Sentence examples for dates were ascertained from inspiring English sources
The history of having had a sigmoidoscopy and the frequency of physician visits during the 5-year period prior to index dates were ascertained for all cases and controls, using records of the medical services database.
Race, gender, age and ESRD treatment start date were ascertained from patient report and the USRDS Medical Evidence Standard Analysis Files.
Dates of all deaths within 28 days following an upper gastrointestinal bleed admission date or primary care event date were ascertained using the linkage between the GPRD primary care practices and the UK Office for National Statistics death register.
In case of death or emigration, the respective date was ascertained.
Self-reported healthcare contacts were matched with contacts extracted from the medical records and subsequently the exact date was ascertained.
Influenza vaccination status (including vaccination date) was ascertained from an online immunization registry that is linked to clinical and non-clinical vaccination records from the region.
Use of aspirin, selective cyclooxygenase-2 (sCOX-2) inhibitors, and other non-steroidal anti-inflammatory drugs (NSAIDs) from 1995 through 2008 (⩾1 year before the index date) was ascertained via the Danish National Prescription Database.
In each follow-up survey from the third, whether a caregiver reported that the child had a dental visit due to dental caries in the 12 months before the survey date was ascertained (eg, between 18 and 30 months at the third survey and between 30 and 42 months at the fourth survey).
Causes and dates of deaths were ascertained using record linkages with central cancer registries, death indexes or by follow-up mailings and subsequent enquiries to municipality registries, regional health departments, physicians or hospitals.
Dates of death were ascertained through record linkage to Social Security Administration mortality files.
Dates of death were ascertained by linkage to the Social Security Administration mortality files.
