Evaluation of participant comprehension of information received in an exercise and diet intervention trial: The DR's EXTRA study.
BACKGROUND
The informed consent process is the legal and ethical cornerstone of health research and is essential to ensure that participants in health research really understand the information they receive. Clinical studies often fail to provide data that clarify how much participants have understood.


OBJECTIVE
To evaluate the comprehension of older volunteer participants in health research.


METHODS
The subjects are a random population sample of 1,410 men and women aged 57-78 years, who are participating in a 4-year randomized controlled intervention trial on the effects of physical exercise and diet on atherosclerosis, endothelial function and cognition. A questionnaire about informed consent was given to all willing participants (n = 1,324) 3 months after the randomization. In addition, participants' long-term continuation in the intervention trial with relation to understanding was evaluated 2 years after the randomization.


RESULTS
The response rate was 91%. The majority of respondents (89%) were satisfied with the intelligibility of received information. In addition, the participants' comprehension of the information received seemed to be adequate in 82% of the whole study population. Compared to background variables, higher education (p < 0.001) and satisfaction with one's own health (p = 0.01) were associated with adequate comprehension of the provided information. Furthermore, participants who felt themselves to be healthy were more likely to continue participating in the intervention after 2 years.


CONCLUSIONS
The findings of this study indicated sufficient understanding of received information in older research participants. However, our results indicate that special efforts should be made with participants with lower educational levels or subjective feelings of impaired health. This study highlights the need for researchers to critically analyze the quality of information and how it is provided. This is especially important in long-term follow-up studies.
Länsimies-Antikainen
Helena
H
Department of Nursing Science, University of Kuopio, Kuopio University Hospital, Finland. ahantika@hytti.uku.fi
Pietilä
Anna-Maija
AM
Kiviniemi
Vesa
V
Rauramaa
Rainer
R
Laitinen
Tomi
T
D000367:Age Factors; D000368:Aged; D050197:Atherosclerosis / Q000523:psychology / Q000628:therapy; D003071:Cognition; D032882:Comprehension; D004032:Diet; D030881:Disclosure; D004522:Educational Status; D004730:Endothelium, Vascular; D015444:Exercise; D005260:Female; D006801:Humans; D007258:Informed Consent / Q000523:psychology; D008297:Male; D008875:Middle Aged; D010353:Patient Education as Topic; D017060:Patient Satisfaction