Eruptions are labelled by date of first sample collection in each case.
To test whether the properties of disease-associated alleles changed over time, disease-associated were binned into six-month intervals by date of first publication.
We charted the temporal distribution of influenza case-patients admitted to the University Hospital Heidelberg by date of first positive laboratory result, compared with influenza cases notified to the German national surveillance system by date of notification.
*Baseline diet factors are taken from participant's first post-MI food frequency questionnaire; Lifestyle factors are taken from corresponding questionnaire by date of first post-MI food frequency questionnaire.
Gestational age at delivery was determined by date of first day of the last menstrual period (LMP), or a gestational age estimate from an early ultrasound (≤ 25 weeks), the latter used when the two estimates disagreed by > 2 weeks.
In brief, the cohort includes 58 987 males employed for at least 180 days between 1946 and 1989, selected as a random sample stratified by date of first employment, place of work and area of mining.
Two groups were selected by date of first contact with the nephrologist: Group A, third quarter 1997, immediately before the start of the initiative, and Group B, third quarter 1999, six months after the last visit to a primary care provider had taken place.
For safety analyses, the length of exposure to the study drug was categorized by week (ie, 1 week = 1 to 7 days, 2 weeks = 8 to 14 days, etc) and was determined by the dates of first dispensing and last dose of the study drug.
Where possible, a resident without deep vein thrombosis or pulmonary embolism was matched to each patient by date of the first live birth after the patient's child.
Cases are listed by date of onset of first symptoms and corresponding CDC week, and parish or county of residence at the estimated time of infection.
