, we were able to increase the 1-month BCG coverage to 88%.
We asked mothers about their experience in seeking and not obtaining BCG vaccination, and found that the household costs of seeking BCG vaccination per child (USD 1.82) were equivalent to the UNICEF price range of a BCG vial.
We assessed the effect of early BCG vaccination on mortality in two cohorts. In one cohort, we assessed the effect of opening a vial of BCG for each child at monthly outreach villages and found no beneficial effect of BCG on neonatal mortality. While we found no effect on neonatal mortality, data from another cohort indicated that early BCG is important for survival from 1-35 months: neonatal BCG vaccination was associated with lower all-cause mortality among both TB-exposed and TB-unexposed children, supporting that timely BCG vaccination is important.
In light of the identified barriers, costs, and effects of early BCG vaccination, we estimated the impact of disregarding the restrictive vial-opening policy. Opening a vial of BCG for each child at the first contact with the health care system was estimated to reduce both TB mortality and all-cause mortality. The cost-effectiveness analyses showed that including the all-cause effects of BCG in the evaluation resulted in higher cost-effectiveness than merely including TB-specific effects.
The results from this thesis support that BCG should be provided timely. The restrictive vial-opening policy should be removed and all children ought to receive BCG at their first contact with the healthcare system. This would reduce both TB mortality and all-cause mortality, and would be highly cost-effective.
Sanne defended her PhD dissertation in April 2019. Her research profile and publication list are available here.