Unlike our study in which data were collected prospectively, most studies have assessed the level of agreement between participants' retrospective reports and administrative data.
The data were collected prospectively in 40%, retrospectively in 26%, and the method was unclear for 31%.
We repeated the analyses, restricting this to persons reported prospectively from 1994.
Our findings highlight the difficulties in collecting information on seroconversion illness both retrospectively and prospectively.
One controversial debate in electoral studies is whether people judge the performance of a government retrospectively or prospectively.
As part of the cost-containment policy, all hospitals and other healthcare institutions are now required to have an overall annual budget, which is calculated prospectively.
Prospectively defined interaction with the sponsor facilitates unbiased design and conduct, but arrangements need careful implementation to avoid conflicts of interest.
However, the new coding should, prospectively, vastly improve the range and flexibility of existing categories.
