Knowledge regarding the heterogeneity of BMI trajectories is limited for the Canadian population. Using latent class growth modelling, four distinct BMI trajectories of individuals from young adulthood to middle age were identified for both women and men from the longitudinal data of the National Population Health Survey. The associations between BMI trajectories and the individuals’ sociodemographic characteristics and behavioural factors were also examined. Aboriginal women were found more likely to be in the long-term overweight or obese groups. It reveals that increased years of smoking, drinking, and being physically active were associated with lowering the BMI trajectory in all groups for both women and men, with some exceptions in the long-term normal weight group for men. Increased years of rural living, being employed, and living with low income were associated with raising the BMI trajectory in all groups for women and in some groups for men. Food insecurity was associated with raising the BMI trajectory in each group for both women and men.

Meng Wang

Yanqing Yi

Barbara Roebothan

Jennifer Colbourne

Victor Maddalena

Peizhong Peter Wang

Guang Sun

Trajectories of Body Mass Index from Young Adulthood to Middle Age among Canadian Men and Women

<i>Aim</i>. To identify sociodemographic and medical characteristics associated with preterm birth survival.<i> Methods</i>. A retrospective study of singleton births was performed using Missouri linked data for the years 1978 to 2005. We computed hazard ratios (HR) and 95&#x25; confidence intervals (CI) using Cox proportional hazards model.<i> Results</i>. High rates of infant, neonatal, and postneonatal mortality were observed among preterm as compared to term births. White are at low risk for postneonatal (HR = 0.77, CI: 0.65, 0.90) and infant mortality (HR = 0.90, CI: 0.81, 0.99) compared to blacks. We observed increased risks of all mortality types for preterm deliveries by caesarean section (neonatal HR = 1.53, CI: 1.40, 1.68; postneonatal HR = 1.39, CI: 1.22, 1.58; infant HR = 1.37, CI: 1.27, 1.48). As compared to nonsmokers, preterm singletons born to smoking mothers are 69&#x25; more likely to experience postneonatal mortality and have a 17&#x25; increased risk for infant death.<i> Conclusions</i>. Caesarean section is associated with increased risk of all types of mortality. Racial disparity is still a concern. Further research is required to identify the detailed differences in structure and procedures that result in the disadvantage associated with preterm birth especially with respect to caesarean section and race.

Boubakari Ibrahimou

Sireesha Kodali

Hamisu Salihu

Survival of Preterm Singleton Deliveries: A Population-Based Retrospective Study

<i>Purpose.</i> To examine the association between previous preterm birth and the risk of stillbirth.<i> Methods.</i> This population-based retrospective cohort study analyzed live births and stillbirth records in Missouri (1989&#x2013;1997). The main outcome of interest was stillbirth occurrence while the exposures were prior preterm birth. Adjusted odds ratios and 95&#x25; confidence intervals were computed using logistic regression.<i> Results.</i> Women who had a previous preterm birth have 63&#x25; increased odds of stillbirth in singleton pregnancies and 75&#x25; increased odds in twins as compared to those who did not have a preterm birth in a prior pregnancy (AOR = 1.63, 95&#x25; CI = 1.41&#x2013;1.88 and AOR = 1.75, 95&#x25; CI = 1.20&#x2013;2.56), respectively. The most significant risk factor for stillbirth in singleton pregnancies was uterine bleeding (AOR = 5.89, 95&#x25; CI = 5.13&#x2013;6.76). In twin pregnancies, it was the condition hydramnios/oligohydramnios (AOR = 4.72, 95&#x25; CI = 3.70&#x2013;6.02). Eclampsia was associated with a heightened risk of stillbirth in singletons (AOR = 2.45, 95&#x25; CI = 1.41&#x2013;4.12), but not in twins (AOR = 0.96, 95&#x25; CI = 0.13&#x2013;7.00). Black mothers were more likely than white to experience stillbirth (AOR = 2.10, 95&#x25; CI = 1.99&#x2013;2.22 for singletons and AOR = 1.51, 95&#x25; CI = 1.27&#x2013;1.79 for twins).<i> Conclusion.</i> Stillbirth is a vital public health issue and its etiology is not well understood. Previous history of preterm birth was found to be associated with future stillbirth. Targeted early medical and obstetric care and interventions among women with preterm birth history may potentially reduce the likelihood of stillbirth.

Cynthia Anozie

Cara de la Cruz

Previous Preterm Birth and Current Maternal Complications as a Risk Factor of Subsequent Stillbirth

Recently published analyses for four smoking-related diseases show that the declining excess relative risk by time quit is well fitted by the negative exponential model. These analyses estimated the half-life of this excess, that is, the time after quitting when the excess relative risk reaches half that for continuing smokers. We describe extensions of the simple model. One quantifies the decline following an exposure reduction. We show that this extension satisfactorily predicts results from studies investigating the effect of reducing cigarette consumption. It may also be relevant to exposure reductions following product-switching. Another extension predicts changes in excess relative risk occurring following multiple exposure changes over time. Suitable published epidemiological data are unavailable to test this, and we recommend its validity to be investigated using large studies with data recorded on smoking habits at multiple time points in life. The basic formulae described assume that the excess relative risk for a continuing smoker is linearly related to exposure and that the half-life is invariant of age. We describe model adaptations to allow for nonlinear dose-response and for age-dependence of the half-life. The negative exponential model, though relatively simple, appears to have many potential uses in epidemiological research for summarizing variations in risk with exposure changes.

Peter N. Lee

John Hamling

John Fry

Barbara Forey

Using the Negative Exponential Model to Describe Changes in Risk of Smoking-Related Diseases following Changes in Exposure to Tobacco

<i>Background</i>. The sudden out-of-hospital cardiac death (SOHCD) in Russia is poorly investigated. The aim of study was to determine structure of SOHCD in Moscow. <i>Methods</i>. SOHCD were analyzed according to data for 2005&#x2013;2009 from the 2nd Thanatology Department of Forensic Medicine of Moscow that serves 2502836 citizens in Moscow. <i>Results</i>. Prevalence of SOHCD was 49.1&#x25; of autopsies for all age groups and in 8.9&#x25; in the group aged 1&#x2013;45 (22.3 cases per 100000 population/year). The frequency of SOHCD progressively increased with age. Most SOHCD victims (82&#x25;) were males. The diagnosis of cardiomyopathy was prevalent (80&#x2013;96&#x25;) in the age 1&#x2013;45 group; in 11&#x2013;15 more 30&#x25; had normal heart; after 35 years of age, the role of ischaemic heart disease increased. In 67&#x25; of the people aged 19&#x2013;25 SOHCD was associated with traces of alcohol (0.3&#x2013;3.0 promile). <i>Conclusion</i>. The proportion of SOHCD in the Moscow population over all age groups has reached 123.2 per 100000 citizens annually. In the age group 1&#x2013;45, the prevalence of SOHCD was 22.3 cases per 100000 citizens per year. The risk of SOHCD was greater in males. Possibly the role of alcohol in SOHCD in people older than 20 increased.

Leonid Makarov

Vera Komoliatova

Natalia Fedina

Yuri Solokhin

Prevalence of Out-of-Hospital Sudden Cardiac Death in Moscow in 2005&#x2013;2009

Despite alarming statistics on cystic echinococcosis (CE) in humans and the importance of dog and ruminant populations, no epidemiological investigations have been performed on CE in Sidi Kacem Province (North-West of Morocco). A part of large research project was devoted to determine the status of CE in ruminants. This paper reports the results of the investigations carried out in the 10 abattoirs of this region, over four successive years (April 2009&#x2013;March 2013). A total of 1,302 sheep, 652 head of cattle, and 136 goats were postmortem examined and hydatid cysts were collected and examined. The overall CE prevalence of infection was 42.9&#x25; in cattle, 11.0&#x25; in sheep, and 1.5&#x25; in goats. The prevalence shows significant association with age in sheep and cattle; sheep above 3 years and cattle above 5 years are highly infected (64.0&#x25; and 72.2&#x25;, resp.). Only liver and lungs are found to be infected. Molecular analyses identified G1, G2, and G3 of <i>E. granulosus</i> sensu stricto in liver and lung samples. Cyst fertility was significantly higher in sheep (54.9&#x25;) than in cattle (50.3&#x25;). These findings suggest that control measures should target not only sheep but also cattle.

Ikhlass El Berbri

Anne Fran&#xe7;oise Petavy

Gerald Umhang

Mohammed Bouslikhane

Ouafaa Fassi Fihri

Franck Bou&#xe9;

Allal Dakkak

Epidemiological Investigations on Cystic Echinococcosis in North-West (Sidi Kacem Province) Morocco: Infection in Ruminants

This epidemiological study was designed to evaluate the prevalence of undetected hypertension in an apparently healthy western Indian population having no history of major illness. 3629 individuals of <svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-1.16493pt" id="M1" height="9.26535pt" version="1.1" viewBox="-0.0498162 -8.10042 8.08224 9.26535" width="8.08224pt"><g transform="matrix(.0135,0,0,-0.0135,0,0)"><path id="g117-94" d="M531 285V335L57 550V494L473 310L57 127V71L531 285ZM531 -40V10H57V-40H531Z"/></g></svg>18 years of age were included in the study. Hypertension (HTN) was defined as systolic blood pressure (SBP) <svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-1.16493pt" id="M2" height="9.26535pt" version="1.1" viewBox="-0.0498162 -8.10042 8.08224 9.26535" width="8.08224pt"><g transform="matrix(.0135,0,0,-0.0135,0,0)"><use xlink:href="#g117-94"/></g></svg> 140&#x2009;mmHg or diastolic blood pressure (DBP) &#x2265; 90&#x2009;mmHg and prehypertension (PHTN) as SBP &#x2265; 120&#x2013;139&#x2009;mmHg or DBP &#x2265; 80&#x2013;89&#x2009;mmHg, but without HTN. The prevalence of undiagnosed HTN in the total population was 26&#x25; and was 11&#x25; and 40&#x25; in the young (<svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-1.16493pt" id="M3" height="9.26535pt" version="1.1" viewBox="-0.0498162 -8.10042 8.08224 9.26535" width="8.08224pt"><g transform="matrix(.0135,0,0,-0.0135,0,0)"><path id="g117-93" d="M531 71V127L115 310L531 494V550L57 335V285L531 71ZM531 -40V10H57V-40H531Z"/></g></svg>40-year) and old (<svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-0.6617599pt" id="M4" height="8.21822pt" version="1.1" viewBox="-0.0498162 -7.55646 8.08224 8.21822" width="8.08224pt"><g transform="matrix(.0135,0,0,-0.0135,0,0)"><path id="g117-92" d="M512 230V281L75 514V456L453 256V254L75 55V-3L512 230Z"/></g></svg>40-year) populations, respectively. The prevalence of PHTN, 40&#x25; in the overall population, was nearly the same in the young (39&#x25;) and the old population (42&#x25;). The risk factor most strongly associated with PHTN and HTN was obesity, showing the highest odds ratio in the overall (PHTN 2.14; 95&#x25; CI 1.20&#x2013;3.81; HTN 2.72; 95&#x25; CI 1.53&#x2013;4.85), the young (PHTN 2.29; 95&#x25; CI 1.25&#x2013;4.21; HTN 2.92; 95&#x25; CI 1.59&#x2013;5.35), and the old (PHTN 1.13; 95&#x25; CI 0.65&#x2013;1.96; HTN 1.38; 95&#x25; CI 0.79&#x2013;2.4) populations. Hypertension is a major risk factor for cardiovascular diseases which must not be ignored, especially in the western Indian population.

Anand N. Shukla

Tarun Madan

Bhavesh M. Thakkar

Meena M. Parmar

Komal H. Shah

Prevalence and Predictors of Undiagnosed Hypertension in an Apparently Healthy Western Indian Population

Incidence and mortality rates are considered as a guideline for planning public health strategies and allocating resources. We apply functional data analysis techniques to model age-specific brain cancer mortality trend and forecast entire age-specific functions using exponential smoothing state-space models. The age-specific mortality curves are decomposed using principal component analysis and fit functional time series model with basis functions. Nonparametric smoothing methods are used to mitigate the existing randomness in the observed data. We use functional time series model on age-specific brain cancer mortality rates and forecast mortality curves with prediction intervals using exponential smoothing state-space model. We also present a disparity of brain cancer mortality rates among the age groups together with the rate of change of mortality rates. The data were obtained from the Surveillance, Epidemiology and End Results (SEER) program of the United States. The brain cancer mortality rates, classified under International Classification Disease code ICD-O-3, were extracted from SEER<svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-0.04981041pt" id="M1" height="6.25997pt" version="1.1" viewBox="-0.0498162 -6.21016 8.08224 6.25997" width="8.08224pt"><g transform="matrix(.0135,0,0,-0.0135,0,0)"><path id="g113-43" d="M471 153C471 170 463 194 452 212C400 220 373 229 322 255C373 281 400 290 452 298C463 316 471 339 471 357C456 366 431 371 410 370C377 329 356 310 308 279C311 336 317 364 336 413C326 432 310 451 294 459C279 451 262 432 252 413C271 364 277 336 280 279C232 310 211 329 178 370C157 371 132 367 117 357C117 340 125 316 136 298C188 290 215 281 266 255C215 229 188 220 136 212C125 194 117 171 117 153C132 144 157 139 178 140C211 181 232 200 280 231C277 174 271 146 252 97C262 78 278 59 294 51C309 59 326 78 336 97C317 146 311 174 308 231C356 200 377 181 410 140C431 139 456 143 471 153Z"/></g></svg>Stat software.

Keshav P. Pokhrel

Chris P. Tsokos

Forecasting Age-Specific Brain Cancer Mortality Rates Using Functional Data Analysis Models

Cox model has been the commonly used method in past analyses of association between obesity and the risk estimates of cancer in situations where the subjects have also died (or could die) of noncancer events (competing events). The Cox model does not address the presence of competing events convincingly. The competing risk approach accommodates the fact that individuals who died of other causes (competing events) will never die of cancer and thus provides more realistic estimates. This study uses the competing risk approach to study the association of obesity and cancer mortality and compare the analysis results with those based on the traditional Cox model. It was seen that while the cause-specific hazard rate of cancer is significantly higher for obese population compared to normal weight population, the difference is not significant using competing risk approach. We demonstrated that higher cause-specific hazard rate does not necessarily imply higher incidence rate and in situations involving competing events we recommend using competing risk approach in addition to the Cox regression model.

Milan Bimali

Jianghua He

Association between Obesity and Cancer: An Analysis Using the Competing Risk Regression Approach

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Advances in Epidemiology