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J R Soc Med. 2002 December; 95(12): 601–603.
PMCID: PMC1279286

How much do doctors know about consent and capacity?

Elizabeth Jackson, MRCPsych and James Warner, MD MRCPsych1


To assess knowledge of capacity issues across different medical specialties we conducted a cross-sectional survey with a structured questionnaire at academic meetings, lectures and conferences.

Of 190 individuals who received the questionnaire 129 (68%) responded—35 general practitioners, 31 psychiatrists, 29 old-age psychiatrists and 34 final year medical students. Correct answers on capacity to consent to or refuse medical treatment were given by 58% of the psychiatrists, 34% of the geriatricians, 20% of the general practitioners and 15% of the students. 15% of all respondents wrongly believed that a competent adult could lawfully be treated against his or her will, with no obvious differences by specialty.

As judged by this survey, issues of capacity and consent deserve more attention in both undergraduate and postgraduate medical education.


With the introduction in the UK of the Human Rights Act1 there is increasing public awareness of individual rights, and in the medical setting people are encouraged to participate actively in decisions regarding their care. A recent case that received wide attention was that of B, a competent adult whose right to refuse treatment was sustained even though the decision might hasten her death2. Earlier, the ground-rules for ‘consent’ had been laid down in two cases. In the case of C (concerning whether a man with schizophrenia had capacity to refuse consent to amputation of his gangrenous foot)3 the High Court stipulated that an adult has capacity to consent (or refuse consent) to medical treatment if he or she can understand and retain the information relevant to the decision in question, believe that information, and weigh that information in the balance to arrive at a choice. For capacity to consent to research, the criteria are similar. Those that must be fulfilled for testamentary capacity (making a will) were set out by the Lord Chief Justice following the case of Banks v Goodfellow4. These are in effect: the testator should understand what a will is and what its consequences are; he/she knows the nature and extent of his/her property; he/she appreciates who may reasonably expect to have a claim to the property; he/she is free from an abnormal state of mind that might distort feelings or judgments relevant to the making of the will.

Doctors daily make judgments regarding their patients' competency to consent to medical investigation and treatment; and in today's litigious climate they must face the possibility that, from time to time, these decisions will be examined critically in a court of law. Capacity fluctuates with both time and the complexity of the decision being made; thus, sound decisions require careful assessment of individual patients. A doctor could be held negligent for not properly assessing capacity if the patient was harmed by treatment (or non-treatment). A recent survey indicates that junior doctors are uncertain of the issues; of surgical senior house officers, three-quarters of those questioned felt a need for more training on these matters5.

To assess doctors' judgments on capacity, researchers have used clinical vignettes or audiotapes of consultations6. So far as we know, however, no-one has reported assessment of the knowledge-base on which decisions are made. We examined doctors' knowledge across a range of subjects and groups.


The participants were chosen from specialties that regularly care for patients in whom capacity issues may be relevant—psychiatrists, general practitioners, geriatricians. We also included medical students in their last year of training, since the issues arise in the work of house officers. The students were recruited in a revision lecture before their final year examinations. Psychiatrists were recruited at clinical academic meetings, at a medical staff committee meeting within a London mental health trust or at an educational conference for specialist registrars; geriatricians were recruited at clinical academic meetings at three teaching hospital sites in inner London; general practitioners all participated during a conference on medical education.

A structured questionnaire was designed to assess knowledge needed to make valid decisions about capacity in seven separate areas (consent/refusal of medical treatment; consent to research; testamentary capacity; driving; managing financial affairs; sexual relationships; voting). All questionnaires were to be completed and returned in the presence of the researcher (EJ), to prevent cheating either by collaboration or by collection of information. The questionnaire was piloted with 15 respondents but no important modification was needed. Participants were offered a set of correct answers after data collection was completed. The questionnaire and answers were based on published guidance for doctors from both the Law Society and the British Medical Association7. Respondents were asked for information on basic demography, training and specialty. Most questions had a multiple-choice format (yes/no/don't know). Participants were also asked to specify what three criteria would need to be assessed when evaluating capacity to consent or refuse medical treatment and capacity to consent to research, and what four criteria were needed for testamentary capacity. These answers were scored independently by both EJ and JW, and any discrepancies were resolved by consensus. We scored leniently, looking for a general understanding of the criteria outlined above. When participants gave two or three of the three criteria needed for capacity to consent to treatment or research, the responses were scored correct. Zero or one were considered incorrect. Answers that gave three or four of the four criteria for testamentary capacity were similarly marked as correct.

Data were analysed by SPSS 10.0. Differences between groups were evaluated by chi-square test or Fisher's exact test as appropriate.


129 (68%) of the 190 individuals who received questionnaires returned them fully completed—34 medical students, 35 general practitioners, 31 psychiatrists and 29 old-age physicians. Of the group differences shown in Table 1, only two were statistically significant—the greater tendency for the psychiatrists to be involved in research (P=0.01) and the more recent qualification of the general practitioners (P<0.001).

Table 1

18 psychiatrists (58%) were correct in their knowledge regarding capacity to consent or refuse medical treatment, compared with 10 geriatricians (34%), 7 general practitioners (20%) and 5 students (15%) (P=0.001). Of the 129 participants, only 34 were actively involved in research. Of these, 27 (79%) did not know the criteria for assessing capacity to consent to research. Regarding testamentary capacity, none of the students or geriatricians and only 1 general practitioner and 8 psychiatrists responded correctly.

Of the junior doctors, 5/16 (31%) were correct in knowledge about capacity to consent or refuse treatment, compared with 4/10 (40%) of non-career-grade doctors, 12/19 specialist registrars (63%), 7/15 consultants (47%) and 7/35 general practitioners (20%). On consent for research, correct answers were given by 2/16 junior doctors (13%), 3/10 non-career-grade doctors (30%), 7/19 specialist registrars (37%), 5/15 consultants (33%) and 4/35 general practitioners (11%).

Knowledge regarding testamentary capacity was also poor, irrespective of seniority. None of the 16 junior doctors was well informed, and correct answers were given by only 2/10 non-career-grade doctors (20%), 3/19 specialist registrars (16%), 3/15 consultants (20%) and 1/35 general practitioners (3%).

Results for some of the more structured questions are shown in Table 2. Data were complete for the first two questions (treatment under common law and under the Mental Health Act) but some respondents chose not to answer certain questions—1 general practitioner on driving; 1 general practitioner and 1 psychiatrist on voting; and 2 general practitioners, 1 geriatrician, 3 psychiatrists and 4 students on sexual relationships. Amongst psychiatrists, knowledge about eligibility to vote while detained under the Mental Health Act did not differ by grade (P=0.33).

Table 2
Responses to individual questions


Although doctors are commonly involved in assessing capacity issues, our findings indicate that the knowledge-base is deficient. Even some consultant psychiatrists, who may be asked to give expert opinions on these matters, were found wanting. 15% of respondents believed they could forcibly treat an individual who refused.

What are the weaknesses of this survey? First, a response rate of only 68% raised the likelihood of bias. However, we suspect that this resulted in a better rather than worse view of doctors' knowledge, since non-respondents would be less confident than respondents. Similarly, the recruitment in educational settings probably gave an overestimate of doctors' knowledge by selecting those who were motivated and well-informed. The lack of significant differences across grades and other subgroups may reflect the small numbers.

From this survey we judge that doctors' knowledge of capacity issues is at present far from adequate. Better education is needed at both undergraduate and postgraduate levels. This may be an area to include within individual personal development plans, with support from trusts and primary care groups.


1. Human Rights Act 1998. London: Stationery Office, 1998
2. Re B (Medical Treatment: Right to Refuse). Family Law Reports 2002: 402
3. Re C (Adult: Refusal of Treatment) 1. All England Reports 1994: 819
4. Banks v Goodfellow (1870) LR 5 QB 549
5. Cowan J. Consent and clinical governance: improving standards and skills. Clin Perform Qual Health Care 2000;8: 124-8 [PubMed]
6. Braddock CH, Fihn SD, Levinson W, Jonsen AR, Pearlman RA. How doctors and patients discuss routine clinical decisions. J Gen Intern Med 1997;12: 339-45 [PMC free article] [PubMed]
7. A Report of the British Medical Association and the Law Society: Assessment of Mental Capacity, Guidance for Doctors and Lawyers. London: BMA Publishing, 1995

Articles from Journal of the Royal Society of Medicine are provided here courtesy of Royal Society of Medicine Press