Date coverage varies greatly by country, see the data availability for date coverage http://esa.un.org/MigFlows/Data%20availability.html.html
By including a control variable for number of months of data availability following the index date, we annualize costs through a post-estimation prediction under the assumption that all subjects are followed for 12 months.
We used data from the counties' computerized prescription registries during three time periods, corresponding to the dates of data availability in the counties; 1991 2007 (North Jutland County), 1996 2007 (Aarhus County), and 1998 2007 (Ringkjøbing and Viborg Counties).
ICD-O codes 9700/3, 9709/3, 9701/3 and ICD-10 codes C84.0, C84.8, C84.8 were used to identify cases of CTCL diagnosed statewide from 1996 to 2010 (dates of data availability).
Both cases and controls are limited to individuals born in Denmark who were alive on or born after January 1st, 1981 (the beginning date for hospitalization data availability), lived (at least for some time) in Denmark between 1981 and 2004, and have complete information on the study variables.
The maximum follow-up time was 12 months from the index date, depending on enrollees' data availability.
However, due to the timeliness and data availability considerations, the majority of systems to date have focused on monitoring visit data from emergency department information systems.
Follow-up started at A1c measurement and ended at the time of death (outcome event), 7 days after transfer from the facility, or as of the date of most recent data availability (December 2011 or earlier), whichever came first.
To determine data availability, we measured the number of days between the date of the patient visit and the date of entry of the first diagnosis into the IDS's automated visit encounter database.
However, if Landsat data availability is sufficient to cover all phenologically important dates, we suggest relying solely on Landsat.
Here, our initial choice of environmental variables was based on factors previously shown to influence tree swallow laying date, but was also guided by data availability.
