BACKGROUND Studies on long-term mortality after venous thromboembolism (VTE) are sparse. METHODS AND RESULTS Using Danish medical databases, we conducted a 30-year nationwide population-based cohort study of 128 223 patients with first-time VTE (1980-2011) and a comparison cohort of 640 760 people from the general population (without VTE) randomly matched by sex, year of birth, and calendar p...

OBJECTIVE There have been dramatic societal changes in East Asia over the last hundred years. Several of the established risk factors could have important period and cohort effects. This study explores temporal variation of dementia prevalence in mainland China, Hong Kong and Taiwan taking study methods into account. METHODS Seventy prevalence studies of dementia in mainland China, Hong Kong ...

OBJECTIVE The aim of this study was to evaluate the influence on preterm delivery of changes in putative genetic and environmental risk factors between two consecutive births. Low social status is a suspected risk indicator of preterm delivery, but the impact of social mobility has not been studied before. PARTICIPANTS The study uses national cohorts in which women act as their own controls. ...

Since the mid-1980s, cesarean section rates in Canada have declined. By 1993, 18 of every 100 deliveries were by cesarean section, compared with close to 20 per 100 in 1987. As well, in 1993, 9 of every 100 deliveries were primary cesareans, down from a high of almost 11 per 100 in the mid-1980s. And the repeat cesarean section rate fell from 39 per 100 cesareans in the mid-1980s to 34 in 1993....

The timing of marriages, first birth interval and the prevalence of premarital conception (PMC) among women of successive birth cohorts in one rural county in Yunnan, China, were examined. Detailed pregnancy histories were collected for 1,336 women aged 15-64 years using a Life History Calendar. The rising marriage age and shorter first birth interval correspond to over-all changes in the Chine...

OBJECTIVE We have investigated age-period-cohort effects and spatial and temporal trends for the incidence of type 1 diabetes among 0- to 14-year-old children in Norway. RESEARCH DESIGN AND METHODS We included children with the diagnosis of type 1 diabetes in Norway during 1973-1982 and 1989-2003. We studied age, calendar period, and birth cohort effects using Poisson regression, including Ho...

the relation between periconceptional vaginal permicide use and sex ratio at birth, birth weight, and the frequency of congenital anomalies was examined in a cohort of 2,712 new york city obstetric patients, 149 of whom (5.5 per cent) became pregnant while using spermicides or had used spermicides before and after conception. periconceptional spermicide use was not associated with any important...

INTRODUCTION Difficulties with visual perception (VP) are often described in children with neurological or developmental problems. However, there are few data regarding the range of visual perceptual abilities in populations of normal children, or on the impact of these abilities on children's day-to-day functioning. METHODS Data were obtained for 4512 participants in an ongoing birth cohort ...