Impact of written information on knowledge and preferences for
Ian H Kerridge, Sallie-Anne Pearson, Isobel E Rolfe, Michael Lowe and
John R McPhee
MJA 1999; 171: 239-242
More articles on Ethics
Aim: To investigate knowledge about and attitudes to
cardiopulmonary resuscitation (CPR), and to determine whether
written information about CPR alters knowledge and choices
Design: Questionnaire-based survey before and
immediately after provision of written information describing CPR
and its risks and benefits.
Subjects and setting: All health professionals (803) and
competent inpatients (260) in a tertiary care hospital (John Hunter
Hospital, Newcastle, New South Wales, Australia) in June 1994.
Main outcome measures: CPR knowledge scores and choice
scores (number of hypothetical clinical scenarios in which CPR would
be chosen) before and after provision of information about CPR.
Results: Response rates were 64% (health
professionals) and 58% (patients). Patients had limited awareness
of procedures involved in CPR, while both patients and health
professionals overestimated its success rates. Mean knowledge
scores increased after provision of information: for patients, from
6.4 out of 18 (95% confidence interval [CI], 6.0-6.9) to 10.4 (95% CI,
9.9-11.1); and for health professionals, from 11.9 (95% CI,
11.7-12.1) to 13.9 (95% CI, 13.7-14.2). In contrast, mean choice
scores decreased after provision of information: for patients, from
5.3 out of 12 (95% CI, 4.7-5.7) to 4.4 (95% CI, 3.9-4.8); and for health
professionals, from 4.1 (95% CI, 3.9-4.2) to 3.5 (95% CI, 3.3-3.7).
Conclusion: Our results imply that people understand and
use prognostic information to make decisions about CPR. To make
autonomous judgements, patients and health professionals need
better education on CPR outcomes.
While cardiopulmonary resuscitation (CPR) can be lifesaving,
success rates (survival to discharge) are less than 5% in some types of
patients, particularly those with chronic illness or multiple
comorbidities.1 Among those who survive,
quality of life is often poor and life expectancy often
short.2 In the mid-1970s, growing
concern about inappropriate application of CPR and increased
awareness of patient rights led to the development of
"do-not-resuscitate" (DNR) orders.3 Health professionals are
now increasingly encouraged to discuss DNR decisions with patients
and their families.4 However, for
decision-making about CPR to be appropriate, patients and their
surrogates must have some understanding of the likelihood of
surviving CPR and the possible adverse effects.
Previous research has found that 50%-80% of patients claimed
awareness of CPR, but their knowledge was very limited and derived
mainly from television dramas. Most patients believed erroneously
that CPR is generally successful,5,6 and both patients and
health professionals were found to overestimate its success by up to
We aimed to investigate knowledge of and attitudes to CPR among
hospital inpatients and health professionals and to determine
whether written information about CPR alters knowledge and
preference for CPR. We have previously reported the opinions of
patients and health professionals on the process of decision-making
Subjects and setting|
The study was conducted at the John Hunter Hospital, Newcastle, New
South Wales (a 530-bed tertiary care hospital), over a four-day
period in June 1994. Subjects comprised all health professionals
working in the hospital (doctors, nurses and allied health
professionals) and all eligible (competent) inpatients, as
described previously.8 Informed consent was
obtained by trained interviewers, and a Mini Mental State
Examination (MMSE) performed on patients. Those with MMSE scores
< 24 were excluded. A questionnaire for self-completion was
administered before and immediately after provision of written
information about CPR.
The questionnaire asked about:|
- sources of information on CPR (respondents could nominate as many as
applied from a list of 11);
- whether each of 10 procedures is part of CPR (possible answers: yes,
no or don't know);
- how successful CPR is in eight clinical scenarios, using a
five-point scale: rarely (< 5%), seldom (5%-30%), sometimes
(31%-60%), mostly (61%-90%) or almost always (> 91%); and
- whether respondents would like CPR performed on themselves in 12
specific clinical scenarios (possible answers: yes or no).
On completing the questionnaire, respondents were given a one-page
information sheet that explained various aspects of CPR, including
its definition, procedures that may or may not be considered part of
CPR, risks and benefits, success rates, and prognostic indicators
(good prognosis: after acute myocardial infarction; poor
prognosis: cancer, severe infection, organ failure). Respondents were then asked to repeat the questions on knowledge
Data were analysed with SPSS version 6.0 for Windows.9
Sociodemographic characteristics of patients and health
professionals were compared using continuity-corrected
analyses. All other analyses were performed for patients and health
Knowledge of CPR was scored by allocating a point for each correct
response. We assessed the relationship between this score and
sociodemographic characteristics by standard multiple linear
regression, with knowledge score as the dependent variable. For this
analysis, we converted the discrete sociodemographic variable
(health professional background) into a set of dichotomous
independent variables using dummy variable coding (ie, doctors
versus all other health professionals, and nurses versus all other
health professionals). Significance of change in knowledge scores
after provision of information was examined by one-way
repeated-measures analysis-of-variance (ANOVA). As answers to
some of the knowledge questions may be contentious (whether CPR
involves intravenous drugs, intubation and defibrillation),
analyses were repeated using scores with these questions omitted.
Composite "choice scores" about CPR were calculated by allocating a
point for each condition in which the subject would choose to have CPR.
The relationship between choice score, sociodemographic
characteristics and knowledge score after provision of information
was assessed by standard multiple linear regression, with choice
score as the dependent variable and knowledge score and
sociodemographic factors as independent variables. Significance
of change in choice scores after provision of information was
examined by ANOVA.
The study was approved by the Hunter Area Health Service Research
Ethics Committee and the University of Newcastle Human Research
Of the 803 questionnaires delivered to health professionals, 511
(64%) were returned (148 from doctors, 312 from nurses and 51 from
allied health professionals). Of the 443 adult patients in the
hospital during the study, 183 were excluded (because of dementia,
neurological impairment or delirium , incompetence as
assessed by MMSE , visual or language problems , psychiatric
illness , or as they were undergoing procedures ); 153 (58%) of
the remaining 260 completed the questionnaire. Sociodemographic
characteristics of respondents are shown in Box 1.
Knowledge about CPR|
Sources of information about CPR most commonly identified by health
professionals were first aid or in-service courses (33% of
responses); school, college or university (27%); and other health
professionals (17%). Sources most commonly identified by patients
were television (28% of responses), books or magazines (15%), first
aid classes (15%), and school (10%).
Knowledge before provision of information is shown in Box 2.
Patients' knowledge scores were low (mean, 6.4 out of 18; 95%
confidence interval [CI], 6.0-6.9), mainly because of lack of
awareness of success rates of CPR, with 90% overestimating success
for the "all patients" category. Health professionals' knowledge
scores were higher than patients' (mean, 11.9; 95% CI, 11.7-12.1),
but health professionals also overestimated success of CPR, with 65%
overestimating success for "all patients". ANOVA showed that
knowledge scores improved significantly after provision of written
information for both patients and health professionals (patients:
mean, 10.4; 95% CI, 9.9-11.1; health professionals: mean, 13.9; 95%
The only sociodemographic characteristics that significantly
predicted knowledge scores before provision of information were age
(for patients) and professional background (for health
professionals): younger patients achieved higher scores
than older patients, while doctors and nurses achieved higher scores
than allied health professionals. Repeat analysis of the data after
omission of contentious questions did not affect the relationship
between sociodemographic variables and knowledge scores or the
change in knowledge scores after provision of information.
Choices about CPR||
Percentages of patients and health professionals who chose CPR are
shown in Box 3. Percentages varied between clinical scenarios, but
decreased after provision of information for almost all. ANOVA
showed that choice scores also decreased significantly for both
patients and health professionals. Mean choice scores decreased for
patients from 5.3 out of 12 (95% CI, 4.7-5.7) to 4.4 (95% CI, 3.9-4.8),
and for health professionals, from 4.1 (95% CI, 3.9-4.2) to 3.5 (95%
CPR was chosen for more scenarios by patients who were younger or had
lower knowledge scores and by health professionals who were younger,
male, tertiary educated or had better self-reported health status.
We found that patients in an Australian teaching hospital had poor
knowledge of CPR, and that both they and, to a lesser extent, hospital
staff had unrealistic expectations about its success rates. We also
found that provision of written information about CPR risks,
benefits and success rates had a clear impact on whether patients and
health professionals reported wanting CPR performed on themselves
in hypothetical clinical scenarios, decreasing their preference
Other studies have also found that patients are unaware of the
procedures involved in CPR and, along with their relatives,
generally overestimate success rates.10 This is not surprising, as
television, books and magazines are often their most common sources
of information. In addition, community education tends to be
positive about CPR, often failing to describe its real success rates.
Several previous studies have investigated the relationship
between choices about CPR and estimated probability of
survival.5,11 They found, similarly to
us, that many patients change their minds about wanting CPR when they
learn the true probability of survival. Furthermore, formal
processes of information disclosure, including discussion of the
likely outcome of resuscitation in specific clinical situations,
has been shown to modify preferences for CPR.12 In our study, the change in
preference followed provision of a one-page information sheet. It is
possible that a more optimal form of education (eg, repeated
explanations tailored to the individual, with time for reflection
and questions) would have produced a greater change in
Perceived morbidity after CPR also strongly influences many
people's choices. A survey of 200 medical inpatients found that
choice of CPR or DNR status was strongly influenced by anticipated
outcome; 90% of patients desired CPR if they were to be restored to
their normal health, 30% if the likely outcome after recovery was
dependence, 15% if it was perceived as "hopeless", and 6% if it was
coma.13 Other studies from the
United States14 and United
Kingdom15 have found that senile
dementia, more than any other condition, is associated with a
preference for DNR status. We found similarly that patients and
health professionals would be unlikely to opt for CPR in the presence
of brain injury or severe dementia. Nevertheless, as found by
others,6,10 some patients continued
to opt for CPR even if they were likely to have a serious disability,
such as coma or terminal illness.
We also found, in common with others overseas, that health
professionals vastly overestimate the success rates of CPR. These
rates (3%-30% in general hospitals) have not changed significantly
in the past 30 years.1,16 However, they are well
below the rates perceived by physicians and nurses, who are
responsible for making decisions about resuscitation status and
informing patients and their surrogates.17,18
There are several limitations to our study. Subjects included
hospitalised patients with acute illness, and the findings may not be
generalisable to other patient populations. The study instrument
was a self-report questionnaire using hypothetical clinical
scenarios; answers may not accurately reflect what individuals
would choose in reality. However, the study has strengths; it
assessed both knowledge of and attitudes to CPR in variable clinical
contexts and included a formal assessment of competence (the MMSE).
The study also used trained interviewers rather than clinicians to
distribute questionnaires and so was less likely to
introduce bias and perhaps more likely to elicit patients' true
As factors such as likelihood of survival and functional status after
resuscitation may contribute to patients' wishes for CPR, it is
ethically and clinically desirable that patients be provided with
this information. Furthermore, the High Court of Australia has
reaffirmed that patients must be given adequate information when
making decisions concerning their healthcare.19,20 It is also
essential that health professionals who advise patients are aware of
the real success rates of CPR. Otherwise, they have failed to meet the
standards required both for ethical medical care and by
Respect for autonomy demands that the views of patients or their
surrogates should be sought in decision-making about CPR. Our study
implies that patients understand and use prognostic information in
their decision-making. For truly autonomous judgements, patients
and health professionals clearly need better education on risks and
benefits of CPR.
We would like to thank the interviewers and patients and staff of the
John Hunter Hospital for their generous participation in this study.
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Rabkin MT, Gillerman JD, Rice NR. Orders not to resuscitate. N
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Miller DL, Jahnigen DW, Gorbien MJ, Simbarti L. Cardiopulmonary
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Schonwefter RS, Walker RM, Kramer DR, Robinson BE. Resuscitation
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Murphy DJ, Burrows MD, Santilli S, et al. The influence of the
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Schonwetter RS, Teasdale TA, Taffet G, et al. Educating the
elderly: cardiopulmonary resuscitation decisions before and after
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(Received 13 Jan, accepted 7 Jul, 1999)
Faculty of Medicine and Health Sciences, University of Newcastle,
Ian H Kerridge, MPhil, Lecturer in Clinical Ethics;
Sallie-Anne Pearson, PhD, Research Academic;
Rolfe, MMedEd, Senior Lecturer in Medical Education;
Michael Lowe, FRACP, Tutor in Clinical Ethics;
John R McPhee,
BCom(Hons) (Legal Studies), Consultant in Health Law.
Reprints will not be available from the authors.
Correspondence: Dr I
H Kerridge, Clinical Unit in Ethics and Health Law, Locked Bag 1,
Hunter Region Mail Centre, Newcastle, NSW 2310.
|1: Sociodemographic characteristics of patients and health professionals surveyed about cardiopulmonary resuscitation|
|Healthcare professionals |
|Age > 35 years*||90 (59%)||235 (46%)||
|Female||98 (65%)||373 (73%)||< 0.001|
| Married/de facto||97 (64%)||328 (64%)|
| Single/divorced/widowed||55 (36%)||183 (36%)|| 0.99|
| Secondary or less||117 (77%)||72 (14%)|
| Tertiary||35 (23%)||438 (86%)|| < 0.001|
| Religious‡||127 (84%)||401 (79%)|
| Not religious||25 (16%)||109 (21%)|| 0.18|
| Australian/British||144 (95%)||463 (91%)|
| Other||7 (5%)||45 (9%)|| 0.09|
|Self-reported health status|
| Good||68 (45%)||493 (97%)|
| Fair/poor/very poor||84 (55%)||17 (3%)||< 0.001|
|CI = confidence interval. * Median split. †Data were missing for some respondents. ‡Any belief system: Christian, Jewish, Islamic, Hindu or Buddhist.
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2: Percentages of 153 patients and 511 health professionals who replied correctly to questions about cardiopulmonary resuscitation (CPR) before provision of written information|
|% Correct (95% confidence interval)|
|Question||Correct response||Patients||Healthcare professionals|
|What is involved in CPR?|
|Chest compression (external cardiac massage)||Yes*||84% (77%-90%)||100%|
|Kidney machine (dialysis)||No||62% (54%-70%)||99% (98%-100%)|
|Intravenous drugs||Yes*||25% (18%-33%)||84% (80%-87%)|
|Mouth-to-mouth (artificial respiration)|| Yes||86% (80%-91%)||99% (98%-100%)|
|Feeding tube into the nose (nasogastric tube)||No||48% (40%-56%)||96% (94%-98%)|
|Antibiotics||No||56% (48%-64%)||98% (93%-97%)|
|Tube into the throat to assist breathing (intubation)||Yes*||35% (27%-43%)||85% (82%-88%)|
|External electric shock to the heart (defibrillation)||Yes*||60% (51%-68%)||91% (88%-93%)|
|Surgery||No||48% (40%-56%)||98% (96%-99%)|
|Breathing machine (ventilator)||No||27% (20%-35%)||57% (53%-61%)|
|How successful is CPR?|
|All patients||5%-30%||1% (0-4%)||26% (22%-30%)|
|Nursing home patients||< 5%||8% (4%-13%)||62% (58%-66%)|
|Patients who have had recent heart attack||31%-60%||40% (32%-48%)||40% (36%-44%)|
|Patients with widespread cancer||< 5%||42% (34%-50%)||61% (57%-65%)|
|Patients with severe infections (eg, pneumonia)||< 5%||17% (11%-24%)||28% (24%-32%)|
|Patients with kidney failure||< 5%||25% (18%-33%)|| 39% (35%-43%)|
|Patients under 60 years||5%-30%||5% (2%-10%)||22% (18%-26%)|
|Patients over 70 years||5%-30%||15% (10%-22%)||34% (30%-38%)|
|* As these answers are contentious, analyses were performed using both responses. |
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