Impact of written information on knowledge and preferences for cardiopulmonary resuscitation

Ian H Kerridge, Sallie-Anne Pearson, Isobel E Rolfe, Michael Lowe and John R McPhee
Med J Aust 1999; 171 (5): 239-242.
Published online: 6 September 1999

Impact of written information on knowledge and preferences for cardiopulmonary resuscitation

Ian H Kerridge, Sallie-Anne Pearson, Isobel E Rolfe, Michael Lowe and John R McPhee

MJA 1999; 171: 239-242

Abstract - Introduction - Methods - Results - Discussion - Acknowledgements - References - Authors' details
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Abstract Aim: To investigate knowledge about and attitudes to cardiopulmonary resuscitation (CPR), and to determine whether written information about CPR alters knowledge and choices made.
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.

Introduction 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 300%.7

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 about CPR.8

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.

Questionnaire The questionnaire asked about:

  • sociodemographic characteristics;

  • 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 and choices.

Statistical analyses
Data were analysed with SPSS version 6.0 for Windows.9 Sociodemographic characteristics of patients and health professionals were compared using continuity-corrected χ2 analyses. All other analyses were performed for patients and health professionals separately.

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.

Ethical approval
The study was approved by the Hunter Area Health Service Research Ethics Committee and the University of Newcastle Human Research Ethics Committee.


Subjects 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 [110], incompetence as assessed by MMSE [35], visual or language problems [24], psychiatric illness [9], or as they were undergoing procedures [5]); 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% CI, 13.7-14.2).

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% CI, 3.3-3.7).

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.

Discussion 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 for CPR.

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 preferences.

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 preferences.

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 law.21

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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  3. Rabkin MT, Gillerman JD, Rice NR. Orders not to resuscitate. N Engl J Med 1976; 295: 364-366.
  4. Decisions relating to cardiopulmonary resuscitation. A statement from the British Medical Association and the Royal College of Nursing in association with the Resuscitation Council (UK). London: BMA, 1993.
  5. Miller DL, Jahnigen DW, Gorbien MJ, Simbarti L. Cardiopulmonary resuscitation: how useful? Attitudes and knowledge of an elderly population. Arch Intern Med 1992; 152: 578-582.
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  19. Rogers v Whitaker (1992) 175 CLR 479.
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(Received 13 Jan, accepted 7 Jul, 1999)

Authors' details Faculty of Medicine and Health Sciences, University of Newcastle, Newcastle, NSW.
Ian H Kerridge, MPhil, Lecturer in Clinical Ethics;
Sallie-Anne Pearson, PhD, Research Academic;
Isobel E 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
(n =153)
Healthcare professionals
(n =511)

Age > 35 years*90 (59%)235 (46%) 0.007
Female98 (65%)373 (73%)< 0.001
Marital status
 Married/de facto97 (64%)328 (64%)
 Single/divorced/widowed55 (36%)183 (36%) 0.99
 Secondary or less117 (77%)72 (14%)
 Tertiary35 (23%)438 (86%) < 0.001
 Religious127 (84%)401 (79%)
 Not religious25 (16%)109 (21%) 0.18
Ethnic background
 Australian/British144 (95%)463 (91%)
 Other7 (5%)45 (9%) 0.09
Self-reported health status
 Good68 (45%)493 (97%)
 Fair/poor/very poor84 (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)
QuestionCorrect responsePatientsHealthcare professionals

What is involved in CPR?
Chest compression (external cardiac massage)Yes*84% (77%-90%)100%
Kidney machine (dialysis)No62% (54%-70%)99% (98%-100%)
Intravenous drugsYes*25% (18%-33%)84% (80%-87%)
Mouth-to-mouth (artificial respiration) Yes86% (80%-91%)99% (98%-100%)
Feeding tube into the nose (nasogastric tube)No48% (40%-56%)96% (94%-98%)
AntibioticsNo56% (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%)
SurgeryNo48% (40%-56%)98% (96%-99%)
Breathing machine (ventilator)No27% (20%-35%)57% (53%-61%)
How successful is CPR?
All patients5%-30%1% (0-4%)26% (22%-30%)
Nursing home patients< 5%8% (4%-13%)62% (58%-66%)
Patients who have had recent heart attack31%-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 years5%-30%5% (2%-10%)22% (18%-26%)
Patients over 70 years5%-30%15% (10%-22%)34% (30%-38%)

* As these answers are contentious, analyses were performed using both responses.
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Received 21 September 2018, accepted 21 September 2018

  • Ian H Kerridge
  • Sallie-Anne Pearson
  • Isobel E Rolfe
  • Michael Lowe
  • John R McPhee



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