Quality of vital event data for infant mortality estimation in prospective, population-based studies: an analysis of secondary data from Asia, Africa, and Latin America.

INTRODUCTION: Infant and neonatal mortality estimates are typically derived from retrospective birth histories collected through surveys in countries with unreliable civil registration and vital statistics systems. Yet such data are subject to biases, including under-reporting of deaths and age misreporting, which impact mortality estimates. Prospective population-based cohort studies are an underutilized data source for mortality estimation that may offer strengths that avoid biases. METHODS: We conducted a secondary analysis of data from the Child Health Epidemiology Reference Group, including 11 population-based pregnancy or birth cohort studies, to evaluate the appropriateness of vital event data for mortality estimation. Analyses were descriptive, summarizing study designs, populations, protocols, and internal checks to assess their impact on data quality. We calculated infant and neonatal morality rates and compared patterns with Demographic and Health Survey (DHS) data. RESULTS: Studies yielded 71,760 pregnant women and 85,095 live births. Specific field protocols, especially pregnancy enrollment, limited exclusion criteria, and frequent follow-up visits after delivery, led to higher birth outcome ascertainment and fewer missing deaths. Most studies had low follow-up loss in pregnancy and the first month with little evidence of date heaping. Among studies in Asia and Latin America, neonatal mortality rates (NMR) were similar to DHS, while several studies in Sub-Saharan Africa had lower NMRs than DHS. Infant mortality varied by study and region between sources. CONCLUSIONS: Prospective, population-based cohort studies following rigorous protocols can yield high-quality vital event data to improve characterization of detailed mortality patterns of infants in low- and middle-income countries, especially in the early neonatal period where mortality risk is highest and changes rapidly.

Functional limitation trajectories and their determinants among women in the Philippines.

BACKGROUND: Limited evidence exists regarding how functional limitation patterns of women in developing countries unfold through midlife and into old age, a critical period during which the tendency to develop severe problems is fomented. OBJECTIVE: Functional limitation prevalence and patterns through midlife into early old age, and their determinants, are examined among women in the Philippines. METHODS: Data from the Cebu Longitudinal Health and Nutrition Study are monitored from 1994 to 2015. Patterns are categorized using group-based trajectory modeling. Predictors of group membership are modeled. RESULTS: About half responding to all survey waves report functional limitation at least once over the study period. Movements in and out of functional limitation states are common. Between age 30 and 70, trajectories are categorized into four groups: 1) robust, 2) late onset, 3) early onset, and 4) recovery. Being married, living in a nuclear household, higher successful birth ratio, and higher education associate with favorable trajectories. More births, higher age at first birth, wealth, and urbanicity associate with less favorable trajectories. CONCLUSION: Many possible routes into and out of functional limitation exist. The manifold patterns can be grouped into common trajectories. A number of earlier life characteristics associate with these trajectories. CONTRIBUTION: This is the first analysis to ascertain common functional limitation trajectories and earlier life predictors among women as they age in a high fertility developing country setting. Recognizing these is an important step toward understanding global health given aging of the population and the likelihood of functional problems developing in women as they move into old age.

C-reactive protein response to influenza vaccination as a model of mild inflammatory stimulation in the Philippines.

BACKGROUND: C-reactive protein (CRP) is increasingly measured as a marker of systemic inflammation that predicts elevated risk for cardiovascular disease. Influenza vaccination is a mild pro-inflammatory stimulus, and the CRP response to vaccination may provide additional information on individual differences in inflammatory response and risk for disease. AIM: To document the pattern of CRP response to influenza vaccination among a large sample of older women in the Philippines. The Philippines exemplifies current global trends toward increasing rates of overweight/obesity, but also maintains relatively high rates of infectious disease. The secondary aim of the study is to investigate the impact of infectious symptoms on the pattern of response to vaccination. METHODS: A community-based sample of 934 women (mean age=55.4 years) received the influenza vaccine. CRP was assessed at baseline and 72h post-vaccination. Descriptive, non-parametric, and parametric analyses were implemented to assess the magnitude of CRP response, and to investigate whether responses were associated with baseline CRP or the presence of infectious symptoms prior to vaccination. RESULTS: Influenza vaccination resulted in a statistically significant CRP response of 0.35mg/L (p<0.001), representing a 30.2% increase from baseline. For individuals with symptoms of infectious disease at baseline, the CRP response was smaller (12.9%) and not statistically significant (p=0.77). Lower CRP at baseline was associated with larger CRP response to vaccination in the entire sample, and among participants without recent symptoms of infection. CONCLUSIONS: Influenza vaccination produces a mild CRP response in the Philippines. This study extends prior research in US and European populations validating influenza vaccination as an in vivo model for investigating the dynamics of inflammation, but also raises potential complications in settings where rates of infectious disease are elevated.