A frequently used study design within epidemiology is large cohort studies. In some situations additional information which is not included in the cohort, for instance biological material stored in biobanks, is required. The availability of such material is usually limited and might be very expensive to analyze for the entire cohort. A reasonable strategy is therefore to restrict the study samp...

Researchers investigated whether antipsychotic drugs were associated with venous thromboembolism. A population based nested case-control study design was used. Data were taken from the UK QResearch primary care database consisting of 7 267 673 patients. Cases were adult patients with a first ever record of venous thromboembolism between 1 January 1996 and 1 July 2007. For each case, up to four ...

Nested case-control designs (or equivalently, incidence density sampling designs) are are a common approach for reducing the costs the costs of exposure assessment in a prospective epidemiologic study. Exposure data are obtained from all cases and a pre-specified number of controls randomly chosen at each failure time from all subjects who had entered the study but had not failed or left it yet...

This paper presents a test-case generator for SQL queries. Starting with a set of related SQL views that can include existential subqueries in the conditions, the technique finds a database instance that can be used as a test-case for the target view. The proposal reduces the problem of generating the test-cases to a Constraint Satisfaction Problem using finite domain constraints. In particular...

OBJECTIVE Although numerous studies have found higher rates of abortion and still births following consanguinity (familial marriages), the question of whether consanguinity significantly increases the risk of neonatal death has inadequately been addressed.This study aims to evaluate familial marriage effects on neonatal death in rural areas in Iran. MATERIALS AND METHODS In this nested case-c...

Abstract The nested distance builds on the Wasserstein to quantify difference of stochastic processes, including also evolution information modelled by filtrations. Sinkhorn divergence is a relaxation distance, which can be computed considerably faster. For this reason we employ and take advantage related (fixed point) iteration algorithm. Furthermore, investigate transition entropy throughout ...

BACKGROUND The nested case-control design can be a very efficient approach to an epidemiological investigation. In order to obtain unbiased estimates of relative risk, controls should be selected by incidence density sampling, which involves matching each case to a sample of those who are at risk at the time of case occurrence. METHODS This paper presents a simple computer program for inciden...

Andersen et al. (1985, Biometrics 41, 921-932) gave an estimator of the cumulative relative mortality comparing rates of death in an epidemiologic cohort to an external population as a function of time when covariate information is available on all cohort members. We present an analogous estimator when covariate information is known only on a nested case-control sample. Counting process techniq...

Nested case-control (NCC) design is a popular sampling method in large epidemiological studies for its cost effectiveness to investigate the temporal relationship of diseases with environmental exposures or biological precursors. Thomas' maximum partial likelihood estimator is commonly used to estimate the regression parameters in Cox's model for NCC data. In this article, we consider a situati...

OBJECTIVES To determine the incidence of neonatal dehydration leading to rehospitalization, whether clinical and health services data could predict its occurrence, and the outcome of dehydrated infants. METHODS We employed a retrospective case-control design nested within a cohort of 51 383 newborns weighing 2000 g or more, with a gestational age of 36 weeks or more born at 11 Kaiser Permanen...