Section H. Role of the Patient
Chapter 48. Procedures For Obtaining Informed Consent
Chapter 49. Advance Planning For End-of-Life Care
Chapter 50. Other Practices Related to Patient Participation
Chapter 48. Procedures For Obtaining Informed Consent
Laura T. Pizzi, Pharm.D.
Neil I. Goldfarb
David B. Nash, M.D., M.B.A.
Thomas Jefferson University School of Medicine
and Office of Health Policy & Clinical Outcomes
The process of obtaining informed consent, whether a written
document or an oral communication, is one means of ensuring that patients
understand the risks and benefits of a treatment or medical intervention. Rooted
in medical ethics and codified as a legal principle, it is based on the
assertion that a competent individual has the right to determine what will or
will not be done to him or her.1 The American Medical
Association (AMA) Code of Medical Ethics establishes informed consent as an
ethical obligation of physicians.2 In addition to being an
ethical obligation of physicians, legislation in all 50 states requires that
patients be informed of all important aspects of a treatment and/or procedures,
although the details of these laws and statutes differ greatly.2 Failure to obtain adequate informed consent renders a physician
liable for negligence or battery3 and constitutes medical
To date, studies of informed consent have not investigated
outcomes related to the adequacy of the communication, insofar as this may
impact patient safety.4,5 Physician-patient communication
styles have been linked to lower rates of malpractice claims.6 Nonetheless, as noted by Levinson, malpractice claims do not
reflect the actual rate of negligence. While some have hypothesized that better
informed consent could improve the patient-physician relationship, establish
trust, increase patient compliance, and provide information that could reduce
medical error, this has not been shown.7,8 In the absence of
a direct link between adequate informed consent and the reduction of medical
error, the "patient safety outcome" reviewed in this chapter is the patient's
provision of adequate informed consent.
Informed consent is a process through which a physician informs
a patient about the risks and benefits of a proposed therapy and allows the
patient to decide whether the therapy will be undertaken.9
It may be received in one sitting, or over a period of time,7 either orally or in writing or a combination of the two.
Informed consent procedures have been instituted in both research and clinical
medicine. In the former case, federal regulations establish strict guidelines
for informed consent that are monitored by a special board at each institution
(Institutional Review Board). In addition, risks and adverse events that occur
while research is in progress are followed closely and reported. As such,
informed consent in the research setting differs greatly from informed consent
in the clinical setting.10
In clinical practice, formal efforts, such as the signing of a
consent form, (presumably preceded by adequate exchange of information), are
only undertaken in some circumstances, notably prior to major invasive
procedures such as radiologic procedures and surgery. Less well appreciated is
that all medical care, including pharmacy prescriptions or laboratory tests,
requires informal informed consent, except when the patient is incompetent to
make a decision or relinquishes the right to provide it.3
Studies suggest that in practice only minimal formal efforts are made to obtain
informed consent for routine interventions.11,12
Legislation governing the requirements of, and conditions under
which, consent must be obtained varies greatly from State to State. General
guidelines, such as those proposed by the AMA require patients to be informed of
the nature of their condition and the proposed procedure, the purpose of the
procedure, the risks and benefits of the proposed treatments, the probability of
the anticipated risks and benefits, alternatives to the treatment and the
associated risks and benefits, and the risks and benefits of not receiving the
treatment or procedure.2,3,13
As discussed below, procedures to obtain informed consent may
not adequately promote the patient's comprehension of the information provided,
rendering the consent not truly "informed." Interventions that may prove
beneficial in improving and ensuring the patient's understanding include
redrafting of consent forms to reduce complexity, providing written materials to
accompany oral conversations, using multimedia or other techniques to improve
comprehension, and asking patients to recap discussions about the
Prevalence and Severity of Target Safety Problem
Procedures to obtain consent must ensure that the patient
understands his or her condition, as well as the risk and benefits of treatment,
and its alternatives. It has been estimated that less than half of the US
population understands commonly used medical terms.14,15
This "health literacy" problem may impact the ability of the patient to
understand any attempts to obtain information. In addition to lack of
comprehension, procedures to obtain informed consent may be incomplete.
Several studies have noted the various insufficiencies in
procedures to obtain informed consent. Three studies examined the completeness
of physician-patient conversations in obtaining informed consent. Braddock et
al12 focused on outpatient discussions. Recognizing that
some procedures may require more discussion than others, they created a
three-tiered evaluation procedure, in which the completeness of
patient-physician discussions differ according to the complexity of the decision
being discussed. Basic decisions, such as laboratory tests, require the least
in-depth discussion, covering only the patient's role, the clinical nature of
the decision, and exploration of patient preferences. Intermediate decisions,
such as changes in medication, require a moderate depth of discussion,
incorporating the Tier 1 subjects, and adding a discussion of alternative
treatments, the risks and benefits of the alternatives, and an assessment of the
patients understanding. Complex decisions such as surgery require a discussion
of the uncertainties associated with the decision, in addition to all of the
aforementioned steps. Analyzing audiotaped conversations between 1057 patients
and 59 primary-care physicians and 65 surgeons, Braddock et al found that 17.2%
of basic decisions contained all required components, while none of the
intermediate decisions and only one of the complex decisions contained all of
the required components. Applying only the Tier 1 basic consent standards, 20.5%
of basic decisions, 21.9% of intermediate decisions, and 38.2% of complex
decisions met all the criteria.
In a study of informed consents of surrogates for pediatric
patients undergoing surgery, coders examined audiotaped conversations with
surrogates, as well as structured interview and questionnaire data regarding the
conversations. They noted that patients' recall of the conversations with
physicians often omitted key components, such as the risks and benefits of the
Bottrell et al13 examined the completeness
of 540 consent forms from 157 hospitals nationwide. Of these, 26.4% included all
four of the basic elements (risks, benefits, alternatives, and other important
aspects of the procedure). Eighty-seven percent noted the general possibility of
risk, but less than half provided specific information. Alternatives were noted
in 56.9% of the forms, and benefits appeared in 37%, though most of these were
general references rather than specific information. Although 74% of consent
forms were deemed incomplete, it is unknown whether physician-patient
discussions that preceded the signing of the consent form included the missing
A study by Mark et al9 found that 82.4% of
102 participants reported that they understood everything that their physicians
had described about a procedure and indicated that all of their questions had
been answered. Eighteen patients had remaining unanswered questions. Half of
this group requested more time to speak with their physicians, while the other 9
felt that their questions were not important.
In a study by Lavelle-Jones,17 69% of
patients admitted that they did not read a consent form before signing it. In
addition, approximately half of the patients awaiting treatment were unhappy
with the amount of information they received, with 21% stating that most of the
information they obtained about their surgical treatment was obtained outside of
Consent forms have been targeted for their lack of readability.
Patients with limited reading ability are at increased risk for medical errors,
due to problems reading medication bottles, appointment slips, self-care
instructions, and health education brochures.18 These
patients may also have trouble reading materials intended to aid in obtaining
informed consent. According to the National Adult Literacy Survey of 1993,
approximately 40-44 million Americans were functionally illiterate, defined as
the inability to complete basic reading tasks required to function as a member
of society.19 In addition, even in educated adults, the
highest grade-level completed may not reflect actual reading comprehension
level. A study of 100 adult cancer patients found that most read at a mean
grade-level equivalent of between 10th and 11th grade. The
authors suggest that forms and educational materials be written at a grade-level
three levels below the highest level of education completed by a patient.20
Several studies have examined the readability of procedure
consent forms. Two studies examined consent forms for radiologic procedures
using computer generated "readability" scores. Consent forms for use with
iodinated contrast media found that 12.35 years of education were required to
read consent forms.21 A similar study of general radiologic
procedure consent forms found that they required a mean of 15 years of
education. Only 16% of forms could be understood by patients with a high-school
education.11 Another Hopper et al study22 found that general hospital consent forms were written at a
grade level of 12.6. Just over half could be understood by a patient with a high
school education, less than a third by patients with a 10th grade
reading level, and just over 5% by patients with an 8th grade reading
Opportunities for Impact
While informed consent is a well-established practice, it often
fails to meet its stated purpose. Several methods of improving the procedures of
obtaining informed consent have been proposed, including improving the
readability of consent forms,22 asking patients for recall
to establish understanding,3,23 adding additional stimuli,
such as multimedia presentations24 and providing written
Lavelle-Jones17 found that elderly patients
(over 60 years of age) had poorer recall than younger patients. In addition,
patients with internal locus of control—those who believed their health was in
their own control—were better informed than those with an external locus of
control. Patients with above average IQ exhibited better recall. These findings
could indicate "at-risk" groups that interventions may target.
One author argues that an important opportunity for impact is
to change the model of implementing informed consent from a single event
approach to a process approach.7 Currently obtaining
informed consent often revolves around the signing of the consent form. Although
this approach clearly delineates the responsibility of healthcare providers,
provides documentation of the consent, and fits easily into the current provider
structure, it often results in patients failing to actually comprehend the
information and reinforces physicians' conception that the consent ritual is
futile. In contrast, a process model involves the physician providing
information over time, establishing a better patient-physician relationship and
better comprehension of medical care. As of yet there is no data to support
Since the definition of adequate informed consent is debatable,
the number of individuals currently not receiving interventions to obtain
adequate informed consent is likely to be quite high, but is not known.
Study Design, Outcomes and Effectiveness of Various
Improving Readability of Consent Forms and Education Materials
In order to ensure that patients understand the procedure to
which they are consenting, it is important that all materials be presented in a
comprehensible manner. Consent forms are written with relatively complex
sentence structure and vocabulary, making it difficult for the average adult to
interpret the information. In addition, providing consent forms in the primary
language of patients may improve consent procedures. However, we located no
studies examining the effectiveness of such practices.
Informed consent is often obtained during informal discussion
between physicians or nurses and patients, and (as discussed above), these
discussions frequently do not cover all of the relevant information.12 Two studies examined the use of a structured interview format
in providing information to patients. Solomon et al25
studied 36 patients receiving cardiac catheterization for the first time at a
Veterans hospital. Patients were randomized into two groups (Level 1 design).
Both groups were briefed by a cardiologist regarding the procedure (standard
care). In addition, the experimental group received a 30-minute structured
teaching session with a nurse to discuss all aspects of the procedure, including
the purposes, techniques, sensations, risks and benefits. Patients in the
experimental group also received an illustrated guide to cardiovascular
procedures and an educational pamphlet. All subjects were tested using a 13-item
questionnaire covering the information that should have been imparted during
informed consent procedures (Level 3 outcome). The intervention group scored
significantly better than the control group (11.5 vs. 8.9).
In a later study, Dawes et al26 studied 190
hospitalized patients undergoing ENT surgery. Patients were assigned to one of 4
groups. Groups 1 and 2 were assigned at different times (Level 2 design), while
groups 3 and 4 were randomly assigned (Level 1 design). Group 1 had no consent
interview until after assessment at the conclusion of the study. Group 2 engaged
in an informal interview with a physician (reflecting current practice), during
which the number of complications discussed was recorded. Group 3 engaged in a
structured interview with a physician, covering the purpose and technique of the
procedure, complications, sensations, alternatives, and benefits (a checklist
was used as a guide). The final group, Group 4, engaged in the same structured
interview, except that the patient was provided with a copy of the checklist and
allowed to take it with them after the interview. Patient anxiety was assessed
following consent using a visual analog scale, then reassessed at an interview,
given 4 hours later. At the later interview, patients were asked to recount
orally the operation name, describe what would be done, list complications, and
state whether they understood the information given to them (Level 3 outcome).
All but Group 1 (control group) patients showed a drop to normal anxiety after
informed consent. Group 2 (informal discussion) remembered proportionately more
complications mentioned in the informal interview, although fewer complication
were covered. Groups 3 and 4 recalled more total complications than Group 2.
There was no differences between Groups 3 and 4 (structured interviews).
Asking for Recall
A simple method of determining whether a patient understands
information regarding a procedure is to ask the patient to recount what he or
she has been told.3 Two studies examined this intervention,
using a randomized controlled trial design (Level 1 design). In the first study,
informed consent was solicited from 50 patients undergoing percutaneous lung
biopsy.23 Twenty-seven patients in the control group were
offered the standard procedure for obtaining informed consent: approximately 30
minutes prior to the procedure, the physician described the procedure in detail,
including its risks and benefits. Four complications were specifically
described, along with their relative risks. Patients were asked to sign a
standard consent form. Twenty-three patients received the same procedure, but in
addition, they were asked to describe all 4 potential complications. The
procedure was repeated until all patients in the intervention group could
recount all of the complications. This modified procedure usually took less than
5 minutes extra compared with the traditional approach. Patients were
interviewed 2 hours after the procedure was completed. Patients in the modified
consent group had better recall (Level 2 outcome) than patients in the control
group (56% vs. 14% with high recall (recalling 3-4 out of 4 risks), and 13% vs.
44% with low recall (recalling 0-1 out of 4 risks)).
A second study examined verbalization in 20 patients undergoing
anterior cruciate ligament (ACL) reconstruction.27 Patients
were randomly assigned to 2 groups. Both groups received the standard education
for ACL reconstruction, which included the use of a 3-D model of the knee,
discussion with a physician about the procedure, and obtaining informed consent.
The experimental group (8 subjects) also were asked to repeat back the risks of
the procedure until they could accurately recall all risks discussed. One-month
later, recall regarding the information received was tested using a 3-item
questionnaire (Level 2 outcome). All 8 in the experimental group answered all
questions correctly, while only four out of the 12 in the control group answered
all questions correctly (p=0.03).
Use of Visual or Auditory Learning Aids
Adding additional stimuli may increase the ability of the
patient to understand information being conveyed or increase retention of that
information. For instance, use of visual diagrams may make a procedure easier to
understand. Multi-media may also promote better comprehension. Three studies
have examined the addition of visual stimuli for informed consent. One study of
patients undergoing back surgery examined the impact of a diagnosis-specific
videodisk program on patient outcomes.24 Patients (n=393)
who were candidates for elective back surgery (primarily for herniated disc and
spinal stenosis) were randomized to two education groups (Level 1 design). The
control group received a written booklet regarding the surgical and non-surgical
treatments for herniated disc and spinal stenosis, a description of expected
outcomes, and a short self-test on the booklet information. Patients in the
experimental group also received the booklet, but in addition viewed a videodisk
program. The program allowed a patient to enter their diagnosis and age and
receive customized information on the alternative treatments, discussion of the
diagnoses (and the ambiguities of diagnosis), and interviews from patients that
had been treated surgically and non-surgically. At the end the patient was
provided with a printout of outcome probabilities. Patients in the experimental
group were slightly more likely to report that they had all the information they
wanted (Level 3 outcome). Rates of patients consenting to surgery for herniated
disk (32% vs. 47%) and other diagnoses (5.4% vs. 14.0%) were lower in the
Hopper et al28 also tested an interactive
video program, although the tested program was computer based. One-hundred and
sixty outpatients referred for IV contrast media studies were stratified by age,
sex, and previous exposure to contrast media, then randomized to receive either
a written consent form, or an interactive computer-based video (Level 1 design).
Subjects in the control group received a consent form designed to be read at an
eighth grade reading level. Subjects in the experimental group viewed a video in
which a physician used identical words as the consent form to inform subjects
about the procedure and risks. Subjects then had an option of hearing more about
the risks. If subjects chose not to hear additional information, they were
provided with printouts of the risks (with the minimal information already
given). Otherwise, subjects were provided with printouts certifying that they had
completed the program. All subjects were tested using a 7-item questionnaire
regarding the procedure and risks (Level 2 outcome). Patients that viewed the
video responded correctly more often than the control group when asked about
general aspects of the procedure. Female patients in the video group also
responded correctly more often to questions about risks, although this finding
did not hold for male patients. The video did take approximately 1.6 minutes of
additional time to complete, and there was no difference in patients desire for
additional knowledge between the groups (Level 3 outcome).
One final study did not use an interactive video, but tested
whether providing information via video was superior to providing information
via an informal discussion with the physician (standard practice).29 Two-hundred and twenty four subjects referred for colonoscopy
were stratified into previous or no previous colonoscopy, then randomized into 3
groups (Level 1 design). The control group had a structured discussion with a
physician, in which the physician covered the same information covered in the
video according to a checklist. The video-only group watched a 5-minute
videotape, in which a physician described the procedure, and its risk and
benefits. The third group (video and discussion), watched the video and then
engaged in a structured discussion with a physician. All patients were tested
using a 13-item questionnaire (Level 2 outcome). Both video groups gave more
correct responses than the discussion-only group, although they did not differ
from each other. In addition, patient anxiety levels were measured using the
State-Trait Anxiety Inventory (Level 3 outcome). There were no differences among
the 3 groups.
Providing Written Information to Patients
Providing written information to patients regarding their
diagnoses, proposed treatments, and other information given during informed
consent discussion allows the patient to refer back to such information, and
possibly increases comprehension. One early study compared the then-common
practice, informal interview between patient and doctor, with provision of a
written consent form.30 Eighty patients, referred for a
first excretory urography, were randomly assigned to 2 groups (Level 1 design).
The control group received standard care, the informal interview. The
experimental group received the same interview along with a detailed written
consent form to read and sign. Patient clinical reactions and side effects were
monitored (Level 1 outcome). One to 3 days after the procedures, patients
retrospectively rated discomfort, fear or apprehension, and understanding of the
procedure (Level 3 outcome). Patients also completed an 8-item knowledge
examination covering the information on the consent form (Level 2 outcome), or
in the informal interview. Experimental subjects scored significantly better
(p=<0.01) than control subjects for the knowledge exam (scoring 73% vs. 48%),
but did not differ in their discomfort, perception of the procedure, or
Some investigators have proposed that patients should receive
written consent forms days before receiving a procedure. Neptune et
al31 studied 160 subjects referred for a contrast media radiology
exam. The patients were stratified by age, sex, and previous exposure to
contrast media, and then were randomized within the strata into 2 groups (Level
1 design). The control group received a simple consent form (designed such that
it could be read with an eighth grade education), 15-60 minutes before the
procedure, consistent with standard care. Patients in the experimental group
received the same consent form 24-72 hours before the procedure, and were called
one day in advance to remind them to read the form. Subjects' knowledge
concerning their procedures was tested using a 7-item questionnaire (Level 2
outcome). Overall, there were no significant differences between the two groups
on either a knowledge or satisfaction score.
In a British study,17 265 patients
undergoing intrathoracic, intraperitoneal, or vascular procedures, were assigned
to one of 2 consent groups (Level 2 design). The control group was provided with
an oral explanation of their disease and the proposed procedures. Members in the
experimental group were provided with the same information, and also provided
with an "operation card" detailing the same information. Patients were given 30
minutes to review the cards before signing the consent form. Patients were
interviewed for recall (Level 2 outcome) immediately after consent (1 hour), the
day of discharge, 4-6 weeks post-discharge, and at 6 months post-discharge.
Control and experimental groups did not differ, except on the day of discharge
(p<0.0001). The only significant factor in predicting recall was the age of
the patient, as older patients had poorer recall than younger patients, even
when controlling for psychological factors. Written information did not appear
to aid in recall for older patients at any time point.
Two other studies provided written information to patients,
although this was combined with structured teaching programs. These studies are
reviewed under "Structured Discussions" above.25, 26
While much has been written regarding informed consent and the
ethical obligations of providers to obtain proper informed consent, serious
shortcomings have been reported. However, very little literature has examined
the impact of different procedures for obtaining informed consent on the quality
of the consent obtained. The weight of the literature suggests that the value of
informed consent can be modestly enhanced by augmenting standard
provider-patient discussions with additional learning and retention aids
(written or videodisk materials). Moreover, the process of consent can be mildly
improved by using structured interviews and by asking patients to recall and
re-state key elements of the discussion. In addition to the ethical imperative
of informed consent, it may be that informed patients are less likely to
experience medical errors by acting as another layer of protection (as when a
patient is able to inform providers about his or her correct medications or the
correct surgical procedure he or she is to undergo). More research is needed to
establish the best practices to improve informed consent, and to test the impact
of such practices on patient safety.
1. Edwards SJ, Lilford RJ, Thornton J, et al. Informed consent for clinical
trials: in search of the "best" method. Soc Sci Med 1998;47:1825-40.
2. American Medical Association. Informed consent. American Medical
Association. April 11, 2001.
3. Pape T. Legal and ethical considerations of informed consent. AORN
4. Stewart MA. Effective physician-patient communication and health outcomes:
a review. CMAJ 1995;152:1423-33.
5. Greenfield S, Kaplan S, Ware JE, Jr. Expanding patient involvement in
care. Effects on patient outcomes. Ann Intern Med 1985;102:520-8.
6. Levinson W, Roter DL, Mullooly JP, et al. Physician-patient communication.
The relationship with malpractice claims among primary care physicians and
surgeons. JAMA 1997 Feb 19; 277(7): 553-9.
7. Lidz CW, Appelbaum PS, Meisel A. Two models of implementing informed
consent. Arch Intern Med 1988;148:1385-9.
8. Kuyper AR. Patient counseling detects prescription errors. Hosp
Pharm 1993;28:1180-1, 1184-9.
9. Mark JS, Spiro H. Informed consent for colonoscopy. A prospective study.
Arch Intern Med 1990;150:777-80.
10. Code of Federal Regulations. Title 45: Public Welfare. Revised June 18,
1991. Effective August 19, 1991.
11. Hopper KD, TenHave TR, Hartzel J. Informed consent forms for clinical and
research imaging procedures: how much do patients understand? AJR Am J
12. Braddock CH, 3rd, Edwards KA, Hasenberg NM, et al. Informed decision
making in outpatient practice: time to get back to basics. JAMA
13. Bottrell MM, Alpert H, Fischbach RL, et al. Hospital informed consent for
procedure forms: facilitating quality patient-physician interaction. Arch
14. Boyle CM. Difference between patients' and doctors' interpretation of
some common medical terms. Br Med J 1970;1:286-9.
15. Cole R. The understanding of medical terminology used in printed health
education materials. Health Educ J 1979;38:111-21.
16. Lashley M, Talley W, Lands LC, et al. Informed proxy consent:
communication between pediatric surgeons and surrogates about surgery.
17. Lavelle-Jones C, Byrne DJ, Rice P, et al. Factors affecting quality of
informed consent. BMJ 1993;306:885-90.
18. Baker DW, Parker RM, Williams MV, et al. Health literacy and the risk of
hospital admission. J Gen Intern Med 1998;13:791-8.
19. Kirsch I, Jungblut A, Jenkins L, et al. Adult literacy in America: a
first look at the results of the national adult literacy survey. Washington, DC:
National Center for Education, US Department of Education; 1993.
20. Jubelirer SJ, Linton JC, Magnetti SM. Reading versus comprehension:
implications for patient education and consent in an outpatient oncology clinic.
J Cancer Educ 1994;9:26-9.
21. Hopper KD, Lambe HA, Shirk SJ. Readability of informed consent forms for
use with iodinated contrast media. Radiology 1993;187:279-83.
22. Hopper KD, TenHave TR, Tully DA, et al. The readability of currently used
surgical/procedure consent forms in the United States. Surgery
23. White CS, Mason AC, Feehan M, et al. Informed consent for percutaneous
lung biopsy: comparison of two consent protocols based on patient recall after
the procedure. AJR Am J Roentgenol 1995;165:1139-42.
24. Deyo RA, Cherkin DC, Weinstein J, et al. Involving patients in clinical
decisions: impact of an interactive video program on use of back surgery. Med
25. Solomon J, Schwegman-Melton K. Structured teaching and patient
understanding of informed consent. Crit Care Nurse 1987;7:74-9.
26. Dawes PJ, O'Keefe L, Adcock S. Informed consent: the assessment of two
structured interview approaches compared to the current approach. J Laryngol
Otol 1992; 106:420-4.
27. Wadey V, Frank C. The effectiveness of patient verbalization on informed
consent. Can J Surg 1997;40:124-8.
28. Hopper KD, Zajdel M, Hulse SF, et al. Interactive method of informing
patients of the risks of intravenous contrast media. Radiology 1994;192:67-71.
29. Agre P, Kurtz RC, Krauss BJ. A randomized trial using videotape to
present consent information for colonoscopy. Gastrointest Endosc
30. Winfield AC, Ford CV, James AE, et al. Response of patients to informed
consent for excretory urography. Urol Radiol
31. Neptune SM, Hopper KD, Houts PS, et al. Take-home informed consent for
intravenous contrast media: do patients learn more? Invest Radiol
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