Follow-up extended from the date of first-time ICU admission until death or migration or until 3 years after ICU admission, whichever came first.
Follow up began on the date of first-time ICU admission and continued until death, migration, 365 days after ICU admission or 31 December 2008, whichever came first.
16 For each patient included, we queried medical histories on comorbidity from the DNRP, and computed CCI scores 17 based on all comorbidity diagnoses registered within 10 years preceding the date of first-time PC diagnosis (ie, index date).
We also calculated the HR for diabetic subjects whose dates of first-time ambulatory visit for diabetes were in 1997 or earlier, 1998 1999, or 2000 and observed an adjusted HR of 1.72 (1.38–1.77), 1.38 (1.32–1.44), and 1.25 (1.18–1.33), respectively.
For each patient who received a GON injection, information on age (measured as a continuous variable), gender, headache diagnosis, date of first visit, time from first visit to injection, site of injection, past and current medication, effects of injection and eventual follow-up treatment was collected using a standardized pro forma.
Nestboxes were checked regularly to obtain data on date of first egg, hatching time and breeding success throughout the breeding season.
Within the study population we identified at random up to four control patients per breast cancer case patient, matched to case patients on age (same year of birth), sex, general practice, and index date (i.e., the control patient got the same index date assigned, i.e., the date of the first-time recorded cancer diagnosis of the case patient).
The clinical end point of this study was cause-specific mortality, and the time of its occurrence was computed from the date of first diagnosis to the time of death or censored at the date of the last recorded follow-up for living patients or for those who died from liposarcoma-unrelated conditions.
