Helge Garåsen The Trondheim Model - NSDM

trial. Participating departments at the general hospital and staff at the community hospital had
no influence on the blinded randomising procedures which were performed at an independent
research unit at the Medical Faculty; Unit for Applied Clinical Research.
However, many chronically ill older patients regularly move backwards and forwards
between community and general hospital care with many short stays at general hospital each
year. As a consequence there might be a selection of individuals who were in need of longer
general hospital care. Even if the inclusion criteria were broader, the patients included to the
study represented those who were found eligible for the randomised controlled trial, and not a
random draw of all patients above 60 years of age admitted to the general hospital during the
trial period.
A weakness of the study might be that there are no records of how many patients were asked
to participate in the study but who refused to take part. There is neither any record of how
many patients actually refused inclusion nor of how many eligible patients were not asked to
participate in the study.
6.2.3. Confounders
In any study in which an outcome variable and an exposure variable are associated with a
third variable, adjustment may be necessary, provided that the association between the
outcome variable and the third variable (a possible confounder) is independent of the
exposure and not merely an intermediate link in the causation (128). In order to avoid
confounding factors distorting the apparent effects of intervention, adjustment were made.
The distribution between the groups was accounted for by the blinded randomisation
procedures. Still, there is sensibility for different diseases etc. The results were adjusted for
age, gender, diagnosis and ADL.
Other confounders could be social network, matrimonial status, differences in services in
different zones in the town, differences in collaboration with the general practitioner and the
patients’ mental capacities. Of these possible confounders only social network and
matrimonial status were monitored, there were no differences between the patient groups in
relation to these two factors. However, there are no indications that potential confounders
could be differently distributed between the patient groups.
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