As all interviews were carried out by the same person, the risk of differences in interpretation of answers was minimised.
The Cox-Regression analysis was used to evaluate the risk of differences between groups in the Kaplan-Meier survival analyses (hazard ratio).
This type of study design may be at risk of selection bias, but the choice of historical controls was made to allow comparability of interventions within a single clinical centre, thus removing the risk of differences in management between centres.
To eliminate the risk of differences between the hospitals and to obtain data from a broader perspective for profession, specialty, and wards we preferred individual randomisation over cluster randomisation.
The efforts were based on the concept that the risk of significant difference in bioavailability should be minimized if the dissolution profiles of the originator and generic product are similar under several test conditions.
The risk of baseline differences can be reduced using pair-matched randomization [ 33].
31 Studies evaluating the risk of behavioural differences in infants exposed to cannabis during pregnancy also have mixed results.
A control period of five winter and spring months vs. a full year intervention period provides a risk of seasonal differences in the trauma population.
More knowledge of differences in risk of revision for different diagnoses (and for different prosthesis designs) is still needed, and should be focused on in future studies.
"There is a risk of overstating the difference that American troops could make in the internal politics of Iraq," he said.
