Research

Works Published


Health costs of reproduction are minimal despite high fertility, mortality and subsistence lifestyle
Abstract
Women exhibit greater morbidity than men despite higher life expectancy. An evolutionary life history framework predicts that energy invested in reproduction trades-off against investments in maintenance and survival. Direct costs of reproduction may therefore contribute to higher morbidity, especially for women given their greater direct energetic contributions to reproduction. We explore multiple indicators of somatic condition among Tsimane forager-horticulturalist women (Total Fertility Rate = 9.1; n =  592 aged 15–44 years, n = 277 aged 45+). We test whether cumulative live births and the pace of reproduction are associated with nutritional status and immune function using longitudinal data spanning 10 years. Higher parity and faster reproductive pace are associated with lower nutritional status (indicated by weight, body mass index, body fat) in a cross-section, but longitudinal analyses show improvements in women’s nutritional status with age. Biomarkers of immune function and anemia vary little with parity or pace of reproduction. Our findings demonstrate that even under energy-limited and infectious conditions, women are buffered from the potential depleting effects of rapid reproduction and compound offspring dependency characteristic of human life histories.

Gurven, M., Costa, M., Trumble, B., Stieglitz, J., Beheim, B., Rodriguez, D. E., Hooper P. L., & Kaplan, H. (2016.) Health costs of reproduction are minimal despite high fertility, mortality and subsistence lifestyle, Scientific Reports, 6. doi:10.1028/srep30056


Neonatal, postneonatal, childhood, and under-5 mortality for 187 countries, 1970–2010: a systematic analysis of progress towards Millennium Development Goal 4
Summary
Background
Previous assessments have highlighted that less than a quarter of countries are on track to achieve Millennium Development Goal 4 (MDG 4), which calls for a two-thirds reduction in mortality in children younger than 5 years between 1990 and 2015. In view of policy initiatives and investments made since 2000, it is important to see if there is acceleration towards the MDG 4 target. We assessed levels and trends in child mortality for 187 countries from 1970 to 2010.
Methods
We compiled a database of 16 174 measurements of mortality in children younger than 5 years for 187 countries from 1970 to 2009, by use of data from all available sources, including vital registration systems, summary birth histories in censuses and surveys, and complete birth histories. We used Gaussian process regression to generate estimates of the probability of death between birth and age 5 years. This is the first study that uses Gaussian process regression to estimate child mortality, and this technique has better out-of-sample predictive validity than do previous methods and captures uncertainty caused by sampling and non-sampling error across data types. Neonatal, postneonatal, and childhood mortality was estimated from mortality in children younger than 5 years by use of the 1760 measurements from vital registration systems and complete birth histories that contained specific information about neonatal and postneonatal mortality.
Findings
Worldwide mortality in children younger than 5 years has dropped from 11·9 million deaths in 1990 to 7·7 million deaths in 2010, consisting of 3·1 million neonatal deaths, 2·3 million postneonatal deaths, and 2·3 million childhood deaths (deaths in children aged 1–4 years). 33·0% of deaths in children younger than 5 years occur in south Asia and 49·6% occur in sub-Saharan Africa, with less than 1% of deaths occurring in high-income countries. Across 21 regions of the world, rates of neonatal, postneonatal, and childhood mortality are declining. The global decline from 1990 to 2010 is 2·1% per year for neonatal mortality, 2·3% for postneonatal mortality, and 2·2% for childhood mortality. In 13 regions of the world, including all regions in sub-Saharan Africa, there is evidence of accelerating declines from 2000 to 2010 compared with 1990 to 2000. Within sub-Saharan Africa, rates of decline have increased by more than 1% in Angola, Botswana, Cameroon, Congo, Democratic Republic of the Congo, Kenya, Lesotho, Liberia, Rwanda, Senegal, Sierra Leone, Swaziland, and The Gambia.
Interpretation
Robust measurement of mortality in children younger than 5 years shows that accelerating declines are occurring in several low-income countries. These positive developments deserve attention and might need enhanced policy attention and resources.

Rajaratnam, J. K., Marcus, J. R., Flaxman, A. D., Wang, H., Levin-Rector, A., Dwyer, L., Costa, M., Lopez, A. D., & Murray, C. J. (2010). Neonatal, postneonatal, childhood, and under-5 mortality for 187 countries, 1970–2010: a systematic analysis of progress towards Millennium Development Goal 4. The Lancet, 375(9730), 1988-2008. doi:10.1016/S0140-6736(10)60703-9


Worldwide mortality in men and women aged 15–59 years from 1970 to 2010: a systematic analysis
Summary
Background
Adult deaths are a crucial priority for global health. Causes of adult death are important components of Millennium Development Goals 5 and 6. However, adult mortality has received little policy attention, resources, or monitoring efforts. This study aimed to estimate worldwide mortality in men and women aged 15–59 years.
Methods
We compiled a database of 3889 measurements of adult mortality for 187 countries from 1970 to 2010 using vital registration data and census and survey data for deaths in the household corrected for completeness, and sibling history data from surveys corrected for survival bias. We used Gaussian process regression to generate yearly estimates of the probability of death between the ages of 15 years and 60 years (45q15) for men and women for every country with uncertainty intervals that indicate sampling and non-sampling error. We showed that these analytical methods have good predictive validity for countries with missing data.
Findings
Adult mortality varied substantially across countries and over time. In 2010, the countries with the lowest risk of mortality for men and women are Iceland and Cyprus, respectively. In Iceland, male 45q15 is 65 (uncertainty interval 61–69) per 1000; in Cyprus, female 45q15 is 38 (36–41) per 1000. Highest risk of mortality in 2010 is seen in Swaziland for men (45q15 of 765 [692–845] per 1000) and Zambia for women (606 [518–708] per 1000). Between 1970 and 2010, substantial increases in adult mortality occurred in sub-Saharan Africa because of the HIV epidemic and in countries in or related to the former Soviet Union. Other regional trends were also seen, such as stagnation in the decline of adult mortality for large countries in southeast Asia and a striking decline in female mortality in south Asia.
Interpretation
The prevention of premature adult death is just as important for global health policy as the improvement of child survival. Routine monitoring of adult mortality should be given much greater emphasis.

Rajaratnam, J. K., Marcus, J. R., Levin-Rector, A., Chalupka, A. N., Wang, H., Dwyer, L., Costa, M., Lopez, A.D., & Murray, C. J. (2010). Worldwide mortality in men and women aged 15–59 years from 1970 to 2010: a systematic analysis. The Lancet, 375(9727), 1704-1720. doi:10.1016/S0140-6736(10)60517-X

Reports

Building Momentum: Global Progress Toward Reducing Maternal and Child Mortality. Seattle, WA: IHME, 2010. Contributing Author.