[Appendix A]
Evidence Review: Informed Consent in Practice
While much of the clinical literature evaluating what works and what doesn’t work in informed consent
comes out of the clinical research setting, many of the broader “lessons learned ” in these studies are highly applicable to the setting of everyday informed consent.
How often does informed consent work as intended? How do the practices within your institution match up to the national norms for informed
consent? For that matter, how does one even begin to measure the “success ” of informed consent? These are complex questions that have been tackled by
clinicians and researchers from different settings and perspectives. Many studies have focused on one therapeutic area of interest. Others have analyzed
the consent process only in the research setting. And some have evaluated the process in targeted patient groups such as those with low literacy.
A review of results from such studies will provide the clinician and healthcare administrator with a sense of the problems that must still be overcome in
planning for and delivering informed consent in everyday clinical practice. All too often, the only metric used to monitor the informed consent process in
busy hospitals and clinics is the number of complaints or litigation. The results described below suggest that the squeaky wheel method of monitoring success
is inadequate for improving quality, safety, and patient satisfaction.
Evaluating the Process
Braddock et al 1999: Audiotape recordings from 1057 physician-patient encounters were analyzed for completeness
of information needed to make informed decisions; overall, only 9% of decisions were completely informed, while only 20% to 38% of the situations met less
stringent criteria for completeness.
Manthous et al 2003: A national mailed survey of 117 intensivists and 56 internists revealed heterogeneity in the practice of obtaining informed consent in several
common procedures. While consent was uniformly low for Foley catheterization (<10%) and uniformly high for endoscopic procedures (>90%),
the rates of obtaining consent ranged from 74% to 93% for transfusion of blood products and from 77% to 96% for common diagnostic procedures
such as lumbar puncture or paracentesis; further, many physicians used a blanket consent form to cover invasive medical procedures performed
during the hospital stay.
Mark et al 1990: A prospective survey of 102 patients undergoing colonoscopy found that 82% understood everything they were told
and had all their questions answered.
Saw et al 1994:Interviews with 55 men who had undergone transurethral resection of the prostate showed that 18% could not recall
that retrograde ejaculation was a major risk of the procedure (despite emphasis on this in the informed consent).
Sudore 2006: A descriptive study of a modified consent process with 204 ethnically diverse elderly patients
(40% with low literacy) found that only 28% answered all comprehension questions correctly. After a second round of education,
80% answered correctly. Low literacy and being black were associated with need for more education.
Evaluating the Written Form
Bottrell et al
2000: The content of 540 informed consent forms
from 157 hospitals was analyzed for four required key elements
(nature of procedure, risks, benefits, alternatives); only
26% of the forms included all four elements; less than half
the forms provided specific information about risks; alternatives
were noted only in 57% of forms.
Davis et al. 2001: Focus
groups with patients with limited education and low income
showed that 60% could not understand a standard informed
consent form related to screening for colorectal cancer.
Eisenstaedt 1993: A survey of 81 hospitals
in the mid-Atlantic region found that only 50 (62%) required
informed consent for blood transfusions; further, these
forms were not standardized and often missed key elements
such as risks and benefits, alternatives, and confidentiality.
For example, only 27 of 48 forms mentioned complications.
The reading level of 34 submitted forms was grade 14.6.
Hopper et al. 1998:In one of the largest
evaluations of informed consent forms to date, 616 forms
from around the U.S. were assessed by computer for readability;
of the 616 total forms, 29 were at <8th grade level and
461 were at >12th grade level.
Lavelle-Jones et al 1993:Interviews of
250 patients undergoing intrathoracic, intraperitoneal,
or vascular surgery revealed that 69% of patients said they
did not read the consent form before signing it; about half
of the patients awaiting treatment said they were unhappy
with the amount of information they received.
Bergler et al 1980: In multiple-choice
quizzes of patients who had entered a clinical trial for
blood pressure medications after reading an informed consent
statement, the correct response rate was 72% at 2 hours
and 62% at 3 months.
Dawes 1994:A survey of 50 patients after
surgery found that the purpose of consent forms is often
unclear and patients frequently perceive them as a form
of legal protection for hospitals and treatment centers
rather then as a source of information. For example, more
than two thirds of patients thought the form they were signing
was a legal document and 50% worried about some aspect of
their surgery.
Estimating the Consequences
of Poor Disclosure
Some studies support
the intuitive notion that better patient-physician communication
will lead to improved long-term health outcomes. One analysis
of randomized controlled trials on patient-physician communication,
for example, showed that the quality of the overall communication
(e.g., in history taking or treatment discussion) influenced
patient outcomes such as emotional health, symptom resolution,
blood pressure, or blood sugar levels in 16 of 21 studies.
[Stewart 1995] Similarly, individual studies have correlated
improved communication with increased adherence, [Bull 2002]
lower levels of medical mishaps, [Sutcliffe 2004] and reduced
malpractice claims. [Levinson 1997]
However, it must be emphasized that there are no large and
well-designed studies directly correlating better informed
consent to better clinical outcomes such as lower rates
of medical errors. As indicated in the studies summarized
in the previous section, most of the current evidence base
involves the link between informed consent quality and patient
comprehension, recall, or attitudes. For example, in an
extensive analysis of the impact of one specific effort
to improve informed consent, several “success stories”
were reported but the results were mainly anecdotal or process-oriented.
[NQF 2005] While such surrogate outcomes of patient understanding
and comfort level are hypothesized to be important in avoiding
errors, in boosting compliance and recovery, and in strengthening
the doctor-patient relationship, this has not been shown.
[Pizzi 2001]
Nevertheless, based on the belief that informed consent
is not only a legal requirement but also a critical just-in-time
component of improved patient-physician communications,
many institutions and individual clinicians or clinics have
initiated efforts to improve their policies and procedures
for informed consent. [NQF 2005] As recently summarized
by the National Quality Forum, [NQF 2005] the consequences
of a poor informed consent process might include:
Increased chance of a patient safety incident or medical
error
Increased chance for malpractice cases
Violation of professional and ethical obligation to
clinicians to communicate clearly
Developed with a grant from the Robert Wood Johnson Foundation