This is a preview. Log in through your library . Abstract Large cohort studies are often used to investigate the impact of genetic variants or other risk factors on the age at onset (AAO) of a chronic ...

BACKGROUND When analysing effects of maternal age on child outcomes, many researchers estimate sibling models to control for unobserved factors shared between siblings. Some have included birth year ...

This was a two-year research project (June 2003 - May 2005) under the ESRC Research Methods programme. The project involved the development of multilevel simultaneous equations models for the analysis ...

We will review and synthesise a wide array of statistical methods for analysing longitudinal data . While there are many excellent text books in this area, the presentation in these books can ...

A behind-the-scenes blog about research methods at Pew Research Center. For our latest findings, visit pewresearch.org. Identifying causal relationships from observational data is not easy. Still, ...