BACKGROUND Electronic administrative data exist in several domains which, if linked, are potentially useful for research. However, benefits from data linkage should be considered alongside risks such as the threat to privacy. Avon Longitudinal Study of Parents and Children (ALSPAC) is a birth cohort study. The Project to Enhance ALSPAC through Record Linkage (PEARL) was established to enrich th...

BACKGROUND AND OBJECTIVES We hypothesized that longitudinal changes in uric acid (UA) may have independent associations with changes in nutritional parameters over time and consequently, long-term survival of patients on maintenance hemodialysis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We conducted a retrospective, longitudinal cohort study of a clinical database containing the medical ...

OBJECTIVE Despite recent research demonstrating associations between violence and depression in adults, links in adolescents are uncertain. This study aims to assess the longitudinal associations between young people's depression and later violent outcomes. METHOD We used data from three cohorts with different measurements of depression exposures and subsequent violent outcomes. In a Dutch co...

conclusions the levels of hemoglobin can be used to predict preeclampsia and monitoring the pregnant women and its regular measure in 3 trimesters help us to identify women at risk for preeclampsia. background preeclampsia is one of the most serious complications during pregnancy with important effects on health of mother and fetus that causes maternal and fetal morbidity and mortality. this st...

Longitudinal studies are often used to investigate age-related developmental change. Whereas a single cohort design takes a group of individuals at the same initial age and follows them over time, an accelerated longitudinal design takes multiple single cohorts, each one starting at a different age. The main advantage of an accelerated longitudinal design is its ability to span the age range of...

BACKGROUND The common cause account suggests that there is a third factor causing aging effects in both sensory and cognitive functioning, hypothesized to be the integrity of the central nervous system [Lindenberger and Baltes; Psychol Aging 1994;9:339-355]. Importantly, the common cause account was developed based on cross-sectional data, which are especially biased by cohort effects. However,...

Serious instability occurred only with ergometrine injection. This result is in line with two earlier longitudinal studies during transport to and within tropical countries, in which only ergometrine injection, methylergometrine injection, and retinol capsules showed a loss of active ingredient; 12 other essential drugs were stable. 5 As all three studies focused on essential drugs suspected of...

BACKGROUND AND OBJECTIVES: Environmental factors such as serious trauma or abuse and related stress can lead to nightmares or night terrors. Being bullied can be very distressing for children, and victims display long-term social, psychological, and health consequences. Unknown is whether being bullied by peers may increase the risk for experiencing parasomnias such as nightmares, night terrors...

are closed populations defined and bounded by their timepoints of entry, often but not necessarily at birth. In this issue, a classic article by Kermack, McKendrick and McKinley reprinted from the Lancet of 1934 illustrates an early use of cohort analysis. Such analyses follow successive generations of entrants through the life course. The object is to link the pattern of specified outcomes to ...