Intended for healthcare professionals


Informed consent in biomedical studies on aging: survey of four journals

BMJ 1996; 313 doi: (Published 02 November 1996) Cite this as: BMJ 1996;313:1117
  1. Marcel G M Olde Rikkert, research fellowa,
  2. Henk A M J ten Have,
  3. Willibrord H L Hoefnagels, professor in geriatric medicine
  1. a Department of Geriatric Medicine, University Hospital Nijmegen, PO Box 9101, 6500 HB Nijmegen, Netherlands
  2. Department of Ethics, Philosophy, and History of Medicine, School of Medical Sciences, University of Nijmegen Henk A J M ten Have, professor of medical ethics.
  1. Correspondence to: Dr Olde Rikkert.

    International legislation requires that human subjects must give truly informed and free consent before participating in medical research. To achieve this, researchers must pay careful attention to the procedure for obtaining consent, especially in elderly subjects because of their high prevalence of impaired cognition, hearing, speech, and vision. Firstly, subjects judged incapable of giving consent must be excluded or consent by proxy obtained. There are, however, no well accepted standards for determining capacity to consent.1 Secondly, the information given should be matched to the reading ability and comprehension of the subjects studied.2 This requires a prior assessment of vision, hearing, and mental status. The approval of a study by the responsible ethics committee should, among other things, provide quality control of the consent procedure. We report here the first study to question how often approval of an ethics committee and obtaining consent were described in biomedical articles on aging.

    Methods and results

    Issues for 1993 and 1994 of the four journals with the highest impact factor in the category “geriatrics and gerontology” of the 1993 Science Citation Index were examined3: Journal of the American Geriatrics Society, Journal of Gerontology: Medical Section, Mechanisms of Ageing and Development and Age and Ageing. We found 586 articles reporting research in humans; case studies were excluded. We recorded the type of subjects, the study design, and whether informed consent procedures and approval of an ethics committee were mentioned. We also asked the editors of the four journals about their policies on these issues.

    Most studies (316) included elderly patients who were recruited from geriatric departments (76), nursing homes (82), or other hospital departments (158). The remaining studies included healthy elderly (170) and young or middle aged subjects (100). Data on consent procedures and ethics committee approval were present in only a minority of the studies (table 1). Obtaining consent was mentioned more often than approval, and both were most common in clinical trials. Eighteen studies used age or clinical diagnoses—for example, dementia, confusion, frailty—as criteria for incapacity to consent. Only two articles described the assessment of capacity to consent in more detail. The two editors who responded agreed that consent and approval of ethical committees should be published, but they considered that peer reviewers were primarily responsible for ensuring that this information was present. One editor stated that guidelines to referees would be changed because of our findings.

    Table 1

    Frequency of publication of informed consent and approval of an ethics committee according to study design in 586 biomedical studies on aging. Results are numbers of articles (and percentages)

    View this table:


    Overall the frequency with which information on informed consent and approval by an ethics committee were given was low. This does not necessarily imply that the required preconditions for ethically justified research were not met, simply that readers were not informed. None of the four journals required in their instructions for authors that this information should be given. However, three journals implicitly required information on approval by referring to the “Uniform requirements for manuscripts submitted to biomedical journals.”4

    We advocate that editors should explicitly state to authors and referees that approval of an ethics committee and obtaining subjects' informed consent are absolute preconditions for publication and should be mentioned in all papers reporting prospective research on human subjects. Additionally, authors should be more aware of their responsibility to publish relevant details of the assessment of capacity to consent and of special measures applied in informing elderly subjects. Articles should present more details about essential ethical issues to fulfil legal requirements, to ensure public accountability, to help spread the practice of new consent procedures, and to stimulate ethical and scientific debate.


    • Funding The Netherlands Programme for Research on Ageing (NESTOR), funded by the Ministry of Education, Culture and Sciences, and the Ministry of Health, Welfare and Sports.

    • Conflict of interest None.


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