Volume 171 Issue 5

Research Outcomes after hip or knee replacement surgery for osteoarthritis A prospective cohort study comparing patients' quality of life before and after surgery with age-related population norms Lyn M March, Marita J Cross, Helen Lapsley, Alan J M Brnabic Katherine L Tribe, Clarissa J M Bachmeier, Brett G Courtenay and Peter M Brooks* MJA 1999; 171: 235-238 For editorial comment, see Williamson Abstract - Introduction - Methods - Results - Discussion - Acknowledgements - References - Authors' details - - More articles on Orthopaedic surgery Abstract Objective: To compare the health-related quality of life of people with osteoarthritis before and after primary total hip and knee replacement surgery with that of the general Australian population. Design: A prospective cohort study. Setting: Three Sydney hospitals, public and private. Participants: Patients with osteoarthritis undergoing primary total hip (n = 59) and knee (n = 92) joint replacement surgery. Main outcome measure: Medical Outcomes Study Short Form (SF-36) scores before and 12 months after joint replacement surgery (compared with population norms). Results: Patients in each age group showed a significant improvement in health-related quality of life after joint replacement surgery in most scales of the SF-36, particularly physical function, role physical and bodily pain. SF-36 scores for the 42 hip-replacement patients aged 55-74 years improved to equal or exceed the population norm on all scales. SF-36 scores of the 52 knee replacement patients aged 55-74 years improved, but physical function and bodily pain scores remained significantly worse than the population norm. SF-36 scores for both hip (n = 17) and knee (n = 40) replacement patients aged 75 years and over improved significantly, becoming similar to population norms for this age group. Conclusions: Total hip or knee replacement for osteoarthritis significantly improves patient health and well-being at 12 months after surgery. Age alone should not be a barrier to surgery. Introduction Osteoarthritis is one of the leading causes of pain and disability in the Australian population.1,2 Total joint replacement is the most common treatment for advanced osteoarthritis of the hip or knee, with the primary goal of the procedure being to improve the patient's quality of life.3In Australia, in the financial year 1997/98, Medicare benefits of $13 500 000 were paid for 17 000 hip and knee replacements. This number represents only some of the total surgery performed, as the number of operations on Veterans' Affairs patients and on public patients in public hospitals are not available. Despite joint replacement surgery being one of the most common operations performed in this country, very limited Australian outcomes data have been published.4 The Medical Outcomes Study Short-Form 36 (SF-36) has been used extensively to assess the effect on quality of life of several procedures, including total joint replacement,5,6 and it has been suggested that it should be the focus of preoperative and postoperative outcome evaluation for total hip arthroplasty.7 As a generic measure of health-related quality of life with standardised scoring, it enables comparisons between diseases, treatments and published population norms. It measures health on eight 100-point scales: physical function, role physical (ie, role limitations due to physical problems), bodily pain, general health, vitality, social function, role emotional (ie, role limitations due to emotional problems), and mental health. It is one of the most widely used health-related quality-of-life instruments and has been shown to be reliable and valid. Studies in the US have shown that the SF-36 detects a significant improvement in health-related quality of life in patients undergoing total hip or knee replacement when preoperative scores are compared with postoperative scores.8-11 The SF-36 also demonstrates a difference in outcome between total hip and total knee replacement patients,8,10 with patients undergoing total hip replacement achieving significantly better outcomes than the knee replacement patients. We aimed to compare the health-related quality of life (as measured by the SF-36) of people with osteoarthritis undergoing primary total hip and knee replacement surgery with that of the normal Australian population.2 Putting changes in the health-related quality of life of these patients in the context of population norms for the same age group gives us a meaningful measure of the effectiveness of this surgery. It also provides information in a way that allows comparisons with other diseases and treatments, assisting rational choices to be made about the use of the limited healthcare dollar. Methods The information on the patients undergoing total joint replacement collected for this analysis was part of a long-term follow-up of patients in a cohort study aiming to assess the costs of arthritis and the effectiveness of its treatment. The cohort includes patients from both public and private hospitals and surgeons operating in both sectors are involved. Patients with osteoarthritis booked for primary total hip or knee replacement surgery at three Sydney hospitals (St Vincent's public and private hospitals and the Centre for Bone and Joint Diseases, North Ryde) between March 1994 and December 1995 were approached to participate in the study. Recruitment was through regular contact with the orthopaedic surgeons and their practice staff. Baseline information was collected from patients through a series of questionnaires, including the SF-36. Questionnaires were administered between one week and three months before surgery. After surgery, patients completed the SF-36 questionnaire at the end of each three months for their first postoperative year. Most questionnaires were self-administered, with less than 10% requiring face-to-face interview. This is consistent with the Australian Bureau of Statistics methodology for collecting general population data.2 Annual follow-up of these patients by mail is continuing. This article presents SF-36 information from patients at baseline and 12 months after surgery. Ethics committee and Medical Board approval was obtained from the St Vincent's campus of the University of New South Wales Medical School, the Centre for Bone and Joint Diseases and the Royal North Shore Hospital. All patients in the study gave written informed consent. Analysis Mean scores for each of the SF-36 dimensions were calculated for patients in the age groups 55-64, 65-74 and 75 years and over. Scores for men and women were combined, as, apart from older males undergoing joint replacement having lower preoperative scores for role emotional, there was no significant difference in scores between the sexes. Scores for each dimension were transformed according to the SF-36 user's guide12 to a scale of 0-100 (100 = best possible score). We used one-sample t tests to compare the transformed scores with general population norms derived by the Australian Bureau of Statistics from the 1995 National Health Survey. The t test was chosen on the assumption that the population value was the real value (given that published standard errors were so low) and that we were observing the variance of the study data from the population value. A P value of 0.05 was considered to be significant and no adjustment was made for multiple comparisons. SF-36 on the web More information about the SF-36 health survey can be found on the SF-36 website: http://www.sf-36.com An online demonstration of the SF-36 survey (score yourself and read an explanation of the result in comparison with US population norms) is available at: http://www.qmetric.com/demo/sf-36v1.shtml Results Two-thirds of the eligible patients were recruited (226 of 343). Reasons for exclusion included being unable to be contacted before surgery (50% of those who did not participate in the study), being non-English-speaking (10%) and refusal or inability to complete the questionnaires (40%). Eligible patients who did not participate in the study did not differ significantly from the cohort in terms of age, sex or type of joint replacement (ie, hip or knee) (data not shown). At the time of analysis, we had complete information for 151 patients at 12 months' follow-up (59 with hip replacement and 92 knee replacement; 52% female; median age, 72 years). An additional 75 patients (60% female; median age, 74 years) had incomplete follow-up information. Their last recorded SF-36 scores showed no significant differences from scores at the same stage of follow-up among those with complete information (data not shown). Patients' SF-36 scores before and 12 months after surgery are shown in the Figure, in comparison with scores for the general population. Knee replacements 55-64 years age group: Eight patients undergoing knee replacement were recruited. Six of these patients reported having other illnesses, most commonly cardiovascular disease (reported by five patients). At 12 months' follow-up, these eight patients showed improvement from baseline according to mean SF-36 scores for physical function, role physical, bodily pain and vitality, but these scores remained significantly lower than the population norms. The power to detect the observed difference to be statistically significant at the 5% level ranged from 83% to 100% for these four comparisons. Their scores on the other four scales (general health, social function, role emotional, mental health) remained lower than population norms, but this difference was not statistically significant (power to detect a significant difference ranged from 7% to 55%). 65-74 years age group: Twenty-eight of the 44 patients (64%) reported having a comorbid illness, with the most commonly reported again being cardiovascular disease (61% of those with comorbidity). Mean SF-36 scores improved significantly on all scales except general health. The mean general health score was significantly higher than the population norm at 12 months' follow-up, but had been higher to begin with at baseline. Mean physical function, role physical and bodily pain scores remained significantly lower than the population norms at 12 months' follow-up. The power to detect these differences ranged from 85% to 99%. Mean vitality, social function, role emotional and mental health scores improved from baseline to be similar to population norms. The power to detect the significance of these differences ranged from 8% to 36%. 75 years and over: Thirty-two of the 40 patients (80%) reported suffering from another illness, most commonly cardiovascular disease (60% of those with comorbidities). Mean SF-36 scores improved significantly on most scales (particularly role physical, physical function and bodily pain), but not on general health and mental health, which were fairly high before surgery. The mean general health score was significantly higher than the population norm at 12 months' follow-up; the other scores improved to population levels. Given the small difference seen between patient and population scores, large numbers would be required to show statistically significant differences (power ranged from 7% to 33%). Hip replacements 55-64 years age group: Comorbidities were reported by 5 of the 14 patients (36%). All five had cardiovascular disease among other comorbidities. Mean scores for vitality and social function improved to become significantly higher than the population norms (power to detect significant difference, 90% and 96%, respectively), while the other scores improved to be similar to the population norms, with particular improvement in physical function, role physical and bodily pain. 65-74 years age group: Thirteen of the 28 patients reported suffering from a comorbid illness, most commonly cardiovascular disease (46% of patients with comorbidities). Mean SF-36 scores improved on all scales except general health, which had a baseline value above the population norm. Mean scores for general health and mental health were significantly higher than the population norms at 12 months' follow-up (power to detect difference, 85% and 75%, respectively) and the other scores improved to be similar to the population norms (power to detect difference ranged from 7% to 58%). The improvement from baseline was particularly evident in role physical, physical function and bodily pain scores. 75 years and over: Comorbidities were reported by 12 of the 17 patients (71%), most commonly cardiovascular disease (reported by 58% of those with comorbidities). Mean SF-36 scores improved on all scales except general health and mental health. At 12 months' follow-up, mean scores on none of the scales were significantly different from the population norms, possibly due to the small numbers in this group (power to detect a difference less than 30% for most scales). Again, there was improvement to population norms in role physical, physical function and bodily pain. Discussion We found that knee or hip replacement surgery significantly improved the health-related quality of life of patients with osteoarthritis. Before surgery, the patients had poor SF-36 scores for bodily pain, physical function and role physical, a clear reflection of the impact of chronic osteoarthritis on health-related quality of life. After surgery, the biggest improvements were in these scores. Improvement in these physical dimensions of health is likely to lead to improvements in social function, mental health and vitality. We found no improvement in general health despite gains in the other scales. This has been shown in other studies,11 and has been suggested to be due to the patients' previous medical history and pre-existing and general health-related conditions. In our study it was apparent that the general health of patients was already higher at baseline than the population norm, suggesting that relatively healthy patients are being selected for total joint replacement. A US study that compared patients undergoing total hip replacement with age-matched and sex-matched population norms found that age and sex made important differences in SF-36 scores.9 Men younger than 65 years had scores lower than the norms in the physical scales, but were comparable in the mental scales, and women scored lower than the norm in all scales. No sex differences were found in our study, but similar age differences were observed, particularly for patients undergoing total knee replacement, among whom the youngest age group had the poorest outcome relative to the age-matched population. We hypothesise that this may be related to the higher population norms for this age group, unrealistic expectations for outcomes among patients, and the presence of existing comorbidities in younger patients requiring knee replacement. One implication of these findings is that older age should not be a barrier to joint replacement surgery, as the outcome is likely to be relatively successful for older patients. Potential limitations that need to be considered when interpreting these results include the non-randomised cohort design, the power of the analysis given the small sample size of the subgroups, and the overall response rate. However, the inclusion of several groups of surgeons operating at different sites and across the public and private sectors contributed significantly to the generalisability of the results. This study showed the improvement of SF-36 scores of patients undergoing total hip or knee replacement up to and in some cases beyond population norms. Whether these statistically significant differences are clinically important remains to be seen. Longer follow-up is required to determine whether the dramatic improvement from baseline is maintained. Nonetheless, at one year follow-up, it would appear that total knee or hip joint replacements are successful at restoring health and well-being, and that older age alone should not be a barrier to surgery. Acknowledgements This study was funded by grants from the National Health and Medical Research Council. We are grateful to the secretarial staff of the orthopaedic surgeons for their assistance with recruitment to this study and to the patients who have been so cooperative. References Australian Bureau of Statistics. Disability and handicap, Australia 1988. Canberra: ABS, 1996 (Catalogue No. 4120.0). Australian Bureau of Statistics National Health Survey: SF-36 population norms, Australia, 1995. Canberra: ABS, 1997 (Catalogue No. 4399.0). Bombardier C, Melfi CA, Paul J, et al. Comparison of a generic and a disease-specific measure of pain and physical function after knee replacement surgery. Med Care 1995; 33 Suppl 4: AS131-AS144. Van Essen GJ, Chipchase LS, O'Connor D, Krishnan J. Primary total knee replacement: short-term outcomes in an Australian population. J Quality Clin Practice 1998; 18: 135-142. Bayley KB, London MR, Grunkemeier GL, Lansky DJ, Measuring the success of treatment in patient terms. Med Care 1995; 33 Suppl 4: AS226-AS235. Stucki G, Liang MH, Phillips C, Katz JN. The Short-Form 36 is preferable to the SIP as a generic health status measure in patients undergoing elective total hip arthroplasty. Arthritis Care Res 1995; 8: 174-181. Ritter MA, Albohm MJ, Overview: maintaining outcomes for total hip arthroplasty. The past, present and future. Clin Orthop 1997; 344: 81-87. Hozack J, Rothman RH, Albert TJ, et al. Relationship of total hip arthroplasty outcomes to other orthopaedic procedures. Clinical Orthop 1997; 344: 88-93. Lieberman JR, Dorey F, Shekelle P, et al. Outcome after total hip arthroplasty. Comparison of a traditional disease-specific and a quality of life measurement of outcome. J Arthroplasty 1997; 12: 639-645. Kiebzak GM, Vain PA, Gregory AM, et al. SF-36 general health status survey to determine patient satisfaction at short-term follow-up after total hip and knee arthroplasty. J Southern Orthop Assoc 1997; 6: 169-172. Ritter MA, Albohm MJ, Keating EM, et al. Comparative outcomes of total joint arthroplasty. J Arthroplasty 1995; 10: 737-741. Medical Outcomes Trust. How to score the SF-36 health survey. Boston: The Trust, 1994. (Received 16 Oct 1998, accepted 12 Jun 1999) Authors' details University of Sydney, Department of Rheumatology, Royal North Shore Hospital, Sydney, NSW. Lyn M March, MB BS, PhD, FRACP, FAFPHM, Associate Professor. Department of Medicine, University of New South Wales, Sydney, NSW. Marita J Cross, BSc(Hons), Research Assistant; Katherine L Tribe, BSc(Hons), Research Assistant; Clarissa J M Bachmeier, MD, MMed(ClinEpidem), Research Fellow. School of Health Services Management, University of New South Wales. Helen Lapsley, BA, MEc, Senior Lecturer. Northern Sydney Public Health Unit, Hornsby Ku-ring-gai Hospital, Sydney, NSW. Alan J M Brnabic, MSc, Statistician. Department of Orthopaedics, St Vincent's Hospital, Sydney, NSW. Brett G Courtenay, MB BS, FRACS, Orthopaedic Surgeon. Faculty of Health Sciences, University of Queensland, Brisbane, Qld. Peter M Brooks, MB BS, FRACP, FAFPHM, Executive Dean. No reprints will be available from the authors. Correspondence: Associate Professor L M March, Department of Rheumatology, Royal North Shore Hospital, St Leonards, NSW 2065. Email: lmarcATdoh.health.nsw.gov.au Click in figure for a larger version Back to text

Lyn M March · Marita J Cross · Helen Lapsley · Katherine L Tribe · Brett G Courtenay · Peter M Brooks

Research 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 - - More articles on Ethics 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 Methods 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. Results 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. Acknowledgements We would like to thank the interviewers and patients and staff of the John Hunter Hospital for their generous participation in this study. References Robinson GR, Hess D. Post-discharge survival and functional status following in-hospital cardiopulmonary resuscitation. Chest 1994; 105: 991-994. Landry FJ, Parker JM, Phillips YY. Outcome of cardiopulmonary resuscitation in the intensive care setting. Arch Intern Med 1992; 152: 2305-2308. Rabkin MT, Gillerman JD, Rice NR. Orders not to resuscitate. N Engl J Med 1976; 295: 364-366. 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. 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. Schonwefter RS, Walker RM, Kramer DR, Robinson BE. Resuscitation decision-making in the elderly: the value of outcome data. J Gen Intern Med 1993; 8: 295-300. Potter JM, Stewart D, Duncan G. Living wills: would sick people change their minds? Postgrad Med J 1994; 70: 818-820. Kerridge IH, Pearson SA, Rolfe IE, Lowe M. Decision making in CPR: attitudes of hospital patients and health care professionals. Med J Aust 1998; 169: 128-131. SPSS. Statistical package for the social sciences. Version 6.0 for Windows. Chicago, Ill: SPSS Inc, 1990. Schmerling RH, Bedell SE, Lilienfeld A, Delbanco TL. Discussing cardiopulmonary resuscitation: a study of elderly outpatients. J Gen lntern Med 1988; 3: 317-321. Murphy DJ, Burrows MD, Santilli S, et al. The influence of the probability of survival on patients' preferences regarding cardiopulmonary resuscitation. N Engl J Med 1994; 330: 545-549. Schonwetter RS, Teasdale TA, Taffet G, et al. Educating the elderly: cardiopulmonary resuscitation decisions before and after intervention. J Am Geriatr Soc 1991; 39: 372-377. Frankl D, Oye RK, Bellamy PE. Attitudes of hospitalised patients toward life support: a survey of 200 medical inpatients. Am J Med 1989; 6: 645-648. Ebell MH, Doukas DJ, Smith MA. The do-not-resuscitate order: a comparison of physician and patient preferences and decision-making. Am J Med 1991; 91: 255-260. Robertson GS. Resuscitation and senility: a study of patients' opinions. J Med Ethics 1993; 19: 104-107. Bedell SE, Delbanco TL, Cook EF, Epstein FH. Survival after cardiopulmonary resuscitation. Crit Care Med 1983; 309: 569-576. Miller DL, Gorbien MJ, Simbarti LA, Jahnigen DW. Factors influencing physicians in recommending in-hospital cardiopulmonary resuscitation. Arch Intern Med 1993; 153: 1999-2003. Wagg A, Kinirons M, Stewart K. Cardiopulmonary resuscitation: doctors and nurses expect too much. J R Coll Physicians Lond 1995; 29: 20-24. Rogers v Whitaker (1992) 175 CLR 479. Chappel v Hart [1998] HCA 55. Wyong Shire Council v Shirf (1980) 146 CLR 40. (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. Email: ikerridgATmail.newcastle.edu.au 1: Sociodemographic characteristics of patients and health professionals surveyed about cardiopulmonary resuscitationPatients (n =153)Healthcare professionals (n =511)PAge > 35 years*90 (59%)235 (46%) 0.007Female98 (65%)373 (73%)< 0.001Marital status† Married/de facto97 (64%)328 (64%) Single/divorced/widowed55 (36%)183 (36%) 0.99Education† Secondary or less117 (77%)72 (14%) Tertiary35 (23%)438 (86%) < 0.001Religion† Religious‡127 (84%)401 (79%) Not religious25 (16%)109 (21%) 0.18Ethnic background† Australian/British144 (95%)463 (91%) Other7 (5%)45 (9%) 0.09Self-reported health status Good68 (45%)493 (97%) Fair/poor/very poor84 (55%)17 (3%)< 0.001CI = confidence interval. * Median split. †Data were missing for some respondents. ‡Any belief system: Christian, Jewish, Islamic, Hindu or Buddhist. Back to text 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 professionalsWhat 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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Ian H Kerridge · Sallie-Anne Pearson · Isobel E Rolfe · Michael Lowe · John R McPhee

Notable Cases Poisoning by Amanita phalloides ("deathcap") mushrooms in the Australian Capital Territory Amanita phalloides ("deathcap") mushrooms are widespread in south-eastern Australia. Seven patients presented to hospital in the Australian Capital Territory with poisoning by this mushroom between 1988 and 1998. Three developed hepatoxicity and one died. Because A. phalloides is becoming more widespread, increased community and medical awareness is needed to reduce the frequency and morbidity of poisoning. Amanita phalloides mushrooms growing under an oak tree on the western shores of Lake Burley Griffin, Canberra. MJA 1999; 171: 247-249 Geoffrey M Trim, Heino Lepp, Matthew J Hall, Robin V McKeown, Geoffrey W McCaughan, Geoffrey G Duggin and David G Le Couteur Introduction - Clinical records - Discussion - Acknowledgements - References - Authors' details - - More articles on Toxicology Introduction The "deathcap" mushroom, Amanita phalloides, accounts for most deaths after mushroom ingestion.1,2 There are four clinical phases of poisoning: an initial asymptomatic latent phase, a gastrointestinal phase characterised by watery diarrhoea, a honeymoon period when symptoms temporarily resolve, and a final hepatic phase characterised by hepatic and renal failure. In an adult, death may ensue within 7-10 days of ingestion of a single cap.1,2 We report seven cases of poisoning by A. phalloides mushrooms that occurred in the Australian Capital Territory (ACT) between 1988 and 1998. The only other Australian reports have been from Victoria,3,4 and there is now concern that the mushroom may be becoming more widespread in Australia. Clinical records The seven cases are summarised in the Box. Patients comprised six adults aged 20-46 years and a seven-year-old child. All patients had eaten cooked mushrooms that they had picked in gardens or streets of Canberra, except the child, who had eaten part of a raw mushroom she had picked in her schoolyard. Three Laotians were poisoned at the same time when they mistook A. phalloides for the superficially similar-appearing paddy straw mushroom (Volvariella volvacea), common in South-East Asia. The dose ranged from a quarter to eight mushrooms. All patients presented after one to two days with diarrhoea and, in most cases, vomiting, except the child, who vomited within two hours and was brought for medical attention immediately. The diagnosis was made on initial presentation in only this child and the other 1998 patient (Patient 2). Three patients developed significant hepatic dysfunction, and two were transferred to a liver transplant unit, one of whom died. Details of the two who were transferred follow. Patient 1 In 1995, a 46-year-old man ate eight mushrooms which he had picked in a north Canberra suburb. He presented with vomiting and diarrhoea the next day, but, as he was confident that the mushrooms were not A. phalloides, he was discharged home after receiving intravenous rehydration. He presented again two days later with hepatic and renal failure. Initial investigations revealed the following serum levels: alanine aminotransferase (ALT) > 10 000 U/L (reference range [RR], 5-55 U/L); bilirubin, 114 µmol/L (RR, 3-20 µmol/L); creatinine, 535 µmol/L (RR, 40-90 µmol/L); and prothrombin time - international normalised ratio (PT-INR) > 10. A mycologist identified A. phalloides growing in the street where the patient had picked the mushrooms and also identified the mushroom stalks that he had discarded in a rubbish bin. The patient was transferred to a liver transplant unit but died from hepatic failure six days after mushroom ingestion. Postmortem examination of his liver revealed complete necrosis of parenchyma, with one residual island of intensely vacuolated hepatocytes with severe intracanalicular biliary stasis. No viable hepatocytes were seen. Patient 2 In 1998, a 39-year-old man ate three mushrooms picked from his back garden in an inner Canberra suburb. The mushrooms were cooked as a pasta sauce. He had been previously well but had been taking griseofulvin for six months to treat a fungal toenail infection. Eighteen hours after ingestion, he developed watery diarrhoea. He presented to hospital with dehydration and epigastric discomfort 36 hours after ingestion. Initial investigations revealed the following serum levels: ALT, 914 U/L; bilirubin, 24 µmol/L; and creatinine, 102 µmol/L. He had evidence of metabolic acidosis, with pH of 7.30 (RR, 7.34-7.44) and bicarbonate level of 18.6 mmol/L (RR, 22-26 mmol/L). The mushrooms were identified as A. phalloides by a mycologist. The patient was transferred to a liver transplant unit and treated with intravenous fluids, high dose penicillin and N-acetylcysteine. Three days after mushroom ingestion, his serum ALT level peaked at 8199 U/L, and PT-INR at 4.7, but he did not develop encephalopathy. He subsequently made an uneventful recovery. Discussion Our seven patients poisoned by A. phalloides mushrooms in the ACT is the only series reported in Australia. In five of our seven patients, the diagnosis was not made on initial presentation, and in one it was not suspected at all, despite a history of mushroom ingestion and characteristic clinical picture. Three patients developed significant hepatic dysfunction, two were transferred to a liver transplant unit and one died. There have been only two other reports of poisoning by A. phalloides mushrooms in Australia,3,4 both in Victoria. Neither case was diagnosed on initial presentation, and one was fatal.3A. phalloides is a mycorrhizal fungus (ie, it grows in a symbiotic association with the roots of trees, primarily oak trees). It produces a range of toxins (amatoxins). The major toxin, a cyclic peptide, amanitin, inhibits RNA polymerase II and is not inactivated by cooking, freezing or drying. The lethal dose is about 0.1 mg/kg, which may be contained in as little as one mushroom.5 Amanitin is usually cleared rapidly, mainly by renal excretion.6 Recommended treatment of A. phalloides poisoning includes vigorous gastrointestinal decontamination.7 Early and aggressive decontamination may have prevented toxicity in the seven-year-old child. Supportive care, including intravenous rehydration, is thought responsible for most of the improvement in mortality, from well over 50% early this century to 20%-30% in recent decades.1 Many specific antidotes have been used, although no prospective-trial evidence is available. Retrospective clinical studies and animal studies support the use of high dose penicillin (0.5-1 million units/kg per day) and parenteral silibinin, an extract of milk thistle available only in Europe. Both are thought to act by inhibiting amatoxin uptake into hepatocytes and by interfering with its enterohepatic circulation.1,7 Cimetidine, a hepatic enzyme inhibitor, may be harmful.8 We speculate that, in Patient 1, long-term use of griseofulvin (a hepatic enzyme inducer) before poisoning may have increased the rate of detoxification of amatoxin and thereby contributed to survival. Liver transplantation may be used in cases that fail to respond to more conservative measures. It has been performed successfully for this indication in the United States since 1985,9 but has not been attempted for this indication in Australia. A. phalloides mushrooms have been described in many regions of south-eastern Australia. Collections have been made in several Melbourne suburbs,4,10,11 and the Victorian country centres of Riddells Creek, Morwell and Walhalla.11 The National Herbarium of Victoria and the State Herbarium in Adelaide hold collections of A. phalloides or very similar species from New South Wales, Tasmania and Victoria. A. phalloides mushrooms were first reported in Canberra in 19614 and are now widespread in the ACT. Although A. phalloides is found primarily in association with oak trees, there is concern among mycologists and toxicologists that it may develop the ability to grow in association with other trees, particularly Australian natives, and thereby spread dramatically. Associations between Eucalyptus spp. and Amanita spp. other than A. phalloides have been reported in other countries,12 and between Eucalyptus spp. and A. phalloides itself in Africa.13,14 There is anecdotal evidence of A. phalloides forming mycorrhizae with Eucalyptus spp. in Canberra (Richard Windsor, consultant botanist, Canberra, ACT, personal communication). A. phalloides is not the only mushroom to contain amatoxins. In the northern hemisphere, these toxins are found in other Amanita species and in species within the genera Conocybe, Galerina and Lepiota,1 which also occur in Australia. Four cases of Lepiota helviola poisoning have been reported from Adelaide. In each, hepatotoxicity occurred and amatoxins were identified.4,15 A. phalloides is now widely distributed in south-eastern Australia, and may become more widespread if it develops the ability to grow in association with eucalyptus trees. Increased community and clinician awareness is needed to reduce the incidence of poisoning and to improve outcomes. Wild mushrooms should not be eaten unless definitely identified as non-poisonous. Clinicians should consider A. phalloides poisoning in patients with vomiting, diarrhoea or abnormal liver function. Acknowledgements We thank Graham Bell (State Herbarium, Adelaide) and Tom May (National Herbarium of Victoria) for information about Amanita phalloides collections in their herbaria, and Richard Windsor (Canberra, ACT) for his comments about A. phalloides and Eucalyptus spp. in Canberra. References Benjamin DR. Amatoxin syndrome. Mushrooms: poisons and panaceas -- a handbook for naturalists, mycologists and physicians. New York: W H Freeman and Company, 1995: 198-241. Pond SM, Olson KR, Woo OF, et al. Amatoxin poisoning in northern California, 1982-1983. West J Med 1986; 145: 204-209. Nicholson FB, Korman MG. Death from Amanita poisoning. Aust N Z J Med 1997; 27: 448-449. Southcott RV. Notes on some poisonings and other clinical effects following ingestion of Australian fungi. S Aust Clin 1974; 6: 442-478. Weiland T. Poisonous principles of mushrooms of the genus Amanita. Science 1968; 159: 946-952. Jaeger A, Jehl F, Flesch F, et al. Kinetics of amatoxins in human poisoning: therapeutic implications. J Toxicol Clin Toxicol 1993; 31: 63-80. Floersheim GL. Treatment of human amatoxin mushroom poisoning: myths and advances in therapy. Med Toxicol 1987; 2: 1-9. Schneider SM, Vanscoy G, Michelson EA. Failure of cimetidine to affect phalloidin toxicity. Vet Hum Toxicol 1991; 33: 17-18. Klein AS, Hart J, Brems JJ, et al. Amanita poisoning: treatment and the role of liver transplantation. Am J Med 1989; 86: 187-193. Reid DA. A monograph of the Australian species of Amanita Pers. ex Hook (Fungi). Aust J Bot Supplementary Series No. 8, 1980: 48. Cole FM. Amanita phalloides in Victoria. Med J Aust 1993; 158: 849-850. May TW, Wood AE. Extra-Australian species associated with Eucalyptus. Fungi of Australia. Volume 2A. Canberra: Australian Biological Resources Study and CSIRO, CSIRO, 1997: 239-240. Malencon G, Bertault R. Flore des champignons supérieurs du Maroc. Tome I. Rabat, Morocco: Faculté des Sciences, 1970: 75. Pegler DN. Amanitaceae. A preliminary agaric flora of East Africa. London: HMSO, 1977: 296-297. Lloyd C, White J, Downes S, et al. Amatoxin poisoning following ingestion of Lepiota helviola. Report of two cases with hepatotoxicity. Abstracts of the 10th World Congress on Animal, Plant and Microbial Toxins. Singapore; 1991 3-8 Nov. 1991: 345. (Received 11 Feb, accepted 24 Jun, 1999) Authors' details Canberra Hospital, Canberra, ACT. Geoffrey M Trim, MB BS, Clinical Pharmacology Registrar; Robin V McKeown, PhC, Poisons Information Service; David G Le Couteur, FRACP, PhD, Associate Professor, The Canberra Clinical School of the University of Sydney. Australian National Herbarium, Centre for Plant Biodiversity Research, Canberra, ACT. Heino Lepp, BSc(Hons), Scientific Associate. Royal Prince Alfred Hospital, Sydney, NSW. Matthew J Hall, MB BS, Gastroenterology Registrar; Geoffrey W McCaughan, FRACP, PhD, Physician-in-Charge, Australian National Liver Transplant Unit; Geoffrey G Duggin, FRACP, Head, Toxicology Unit. Reprints will not be available from the authors. Correspondence: Associate Professor D G Le Couteur, Department of Clinical Pharmacology, The Canberra Hospital, Yamba Drive, Garran, ACT 2605. Email: david_lecouteurATdpa.act.gov.au Amanita phalloides mushrooms at different stages of the lifecycle. A mature "deathcap" typically has a greenish-brown to white cap, white gills on the underside of the cap, a white frill-like ring on a white to pale yellow-green stem, and a white underground cup. The deathcap may be mistaken by those unfamiliar with fungi for mushrooms of the genus Agaricus, the type most commonly grown for consumption. The deathcap also superficially resembles the edible paddy straw mushroom (Volvariella volvacea). Seven cases of poisoning by Amanita phalloides in the Australian Capital Territory, 1988-1998 YearAge (years) sexMushrooms ingested (identified*)SymptomsResults of liver function testsTreatmentOutcome 198820, M† Several (yes)Diarrhoea after 1-2 daysNormalNilRecovered 20, M† Several (yes)Diarrhoea after 1-2 daysNormalNilRecovered 20, F† Several (yes)Diarrhoea, vomiting after 1-2 daysNormal Intravenous fluidsRecovered 199546, M‡8 (yes)Diarrhoea, vomiting after 1-2 daysALT > 10 000 U/L; PT-INR > 10; creatinine 535 µmol/LTransferred to transplant unit, intravenous fluids, high dose penicillin, N-acetylcysteineDied 199745, MSeveral (no)Diarrhoea, vomiting after 2 daysALT, 2938 U/L; PT, 19 s; creatinine, 216 µmol/LIntravenous fluidsRecovered 199839, M§3 (yes)Vomiting, diarrhoea after 1-2 daysALT, 8199 U/L; PT-INR, 4.7Transferred to transplant unit, intravenous fluids, high dose penicillin, N-acetylcysteineRecovered 7, F1/4 (yes)Vomiting within 2 hoursNormalIntravenous fluids, whole bowel irrigation, multiple dose activated charcoal, high dose penicillinRecovered ALT = serum alanine aminotransferase level (reference range [RR], 5-55 U/L). PT-INR = prothrombin time, international normalised ratio. PT = prothrombin time (RR, 8-14 s). Creatinine = serum creatinine level (RR, 40-90 µmol/L). * Identity confirmed by a mycologist. † These three people from Laos were poisoned at the same time when they ate mushrooms picked from a Canberra street. ‡ Patient 1. § Patient 2.

Geoffrey M Trim · Heino Lepp · Matthew J Hall · Robin V McKeown · Geoffrey W McCaughan · Geoffrey G Duggin · David G Le Couteur