They analysed four years of computerised data on approximately two million visits provided by 206 practitioners in two departments, adult medicine and paediatrics, between 1997 and 2000.
However, the majority of the information on vital status was obtained from record linkage of computerised data on all deceased persons in the study period that were made available by 51 of the 74 municipalities in the CCCA region (covering more than 85% of the population).
Participating practices follow protocols for the recording and transferring of computerised data to the research database (Hollowell, 1997).
The practice had computerised data for all their patients dating back 20 years.
Computerised data extraction of information from free text has been used previously.
It is important to highlight that the CRUs and CROs use the same data collection and management tools, such as standardised list of child welfare indicators and unified computerised data management platform of DevInfo.
These patients were censored at the earliest date of the diagnosis of interest, first statin prescription, death, deregistration with the practice, last upload of computerised data, or date at end of study.
Observation time was calculated from the entry date to an exit date, which was defined as the earliest date of recorded fracture, date of death, date of deregistration with the practice, date of last upload of computerised data, or the study end date (30 June 2008).
17 For each patient we also determined an exit date, which was the earliest of date of recorded fracture, date of death, date of deregistration with the practice, date of last upload of computerised data, or the study end date (30 June 2008).
24 For each patient, we determined the right censor date, which was the earliest of the date of diagnosis of type 2 diabetes, date of death, date of deregistration with the practice, date of last upload of computerised data, or the study end date (31 March 2008).
