Bj Cowling

Breast cancer incidence and mortality in a transitioning Chinese population: current and future trends

Background:Projections of future trends in cancer incidence and mortality are important for public health planning.Methods:By using 1976–2010 data in Hong Kong, we fitted Poisson age-period-cohort models and made projections for future breast cancer incidence and mortality to 2025.Results:Age-standardised breast cancer incidence (/mortality) is projected to increase (/decline) from 56.7 (/9.3) in 2011–2015 to 62.5 (/8.6) per 100 000 women in 2021–2025.Conclusions:The incidence pattern may relate to Hong Kong’s socio-economic developmental history, while falling mortality trends are, most likely, due to improvements in survival from treatment advancement and improved health service delivery.

Interpreting Seroepidemiologic Studies of Influenza in a Context of Nonbracketing Sera.

Background: In influenza epidemiology, analysis of paired sera collected from people before and after influenza seasons has been used for decades to study the cumulative incidence of influenza virus infections in populations. However, interpretation becomes challenging when sera are collected after the start or before the end of an epidemic, and do not neatly bracket the epidemic. Methods: Serum samples were collected longitudinally in a community-based study. Most participants provided their first serum after the start of circulation of influenza A(H1N1)pdm09 virus in 2009. We developed a Bayesian hierarchical model to correct for nonbracketing sera and estimate the cumulative incidence of infection from the serological data and surveillance data in Hong Kong. Results: We analyzed 4,843 sera from 2,097 unvaccinated participants in the study, collected from April 2009 to December 2010. After accounting for nonbracketing, we estimated that the cumulative incidence of H1N1pdm09 virus infection was 45% (95% credible interval [CI] = 40%, 49%), 17% (95% CI = 13%, 20%), and 11% (95% CI = 6%, 18%) for children ages 0–18 years, adults 19–50 years, and older adults >50 years, respectively. Including all available data substantially increased precision compared with a simpler analysis based only on sera collected at 6-month intervals in a subset of participants. Conclusions: We developed a framework for the analysis of antibody titers that accounted for the timing of sera collection with respect to influenza activity and permitted robust estimation of the cumulative incidence of infection during an epidemic.

Birth weight and adult cardiovascular risk in a developing southern Chinese population: the Guangzhou Biobank Cohort Study

to deficient mothers show symptoms like irritability and failure-to-thrive. Furthermore, vitamin B12 has been reported to be successful in the treatment of sleep-wake rhythm disorders. This explorative study is the first to examine whether 1) maternal vitamin B12 and folate status during pregnancy are associated with excessive infant crying, and 2) whether this association is modified by the presence of psychosocial problems during pregnancy. Methods: From January 2003 till March 2004, all pregnant women in Amsterdam were approached during their first prenatal visit (613 weeks of gestation); 8266 women (response rate 67%) filled out a questionnaire covering sociodemographic data, lifestyle and (psychosocial) health; 4389 women also provided a blood sample for biomarker analyses. A few months (63) after delivery, 5132 women filled out a second questionnaire about the health of mother and infant. Vitamin B12 and folate concentrations were determined in serum, standardized for gestational age at blood sampling and then categorized into quintiles (Q1–Q5). Infant crying was measured by the question: ‘How many hours per day (24 hours) on average did your baby cry in the past week?’ Excessive crying was defined as crying > 3 hours per day on average in the past week. The following maternal psychosocial problems were measured by self-report: depressive symptoms, anxiety, pregnancy-related anxiety, jobstrain, and parenting stress. For this study, multiple births were excluded. Finally, complete data were available for respectively 2944 (vitamin B12 analyses) and 2644 (folate analyses) women. Appropriate institutional ethics committee clearance and participants’ informed consent were obtained. Results: The prevalence of excessive infant crying in our sample was 3.4%. Logistic regression analyses showed that vitamin B12 concentration was significantly associated with excessive crying, univariate as well as multivariate (adjusted for ethnicity, education, maternal age, parity and maternal smoking) (Q1:OR 5 3.59[1.58–8.16]; Q2:OR 5 2.63[1.12– 6.17]; Q3:OR 5 2.73[1.17–6.41]; Q4:OR 5 2.75[1.18–6.42]; Q5:reference group). Stratified analyses showed a much stronger association between vitamin B12 concentration and excessive crying among women who experienced one or more psychosocial problems during pregnancy compared to women who did not. Folate concentration was not significantly associated with excessive crying. Conclusions: This explorative study showed that maternal vitamin B12 status during early pregnancy is associated with excessive infant crying in the first months after birth. This association is modified by the presence of maternal psychosocial problems during pregnancy. Maternal folate status is not associated with excessive infant crying.