Volume 167 Issue 2

Burden and outcomes of hospitalisation for congestive heart failure Fiona M Blyth, Ross Lazarus, David Ross, Michael Price, Gary Cheuk and Stephen R Leeder For editorial comment see Krum Readers may print a single copy for personal use. No further reproduction or distribution of the articles should proceed without the permission of the publisher. For permission, contact the Australasian Medical Publishing Company Journalists are welcome to write news stories based on what they read here, but should acknowledge their source as "an article published on the Internet by The Medical Journal of Australia <http://www.mja.com.au/>". Abstract - Introduction - Methods - Results - Discussion - Acknowledgements - References - Authors' details - ©MJA1997 Abstract Objective: To describe the hospital burden and health outcomes associated with admission for congestive heart failure (CHF). Design and setting: Descriptive follow-up study in a tertiary-level metropolitan teaching hospital. Patients: Acute adult inpatients with a clinical diagnosis of CHF for more than 24 hours admitted to Westmead Hospital, Sydney, during the four months from September 1993 to January 1994. At baseline, 122 patients were assessed; 88 patients were assessed at four-month follow-up. Interventions: Usual clinical care. Main outcome measures: Length of stay; hospital bed-days; readmissions; mortality; health related quality of life (SF-36); patient knowledge. Results: The average age of subjects was 73.4 years. Many were using informal domiciliary care before admission. Mean length of stay for the baseline admission was 13.8 days, accounting for 7.6% of hospital separations and 1683 hospital bed-days, or 4.2% of bed-days for all inpatients aged 65 years and over. Fifteen patients were readmitted for CHF during the following four months, with a total of 26 CHF-related admissions. Twenty-one patients (17.2%) died during the course of the study. Quality of life at baseline was poor compared with population normative data, with a slight improvement among survivors at four-month follow-up. Patient knowledge of CHF was poor in a subsample survey ( n = 24). Conclusions: CHF represents a significant burden to patients (through morbidity and mortality), their carers (through provision of daily care), and hospitals (through multiple admissions for acute decompensation). It is difficult to monitor the hospital burden of CHF using routine data sources. MJA 1997; 167: 67-70 Introduction Congestive heart failure (CHF) has been estimated to affect 3%-5% of those aged over 65 years, and 10% of those over 75 years.1 It is the fastest growing cardiovascular disorder in the United States,2 the only one increasing in incidence and prevalence,3 and the leading cause of hospital admission and readmission in Americans aged over 65 years.4 In 1990, CHF cost the US economy $US8 billion, and accounted for five million hospital bed-days.5,6 In Scotland, CHF hospital discharge rates have risen in a decade to be almost equal to those for myocardial infarction.7 In the United Kingdom, the National Health Service spends £360 million per year in diagnosis and management, on a par with spending on stroke or asthma. Most of this expenditure is on hospital admissions.8 As there is little information available on the outcomes of current hospital management of CHF patients,9,10 we describe the health outcomes of a cohort of patients hospitalised with CHF, and the impact of their hospitalisation on a health service. Methods All acute adult patients admitted to Westmead Hospital during four months (September 1993 to January 1994) with a clinical diagnosis of CHF, or who developed CHF of more than 24 hours' duration during an admission, were eligible for inclusion in the study. The diagnosis of CHF was made by medical staff on clinical grounds. Additional eligibility criteria were fluency in English and absence of significant cognitive impairment. Two cardiology-trained research nurses implemented an active daily case-finding strategy to overcome the difficulties encountered in identifying CHF patients from existing record systems. Diagnostic codes are generally not added to the patient's medical record until some time after discharge. Patients were identified by review of the computerised admissions log, medical record chart audit in the relevant ward areas, and consultation with medical staff. Potential subjects were assessed for their general condition and fluency in English and, if appropriate, screened for cognitive impairment by means of the Mini-Mental State examination.11 Informed consent was then sought. If patients were unable to participate fully, consent was sought to review their medical record and follow them up four months later to ascertain vital status. Baseline data were collected by interview, medical record review and self-administered questionnaires. Data were collected on demographic characteristics, domiciliary arrangements, current and past medical history, clinical severity of heart failure (according to the New York Heart Association [NYHA] criteria for grading functional incapacity of patients with cardiac disease), investigations, drug treatment, hospital resource use, formal and informal use of domiciliary care, and health-related quality of life (HRQOL) before admission (measured with the SF-36 [Medical Outcomes Study 36 Item Short Form Health Survey]).12 Patient knowledge about CHF was assessed by a short questionnaire in a subset of 24 consecutive patients. Four months after baseline admission, subjects were contacted by telephone to arrange follow-up by questionnaire. Data were sought on health status, HRQOL, current treatment, and domiciliary arrangements. The hospital's computer system was searched for any readmissions during the follow-up period. All analysis was performed using SAS version 6.08 for Windows.13 Two-sample t tests were used to assess the statistical significance of differences between groups, with adjustments made for multiple comparisons. SF-36 data were scored and subscales were calculated with the recommended scoring algorithm.12 Westmead Hospital Human Research Ethics Committee approved the study, and informed consent was obtained from all participating patients. Results There was no "gold standard" available for checking the accuracy and completeness of study case ascertainment methods. However, a list was assembled of all separations from Westmead Hospital during the study recruitment period with a principal diagnosis code for CHF (ICD-9 codes 428.0, 428.1, 428.9). These were then cross-checked against a list of study subjects. This list identified seven patients who were not identified by study case-finding methods. These were considered "missed" potential cases, but represented a small proportion of this group (4.3%). During the study recruitment period, 154 patients met the required clinical criteria and 122 (79%) consented to participate. Participation and follow-up are detailed in Box 1. Sample characteristics: Women made up 54.9% of the study participants. The mean age was 73.4 years (range, 24-97 years); women were older on average than men (76.8 compared with 69.4 years; P = 0.0001). Most patients had a history of established CHF; 35.2% were undergoing their first hospital admission for CHF. Only 1.8% of patients were NYHA grade I on baseline admission, 12.3% grade II, 64.4% grade III, and 17.5% grade IV (4% lacked data for NYHA classification). Thirty-eight patients had their ejection fraction measured at the baseline admission, with a mean value of 35% (range, 9%-74%). Ischaemic heart disease (58.2%) and hypertension (39.3%) were major aetiological factors in CHF. The cohort was cared for by cardiologists (n = 74; 60.7%), and geriatricians (n = 48; 39.3%). Admission diagnoses are shown in Box 2 (below). When admission diagnoses were compared with ICD-9 codings on the medical record, 39 (86.6%) of the 45 with heart-failure-specific admission diagnoses and 30 (78.9%) of the 38 with suggestive diagnoses had a CHF-related ICD-9 code (428, 428.0, 428.1, 428.9) in one of the first six ICD-9 coding positions. Preadmission characteristics: Data were available for 99 subjects: 88 lived in private accommodation, 50 reported needing regular help from family or friends with general housekeeping, and 23 reported needing help with supervision of medication. Length of stay: The study participants accounted for 7.6% of hospital separations (excluding day-only patients). The mean length of stay during the baseline admission was 13.8 days (SD = 12.1). Length of stay had a markedly skewed distribution (median, 10 days; range, 2-66 days). Overall, the sample accounted for 1683 bed-days during baseline admissions and 10.6% of hospital bed-days associated with the geriatricians and cardiologists who participated in the study. Of those patients aged 65 years and over admitted during the same period, the CHF cohort accounted for 4.2% of bed-days. Readmissions: During the follow-up period, there were 73 readmissions to Westmead Hospital from the study cohort, 26 due to a further episode of CHF in 15 patients. A total of 171 bed-days were used for CHF-related readmissions by the 14 patients for whom data were available. Deaths: Twenty-one patients died during the study (17.2%). Changes in domicile: Eight patients (8.1%) were discharged to a higher level of domiciliary care, suggesting a decline in independence and increased use of health and/or community services. Quality of life: Data on HRQOL before admission were obtained from 84 of the 85 subjects at baseline (Box 3). Mean SF-36 subscale scores for these subjects were generally low, particularly for subscales with physical health components. For each subscale there was a wide range of scores, indicating substantial variability in health-related quality of life before admission. Compared with Australian normative SF-36 data for men and women aged 65 years and over,14 the study cohort reported significantly lower mean HRQOL for all subscales. Follow-up SF-36 data were obtained for 58 subjects (Box 4). Patients with missing follow-up data had either died before follow-up (n = 15) or were too unwell to fill in the form (n = 6). In that sense, the SF-36 results at follow-up represent the "survivor" population within the study cohort. Mean follow-up subscale scores in survivors were somewhat higher compared with their baseline scores. The smallest improvements were in the subscales related to physical health. Improvements in the Social Function, Vitality and Mental Health subscales were statistically significant. Patient knowledge: The 24 patients who completed the questionnaire were similar to the CHF cohort in age, sex, length of stay, and type of treating specialist. Nineteen had been admitted to hospital previously for CHF. Only 11 knew that they had been diagnosed as having heart failure. Although 16 agreed that patients with heart failure would need to take medication permanently, six thought that CHF was unlikely to recur. Nineteen agreed that shortness of breath and 15 agreed that ankle swelling were important symptoms, but only four recognised that rapidly increasing weight was important. Discussion CHF has a significant impact on hospital services. The study cohort contributed significantly to adult bed-days attributable to participating clinicians. A substantial proportion (12.3%) of the cohort was readmitted with CHF within four months of their baseline admission, suggesting an annual readmission rate of around 36%. This compares with an annual readmission rate of nearly 20% in the SOLVD (Studies of Left Ventricular Dysfunction) registry study cohort, who were younger.10 CHF admissions show seasonal variations, with a winter peak that is probably associated with chest infection. Therefore, the impact of CHF on acute hospital services may be even greater at that time of year. The 48 subjects (39.3%) who were admitted under the care of geriatricians were, by hospital admission policy, those aged over 65 with serious comorbidity and/or likely to represent a placement problem after discharge. Many required substantial help with tasks essential for independent living, and most of this help was provided informally. This was clearly a group that would require increased resources with deteriorating health. HRQOL was generally poor in the study participants compared with normative data,14 probably reflecting the combined effects of disease severity and comorbidity. There was limited improvement between baseline and follow-up, particularly in the subscales related to physical health, perhaps indicating that at baseline the lower limits of some SF-36 subscales did not adequately reflect the subjects' condition (i.e., a "floor" effect was operating). The mean changes in scores over time were small, but underlying this was great variability between individuals. At the time of this study there were few educational resources for CHF patients. This is surprising, as CHF is a chronic condition with acute exacerbations that may be ameliorated by early recognition and intervention, and which requires compliance with medication. Some CHF patients may avoid hospital admission by timely intervention prompted by self-monitoring of signs and symptoms. Seventy-six subjects (62.3%) had a recorded history of acute deterioration lasting for more than 24 hours, suggesting a possible opportunity for early recognition and intervention. The patient knowledge survey was limited, but it demonstrated an apparent lack of understanding of key features of CHF. Recent acute illness could have contributed to this. That almost a quarter of the cohort required daily help with taking medications has implications for the targeting of educational interventions. For elderly patients experiencing readmissions for CHF, the risk of dying in the near future and the palliative nature of treatment are additional issues which may need to be explored. This study was constrained, for practical reasons, by reliance on a clinical diagnosis of CHF. In a larger study with more resources, verification of diagnosis and more detailed examination of diagnostic coding practices would be desirable, and would allow identification of subgroups of particular clinical interest. Diagnostic coding practices in routine record keeping do not facilitate monitoring of the public health impact of CHF. A hospital admission for CHF may be assigned a principal ICD-9 code which reflects the underlying cause of CHF, and secondary ICD-9 codes are sometimes used to identify a past medical history of CHF rather than a feature of the current admission. In this study, poor health represented a further barrier to study participation and monitoring outcomes. Most losses to follow-up resulted from death or worsening health. During the study 21 subjects (17.2%) died. This represents a poor survival rate, worse than for many malignancies of adulthood. Cause of death was not ascertained, but in the SOLVD registry cohort10 most deaths were due to progressive CHF. In addition, sudden death occurs in CHF patients at five times the rate in the general population of the same age.15 Chronic CHF represents a significant burden to patients (through morbidity and mortality), their carers (through provision of daily care), and the hospital system (through multiple admissions for acute decompensation). Acknowledgements We acknowledge the contribution of Moira Hewitt, RN, and Jeanette Bunn, RN, to the Westmead CHF Outcomes study, and study coinvestigator Dr Julia Lowe from the Newcastle Heart Failure Group. This study was funded by the NSW Health Department's Health Outcomes Program. References Failure to treat heart failure [editorial]. Lancet 1992; 330: 278-279. Mortality from congestive heart failure --United States, 1980-1990. MMWR Morb Mortal Wkly Rep 1994; 43: 77-81. Yamani M, Massie BM. Congestive heart failure: insights from epidemiology, implications for treatment. Mayo Clin Proc 1993; 68: 1214-1218. Gooding J, Jette AM. Hospital readmissions among the elderly. J Am Geriatr Soc 1985; 33: 595-601. National Centre for Health Statistics, Graves EJ. National Hospital Discharge Survey: Annual Summary, 1990. Vital Health Stat [13] 1992; 112: 28. Munoz E, Chalfin D, Birnbaum E, et al. Hospital costs, resource characteristics, and the dynamics of death for patients with a primary diagnosis of congestive heart failure. N Y State J Med 1989; 89: 60-63. McMurray J. Trends in hospitalisation for heart failure in Scotland 1980-1990. Eur Heart J 1993; 14: 1158-1162. McMurray J, Hart W. The economic impact of hearfailure on the U K National Health Service. Eur Heart J 1993; 14 Suppl: 133. Parameshwar J, Poole-Wilson PA, Sutton GC. Heart failure in a district hospital. J R Coll Physicians Lond 1992; 26: 139-142. Bourassa MG, Gurne O, Bangdiwala SI, et al. for the SOLVD investigators. Natural history and patterns of current practice in heart failure. J Am Coll Cardiol 1993; 22 Suppl A: 14A-19A. Folstein MF, Folstein SE, McHugh PR. "Mini-Mental State": a practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 1975; 12: 189-198. Ware JE, Snow KK, Kosinski M, Gandek B. SF-36 health survey: manual and interpretation guide. Boston: The Health Institute, New England Medical Centre, 1993 . SAS for the Microsoft Windows Environment, Version 6. Cary, NC: SAS Institute Inc, 1993. Stevenson CE. SF-36: Interim norms for Australian data. Canberra: Australian Institute of Health and Welfare, 1996. Kannel WB, Ho K, Thom T. Changing epidemiologic features of cardiac failure. Br Heart J 1994; 72 Suppl: S3-S9. (Received 8 Oct 1996, accepted 10 Apr 1997) Authors' details Westmead Hospital, Sydney, NSW. Fiona M Blyth, FAFPHM, Registrar, Department of Public Health and Community Medicine. Ross Lazarus, FAFPHM, Senior Lecturer in Epidemiology, Department of Public Health and Community Medicine, University of Sydney at Westmead Hospital. David Ross, FRACP, Head, Department of Cardiology. Michael Price, FRACP, Head, Geriatric Medicine Unit. Gary Cheuk, FRACP, Registrar, Geriatric Medicine Unit. Stephen R Leeder, FRACP, PhD, FAFPHM, Professor of Public Health and Community Medicine, University of Sydney at Westmead Hospital. Reprints will not be available from the author. Correspondence: Dr F M Blyth, Department of Public Health and Community Medicine, Westmead Hospital, Westmead, NSW 2145. ©MJA 1997 <URL: http://www.mja.com.au/> © 1997 Medical Journal of Australia.

Fiona M Blyth · Ross Lazarus · David Ross · Michael Price · Gary Cheuk · Stephen R Leeder

Troublesome lower urinary tract symptoms in the community: a prevalence study Carole B Pinnock and Villis R Marshall For editorial comment see Hirst & Ward Readers may print a single copy for personal use. No further reproduction or distribution of the articles should proceed without the permission of the publisher. For permission, contact the Australasian Medical Publishing Company Journalists are welcome to write news stories based on what they read here, but should acknowledge their source as "an article published on the Internet by The Medical Journal of Australia <http://www.mja.com.au/>". Abstract - Introduction - Method - Population surveyed - Survey questionnaire - Results - Discussion - Key points of study - References - Authors' details - ©MJA1997 Abstract Objective: To determine the prevalence of troublesome lower urinary tract symptoms (LUTS) in men and women in the community. Design: Interview-based prevalence survey. Setting: Metropolitan and rural communities in South Australia, September, 1995. Subjects: Probability sample of 1204 men and 1686 women (aged over 18 years) weighted to reflect the age and sex distribution of the South Australian population. Data collected: Presence of storage (irritative) and voiding (obstructive) symptoms, based on the International Prostate Symptom Score questionnaire; satisfaction with urinary condition (quality-of-life measure); and visits to a doctor for urinary symptoms in the preceding 12 months. Results: The prevalence of one or more troublesome LUTS was 26% (318/1204) for men and 39% (662/1686) for women (all ages) and 48% (314/649) for men and women over 65. The most common troublesome symptoms in men and women were nocturia and frequency. Symptoms were significantly age-related in men, but less so in women, in whom symptom prevalence exceeded 30% for all age groups. Ten per cent of men (123/1204) and 15% of women (249/1686) had visited a doctor for a urinary problem in the previous 12 months. Nine per cent of men (104/1204) and 16% of women (274/1686) were substantially dissatisfied with their urinary condition. Symptom prevalence and dissatisfaction with urinary condition were significantly associated with visiting the doctor ( P < 0.0001), but only 28% (88/318) of men and 27% (179/662) of women with troublesome LUTS saw a doctor, and 63% (65/104) of men and 59% (162/274) of women dissatisfied with their urinary condition did not seek medical help. Conclusions: Although the prevalence of troublesome LUTS in the community is high, the number of people whose quality of life is substantially affected is much lower. The impact of these symptoms upon quality of life is a major reason for patients to see a doctor, yet many who are "bothered" by the symptoms do not do so. MJA 1997; 167: 72-75 Introduction As the community ages, conditions affecting the quality of life and activity of older people become of increasing concern. Lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH) have been termed "prostatism" and may greatly affect the quality of life of older men;1-3 the consequent cost of treatment to the community is high.4 The prevalence of clinically demonstrated BPH is 20% in men aged 40-49 years and 40%-50% in those over 65 years.1,5,6 To document the prevalence of symptoms related to BPH, the International Prostate Symptom Score (IPSS)7 grades the presence of seven LUTS (nocturia, intermittency, urgency, weak stream, incomplete emptying, hesitancy, frequency) on a severity scale of 0-5. It also includes a disease-specific quality-of-life question. However, LUTS measured with the IPSS and related symptom scores may have a range of aetiologies. Urinary symptoms such as urgency and urge incontinence may be caused by idiopathic detrusor instability, changes in muscle contractility, and other non-obstructive causes related to ageing.8,9 The IPSS is thus a non-specific measure of LUTS possibly caused by BPH, and this is reflected by studies that have shown high symptom scores in men with other lower urinary tract conditions,10 and in women.11-13 In an Australian general practice survey, urological problems were given as 1.7% of reasons for encounter with a doctor (all ages, both sexes),14 while in older men 7%-14% of encounters were for urinary problems.15 But the number of people significantly "bothered" by LUTS appears to be very much greater than the number seeking medical help for the problem.5,6,15 Symptom prevalence varies between countries, but there is evidence that similar levels of symptoms have a similar impact on daily activities of living in different countries.16,17 The prevalence of LUTS has been measured with the IPSS or related indices in the Netherlands,18 Canada,19 the United Kingdom,5 France,20 Japan,21 Spain,22 New Zealand,23 Scotland and the United States;17 no community-based surveys of symptom prevalence have been undertaken in Australia. Because of this, we undertook a community survey to determine the prevalence of troublesome LUTS in men and women in South Australia. The symptoms surveyed are described as uncomplicated by the National Health and Medical Research Council.8 Our objective was not to derive a severity score, but to determine the presence or absence of troublesome symptoms, their impact on quality of life, and the proportion of individuals seeking medical help for such a problem. Method Population surveyed The Omnibus survey, a multiple-user household interview survey undertaken for health organisations in South Australia (SA), was used for the study. The methodology and results of its use in other studies have been reported.24-26 The sampling method provides a probability sample of the SA population: in the metropolitan sample, 10 dwellings are chosen from each of 320 census collection districts (1991 census) using a random starting point and selection is then based on every fourth household. One person aged over 15 years (the person whose birthday was last) is chosen per household. In the country sample, all cities/towns with a population of 10 000 or more are chosen, and the balance of the sample is chosen from centres with a population of 1000 or more, with weighting proportional to size. The sampling method was the same as for metropolitan dwellings. Sixty interviewers conducted 3016 interviews from the 4200 households selected. Data are weighted by the inverse of the individual's probability of selection, then reweighted to benchmarks derived from estimated resident population at 30 June 1993 by age, sex and local government area from the Australian Bureau of Statistics. The data analysed and presented have thus been weighted to represent the age and sex structure of the SA population. Survey questionnaire The questions were derived from the American Urological Association-7 BPH questionnaire,27 adopted by the World Health Organization (WHO) as the IPSS,7 and have been validated for test/retest reliability, validity and clarity. Respondents were asked if, in the previous 12 months, any of the following urinary symptoms were troublesome: a strong need to urinate (pass water) with little or no warning; needing to go again less than two hours after finishing urination; needing to get up twice or more at night to urinate; having a weak urinary stream; stopping and starting several times when urinating; wetting underclothes;20 and whether there were other troublesome urinary symptoms. Respondents were asked about the presence or absence of "troublesome symptoms" -- they were not asked to grade symptom severity. They were also asked about quality-of-life7 (level of satisfaction with their urinary condition, in seven categories: delighted, pleased, mostly satisfied, mixed, mostly dissatisfied, unhappy, terrible), and whether they had seen a doctor about any urinary problem in the past 12 months. Questions were piloted for ease of understanding, internal consistency and sensitivity in a group of 18 men, and subsequently in 50 further interviews with men and women. To ensure completeness and accuracy of recording, five per cent of each interviewer's work was selected at random and the respondent re-interviewed with selected questions. After data checking, any missing responses were followed up by telephone. Statistical analysis was done with SPSS for Windows version 6.1 (SPSS, Chicago, Ill, USA). Statistical significance was calculated with Pearson chi-squared tests, unless otherwise indicated. Results The initial sample drawn was 4200 houses, of which 4067 were occupied and defined as "households". Of these, 3016 households participated, a response rate of 74.2%. Of the 3016 people interviewed, 1734 were women (57.5%) and 1281, men (42.5%). The major reasons for non-response were refusal (601; too busy, not interested) and contact not established after six visits (293); 75.6% of interviews were in the metropolitan area and 24.4% in the country. Respondents were evenly spread across all age groups. Only adults aged over 18 years are included in the analysis reported here (1204 men, 1686 women). Twenty-six per cent of men (318/1204) and 39% of women (662/1686) reported one or more troublesome urinary symptoms, with no differences between rural and metropolitan respondents (men or women) (Box 1). The most common symptoms in both men and women were frequency and nocturia (Box 2). In men, nocturia increased significantly with age (from 4% in 18- to 24-year-olds to 33% in those over 65 years; P < 0.00001). Weak stream also increased, from 2% in 18- to 24-year-olds to 12% in men over 65 (P < 0.00001). Urgency, frequency and mild incontinence were reported more frequently by women than by men (all, P < 0.001), and, as stated above, the overall prevalence of troublesome urinary symptoms (i.e, prevalence of more than one symptom) was also higher in women (P < 0.00001). The prevalence of one or more storage (irritative) symptoms (i.e., urgency, frequency or nocturia) was 23% in men and 33% in women (P < 0.0001), with the prevalence of one or more voiding (obstructive) symptoms (i.e., weak stream and intermittency) being 6.7% and 6.4%, respectively (difference not significant). Under the category "other", the most common symptom was stress incontinence (n= 17/44; 38%) in women and medication side-effects in men (n= 4/16; 25%). Age-specific symptom prevalence varied between men and women. For men, there was a clear age dependence, with symptom prevalence exceeding 20% only after age 45. In women, the age-related increase was weaker, and symptom prevalence exceeded 30% in all age groups. For men and women over 65, symptom prevalence was 48% (314/649). While the percentage of respondents reporting troublesome urinary symptoms was high (Box 1), only 28% of men (88/318) and 27% of women (179/662) with troublesome LUTS had visited a doctor about a urinary problem during the preceding 12 months. Satisfaction with urinary condition seems to be a better predictor of visits to the doctor than symptom prevalence (one or more symptoms) -- only 6% (23/397) who were "pleased" with their urinary condition had visited a doctor for urinary symptoms, compared with 60% (39/65) who were "unhappy" with their urinary condition (P < 0.00001). Discussion This first study of LUTS in the Australian community shows a high prevalence of troublesome LUTS, which occurred across all ages, but particularly in older age groups (48% of men and women over 65 reported one or more symptoms). Other reports also show a high prevalence of urinary symptoms for older men, ranging from 35% in a United States study28 to more than 90% of men in a Canadian study.19 Specific symptom prevalence can also be high (e.g., 61% for urgency,6 and 51% for hesitancy5 ). Most studies show that the prevalence of mild symptoms is high, and that symptoms which substantially affect quality of life or trigger a visit to the doctor have a lower prevalence.3 The prevalence of severe or bothersome symptoms is often as low as 25% to 30% of the total symptom prevalence,5,29 suggesting that adaptation to mild symptoms may occur. A review of moderate to severe symptoms in four community-based studies reported prevalence rates of 14%-33% for men over 40 years,16 and agrees with the 37% (220/593) of men over age 45 reporting one or more troublesome urinary symptoms in our study. In our study the most common troublesome symptoms for men were nocturia and frequency. This agrees with studies in France,20 the Netherlands,29 and the United Kingdom,5 but not Scottish studies1,6 or a French study.3 Methodological differences, such as the wording of questions and framing of population sampling methods, may account for these differences. In our study, the prevalence of urinary symptoms associated with "prostatism" in men was the same for men and women aged 55 and over (Box 2). Other studies in clinical or selected populations have also reported high symptom scores in women.11-13 However, we found the prevalence of LUTS in women did not show the same age-specific trend as for men, and storage symptoms (urgency, frequency and nocturia) were more prevalent in women (33% [563/1686] for one or more symptoms) than men (23% [274/1204]), while voiding symptoms were similar in both groups. In a study of women with voiding symptoms undergoing urodynamic evaluation, relatively few women had outflow obstruction.11 While the overall prevalence of LUTS, particularly in those aged 55 and over, was similar in men and women in our study, the symptom profile (age-specific trend and individual symptom prevalences) differed, reflecting their potentially different aetiologies. For both men and women, impact on quality of life (measured by satisfaction with urinary condition) was strongly correlated with visits to the doctor, with this correlation being similar in men and women. This argues against some reports of men's "stoicism" in the face of urinary symptoms.1 However, the finding also suggests that men and women may be equally reluctant to seek medical assistance for LUTS. Sixty-three per cent (65/104) of men and 59% (162/274) of women substantially dissatisfied with their urinary condition were not visiting a doctor for the condition, which agrees with the substantial numbers not seeking help reported in other studies.1,5 Conversely, the small proportion of our participants who had seen a doctor despite being "delighted" with their urinary condition may represent preventive activity, such as checkups, or concern, for example, about prostate cancer. Other studies report a substantial impact of moderate to severe LUTS on quality of life. Activities of daily living were affected in 51% of men with clinically defined BPH,1 and working-age men reported symptoms as more bothersome than retirement-age men, despite experiencing them less frequently.6 People may be reluctant to seek help for LUTS because these symptoms are considered a normal part of ageing, because of the perceived stigma of the symptoms or fear of possible treatments,1 or (in men) because of stoicism.30 These possibilities need to be addressed in future studies, as does the possibility that rural men who were dissatisfied with their urinary condition were less likely than urban men to seek medical help (P = 0.057). The main reason patients visit doctors about their urinary condition may be to reduce its effect on their daily activities, and this is therefore an objective of treatment. Conservative measures such as bladder training, pelvic muscle exercises, diet and fluid-intake management as well as attention to functional factors may be helpful in achieving this when symptoms are mild. Key points of study High prevalence of troublesome lower urinary tract symptoms (LUTS) in Australian men (26%) and women (39%). Far fewer men and women are substantially dissatisfied with their urinary condition (9% men, 16% women) and seeking treatment (10% men, 15% women). But fewer than half of those who are substantially dissatisfied with their urinary condition seek medical help (38% men, 41% women). LUTS in men and women has different aetiologies and symptom profiles, although the prevalence of one or more symptoms in people over the age of 65 years is the same (48%). The impact on quality of life is the major reason for people to seek medical help. Conservative management strategies may reduce this impact when surgical or medical treatment is not indicated. References Garraway WM, McKelvie GB, Russell EBA, et al. Impact of previously unrecognised benign prostatic hyperplasia on the daily activities of middle-aged and elderly men. Br J Gen Pract 1993; 43: 318-321. Abramson ZH, Gofin J, Abramson JH. Obstructive prostatic symptoms: a community survey in Jerusalem. Int J Epidemiol 1994; 23: 797-804. Sagnier P, MacFarlane G, Teillac P, et al. Impact of symptoms of prostatism on level of bother and quality of life of men in the French community. J Urol 1995; 153: 669-673. Ahlstrand C, Carlsson P, Jonsson B. Estimated total costs of treating benign prostatic hyperplasia in Sweden. Scand J Urol Nephrol 1995; 29: 57-63. Jolleys JV, Donovan JL, Nanchahal K, et al. Urinary symptoms in the community: how bothersome are they? Br J Urol 1994; 74: 551-555. Tsang KK, Garraway WM. Prostatism and the burden of benign prostatic hyperplasia on elderly men. Age Ageing 1994; 23: 360-364. Mebust W, Bosch R, Donovan J, et al. Symptom evaluation, quality of life and sexuality. In: Second international consultation on benign prostatic hyperplasia. Paris: World Health Organisation, 1993: 131-143. National Health and Medical Research Council. Clinical practice guidelines. The managment of uncomplicated lower urinary tract symptoms in men. Canberra: AGPS, 1996. Yalla SV. Correlation of American Urological Association Symptom Index with obstructive and non-obstructive prostatism. J Urol 1995; 153: 674-680. Stoevelaar H, van de Beek C, Nijs H, et al. The symptom questionnaire for benign prostatic hyperplasia: an ambiguous indicator for an ambiguous disease. Br J Urol 1996; 77: 181-185. Chancellor MB, Rivas DA. American Urological Association symptom index for women with voiding symptoms: lack of index specificity for benign prostate hyperplasia. J Urol 1993; 150: 1706-1709. Chai TC, Belville WD, McGuire EJ, Nyquist L. Specificity of the American Urological Association voiding symptom index: comparison of unselected and selected samples of both sexes. J Urol 1993; 150: 1710-1713. Lepor H, Machi G. Comparison of AUA symptom index in unselected males and females between 55 and 79 years of age. Urology 1993; 42: 36-40. Bridges-Webb C, Britt H, Miles D, et al. Morbidity and treatment in general practice in Australia 1990-1991. Med J Aust 1992; 157: Suppl Oct 19: S1-S57. Ward J, Sladden M. Urinary symptoms in older men, their investigation and management: is there an epidemic of undetected morbidity in the waiting room? Fam Pract 1994; 11: 251-259. Bosch R. Use of the International Prostate Symptom Score (IPSS) in epidemiological studies and clinical practice -- a review. In: Third International Consultation on Benign Prostatic Hyperplasia. Monaco: World Health Organisation, 1995. Guess HA, Chute CG, Garraway WM, et al. Similar levels of urological symptoms have similar impact on Scottish and American men -- although Scots report less symptoms. J Urol 1993; 150: 1701-1705. Bosch JL, Niemer AQ, Kirkels WJ, Schroder FH. Signs and symptoms of benign prostatic hyperplasia in men screened for prostatic carcinoma. Prog Clin Biol Res 1994; 386: 97-107. Norman RW, Nickel JC, Fish D, Pickett SN. 'Prostate-related symptoms' in Canadian men 50 years of age or older: prevalence and relationships among symptoms. Br J Urol 1994; 74: 542-550. Sagnier PP, MacFarlane G, Richard F, et al. Results of an epidemiological survey using a modified American Urological Association symptom index for benign prostatic hyperplasia in France. J Urol 1994; 151: 1266-1270. Tsukamoto T, Kumamoto Y, Masumori N, et al. Prevalence of prostatism in Japanese men in a community-based study with comparison to a similar American study. J Urol 1995; 154: 391-395. Hunter D, Berra-Unamuno A, Martin-Gordo A. Prevalence of urinary symptoms and other urological conditions in Spanish men 50 years old or older. J Urol 1996; 155: 1965-1970. Nacey J, Morum P, Delahunt B. Analysis of the prevalence of voiding symptoms in Maori, Pacific Island and Caucasian New Zealand men. Urology 1995; 46: 506-511. Wilson D, Wakefield M, Taylor A. The South Australian Health Omnibus Survey. Health Prom J Aust 1992; 2: 47-49. MacLennan A, Wilson D, Taylor A. Prevalence and cost of alternative medicine in Australia. Lancet 1996; 347: 569-573. MacLennan A, Taylor A, Wilson D. Changes in the use of hormone replacement therapy in South Australia. Med J Aust 1995; 162: 420-422. Barry MJ, Fowler F, O'Leary M, et al. The American Urological Association Symptom index for benign prostate hyperplasia. J Urol 1992; 148: 1549-1557. Diokno AC, Brown MB, Goldstein N, Herzog AR. Epidemiology of bladder emptying symptoms in elderly men. J Urol 1992; 148: 1817-1821. Bosch JL, Hop WC, Kirkels WJ, Schroder FH. The International Prostate Symptom Score in a community-based sample of men between 55 and 74 years of age: prevalence and correlation of symptoms with age, prostate volume, flow rate and residual urine volume. Br J Urol 1995; 75: 622-630. McCallum J. Older Men's Health: Stoicism versus successful ageing. Proceedings of the National Men's Health Conference. Melbourne: AGPS, 1995. (Received 24 June 1996, accepted 17 Feb 1997) Authors' details Repatriation General Hospital Daw Park, South Australia Carole Pinnock, PhD, Principal Research Scientist, Division of Surgery; Villis R Marshall, MD, FRACS, Professor and Head, Department of Surgery, Flinders Medical Centre, and Division of Surgery, Repatriation General Hospital Daw Park. Reprints: Dr CB Pinnock, Division of Surgery, Repatriation General Hospital Daw Park, Daws Road, Daw Park, SA 5041. E-mail: spinncb AT rgh.sa.gov.au ©MJA 1997 <URL: http://www.mja.com.au/> © 1997 Medical Journal of Australia.

Carole B Pinnock · Villis R Marshall

Consensus Statement Glycohaemoglobin: a crucial measurement in modern diabetes management Progress towards standardisation and improved precision of measurement* Peter G Colman, G Ian Goodall, Peter Garcia-Webb, Paul F Williams and Marjorie E Dunlop MJA 1997; 167: 96-98 Introduction - What is glycohaemoglobin and why should we measure it? - Types of assays available - Importance of reproducible measurement - How reliable are assays in Australia? - Progress towards standardisation - References - Authors' details - - More articles on Endocrinology Abstract Synopsis There are currently four principal glycohaemoglobin assay techniques (ion-exchange chromatography, electrophoresis, affinity chromatography and immunoassay) and about 20 different methods that measure different glycated products and report different units. Standardisation will lead to all assays reporting results in a standard unit, the HbA1c percentage of total serum haemoglobin, and should be in place within the next one to three years. In the interim, clinicians using glycohaemoglobin assays should be aware that the ranges indicating good and poor glycaemic control can vary markedly between different assays. The reproducibility of some assays may be insufficient to provide definitive evidence of changes in glycaemic control. Some assays may be so imprecise that they are unable to separate patients with good and poor control. Interim recommendations The terminology to be used for the assay is glycohaemoglobin (GHb) assay (recommendation from the combined meetings of the International Federation of Clinical Chemistry [IFCC] Working Group on HbA1c standardisation and the American Association of Clinical Chemistry [AACC] Subcommittee on Glycohemoglobin). The unit of measurement for GHb assays should be reported as %HbA1c (Diabetes Control and Complications Trial equivalent). Other units, such as % total GHb or %HbA1, should not be used. Assays producing these units should be converted to %HbA1c reporting units. Assays with high precision are highly desirable. The IFCC/AACC are currently recommending between-run coefficients of variation of less than 5% for manufacturers of kits and instruments. However, between-run coefficients of variation of less than 3% are far more clinically useful and therefore desirable. Introduction The landmark Diabetes Control and Complications Trial (DCCT)1 has focused increased attention on the importance of glycaemic control in preventing or retarding the progression of complications in patients with diabetes.2 Regular measurement of glycohaemoglobin is now recognised as an essential adjunct to self-measurement of blood glucose in achieving the best possible glycaemic control. However, clinicians using glycohaemoglobin assays should be aware of several potential problems which can confound the interpretation of the glycohaemoglobin result. What is glycohaemoglobin and why should we measure it? Glycohaemoglobin (GHb) is formed by a non-enzymatic interaction between glucose and the amino groups of the valine and lysine residues in haemoglobin. Formation of glycohaemoglobin is irreversible and the level in the red blood cell depends on the blood glucose concentration. Thus, measuring glycohaemoglobin provides a measurement of glycaemic control over time, and its use has been proven to evoke changes in diabetes treatment, resulting in improved metabolic control.3 First introduced in the 1970s, it is now accepted as a unique and important index of metabolic control and was a major outcome measure in the DCCT.1In the DCCT, 1441 patients with insulin-dependent diabetes were randomly allocated to intensive treatment and monitoring (usually with four insulin injections a day or pump treatment) with the aim of achieving normoglycaemia or to conventional treatment (usually with one or two injections a day). The effectiveness of intensive therapy was reflected in clear differences in mean blood glucose and glycohaemoglobin levels between the two groups. The intensive treatment group achieved a mean daily blood glucose level of 8.6 mmol/L and a median HbA1c value of 7.2% compared with the conventional treatment group, which achieved a mean blood glucose level of 12.8 mmol/L and a median HbA1c of 8.9%. These differences in glycaemic control were maintained over a mean period of 6.5 years and were associated with a 35%-76% reduction in retinopathy, nephropathy and neuropathy. Using the knowledge gained in the DCCT, doctors caring for patients with diabetes can now establish targets for glycaemic control that are based on observed outcomes, and which, if met, should minimise the development of complications. Inevitably, because glycohaemoglobin measurements reflect an integrated view of glycaemic control over time, the patients and their carers will place increasing reliance on the glycohaemoglobin result. So it is timely to evaluate the types of assays available, the moves toward standardisation of the reporting units and the precision and reproducibility of current assays. In the DCCT all glycohaemoglobin measurements were performed using the same closely standardised method. Unfortunately, in Australia there are currently four principal glycohaemoglobin assay techniques and about 20 different specific methods, most of which are not standardised between laboratories. Types of assays available The four principal techniques used to measure glycohaemoglobin are ion-exchange chromatography, electrophoresis, affinity chromatography and immunoassay. The techniques measure slightly different glycated products and use at least three different units for reporting the results (%HbA1c, %HbA1 and % total GHb). They can produce different values for the same patient specimen. This was demonstrated in a recent study in which four whole blood samples with HbA1c levels of 5.1% (representing non-diabetes), 6.7% (representing excellent glycaemic control), 8.5% (representing moderate glycaemic control) and 11.4% (representing poor glycaemic control) were distributed to 29 laboratories in Victoria for glycohaemoglobin determinations.4 The range of values obtained for the non-diabetic (4.1%-6.8%), good control (5.1%-9.3%), moderate control (6.7%- 11.9%) and poor control (10.1%-17.3%) specimens demonstrated extensive overlap between measurements of samples from patients with markedly different degrees of glycaemic control (Box 1). At present it is impossible to compare the results from two different laboratories; this can be confusing not only for patients but also for their carers. Laboratory- specific reference ranges are a means by which results from different laboratories can be compared, but the data used to derive such ranges are arbitrary and the categories into which different glycohaemoglobin levels are divided may be misleading. Importance of reproducible measurement A major use of the glycohaemoglobin assay is to assess changes in metabolic control that follow an alteration in treatment. The ability of any assay to reliably detect a change depends on its reproducibility (the ability of the assay and laboratory to get the same answer for the same sample each time). Reproducibility is normally expressed as the coefficient of variation (CV) of an assay. The CV is obtained by measuring the same sample at least 20 times in different assay runs and calculating the mean and standard deviation (SD) of the measurements; the CV is calculated by dividing the SD by the mean and expressing the result as a percentage. An assay with a high CV suffers from poor reproducibility and cannot demonstrate whether glycohaemoglobin levels have changed in different samples. Laboratories normally accept an assay for reporting purposes if the result for quality control samples falls within three SDs of the mean (3SD range). The imprecision of measurement of patient samples will be similar to that of the quality control samples. For example, if the result of an HbA1c assay with good precision (3% CV) was 7%, the 3SD range would be 6.37%-7.63%; for a result of 9%, the 3SD range would be 8.19%-9.81%. These two results can clearly be separated. In contrast, the same results of an assay with poor precision (6% CV) would have 3SD ranges of 5.74%-8.26% (for the 7% level) and 7.38%-10.62% (for the 9% level), and could not be differentiated. How reliable are assays in Australia? The Royal College of Pathologists of Australasia/Australasian Association of Clinical Biochemists Chemical Pathology Quality Assurance Programme provides external quality control samples for Australian laboratories that report glycohaemoglobin levels.5 The program runs on a six-monthly cycle, in which participating laboratories analyse two random samples per month, drawn from lyophilised whole blood samples representing six levels of glycohaemoglobin. The use of lyophilised samples can lead to minor variations in assay values for some methods. However, a recent study has excluded this as a complicating factor.6When measuring control samples with the value of 7.2% HbA1c (the mean outcome of intensive treatment in the DCCT), Australian laboratories reported HbA1c assay results between 6% and 9% HbA1c, while the range of values reported for all units (percentage of HbA1c, HbA1 and total GHb) was between 6% and 12.6%. When measuring control samples with the value of 8.9% HbA1c (the mean outcome level for conventional treatment in the DCCT trial), laboratories reported HbA1c values between 7.4% and 11%, while the range of values for all glycohaemoglobin units was 7.4% to 16.4%. The overlap between values obtained for these samples epitomises the problems currently facing clinicians in interpreting glycohaemoglobin levels and changes in levels reported by different laboratories. The interlaboratory CV obtained varied between 1.6% and 8.9% for the most common assays. To critically evaluate changes in HbA1c, the precision of individual laboratory assays for glycohaemoglobin must be known. For example, the difference in mean HbA1c value between the intensive and the conventional treatment groups in the DCCT was only 1.7%, and any assay used should at least be able to detect a difference of this order. With most laboratories using the 3SD range to accept or reject assay runs, glycohaemoglobin assays with CVs close to 3% are necessary to differentiate the two DCCT group means (Box 2). At 3% CV, the 3SD range of values for a patient with a true HbA1c level of 8.05 %HbA1c would be 7.33 to 8.77 %HbA1c. This range is less than ideal, but, realistically, only high pressure liquid chromatography assays currently achieve such precision. We recommend that the CV of the assay currently being used by the reporting laboratory be made available to carers who use glycohaemoglobin measurements. This will allow them to determine if the assay has the ability to differentiate between reported levels. Reference laboratories in the International Federation of Clinical Chemistry (IFCC)/American Association of Clinical Chemistry (AACC) International Standardization Programme must be able to achieve a CV below 3% at HbA1c levels of 6% and 9%.7 Manufacturers' assays should be able to achieve a CV below 5%. Currently, some GHb assays are unable to achieve these limits. Progress towards standardisation Standardisation is crucial to allow comparison of results obtained in different laboratories. A working party of the IFCC and AACC is coordinating an international effort by which all methods will be standardised to a designated method. This will be performed at the manufacturer level. Glycohaemoglobin analyser and kit manufacturers will have their assays standardised by reference laboratories established and monitored monthly by the IFCC/AACC working party. Thus, ultimately all laboratory methods will report their results in %HbA1c units which have been standardised against the DCCT method.8 Patients and carers will then be able to directly compare their level of glycaemic control against the enormous amount of data obtained by the DCCT trial on the onset and incidence of diabetes-related complications. References Larsen ML, Horder M, Mogensen EF. Effect of long-term monitoring of glycosylated hemoglobin levels in insulin-dependent diabetes mellitus. N Engl J Med 1990; 323: 1021-1025. Diabetes Control and Complications Trial Research Group. The effect of intensive treatment of diabetes on the development and progression of long term complications in insulin dependent diabetes mellitus. N Engl J Med 1993; 329: 977-986. Yue DK, Colagiuri S, McElduff A, Silink M. Diabetes Control and Complications Trial. Position Statement of the Australian Diabetes Society. Med J Aust 1993; 159: 803-804. Gilbert RE, Goodall I, Young V, Jerums G. Interlaboratory variation of GHb assays in Victoria, Australia. Diabetes Care 1996; 19: 730-734. Goodall I, Gill J, Penberthy L, Gilbert R. Interlaboratory variability of glycohaemoglobin. The Australian experience. In: Proceedings of the International Congress of Clinical Chemistry, 8-12 July, 1996 (editors: Martin SM, Halloran SP). Association of Clinical Biochemists, London, UK. July C 493 (ISSN 0959-9029), London, UK. Weykamp CW, Penders TJ, Muskiet FAJ, van der Slik W. Evaluation of reference material for glycated haemoglobin. Eur J Clin Chem Clin Biochem 1996; 34: 67-72. National Glycohemoglobin Standardization Program (NGSP) (Web site) http://www. missouri.edu/,diabetes/ngsp.html Hoelzel W, Miedema K. Development of a reference system for the international standardisation of HbA1c/glycohemoglobin determinations. J Int Fed Clin Chem 1996; 9: 62-67. * Consensus statement from the Australian Diabetes Society, the Royal College of Pathologists of Australasia and the Australasian Association of Clinical Biochemists Authors' details Department of Diabetes and Endocrinology, Royal Melbourne Hospital, Melbourne, VIC. Peter G Colman, FRACP, MD, Director. Special Chemistry Unit, Austin and Repatriation Medical Centre, Melbourne, VIC. G Ian Goodall, BSc, FAACB, Unit Manager. St John of God Pathology, Perth, WA. Peter Garcia-Webb, MD, FRCPA, Clinical Pathologist. Royal Prince Alfred Hospital, Sydney, NSW. Paul F Williams, MSc, PhD, Principal Hospital Scientist. University of Melbourne Department of Medicine, Melbourne, VIC. Marjorie E Dunlop, MSc, PhD, Principal Research Fellow. Reprints: Dr P G Colman, Department of Diabetes and Endocrinology, Royal Melbourne Hospital, PO Box 3050, Parkville, VIC 3050. E-mail: petercATnursing.medrmh.unimelb.edu.au Journalists are welcome to write news stories based on what they read here, but should acknowledge their source as "an article published on the Internet by The Medical Journal of Australia <http://www.mja.com.au>". <URL: http://www.mja.com.au/> 1: Results of glycohaemoglobin assays of four samples in 29 Victorian laboratories4 The four samples were from patients with differing degrees of diabetes control. The closed circles represent individual laboratory results for each sample and the open circles represent the notional target value. The notional target value was set by the Biorad Diamat (Biorad Laboratories, Hercules, California) in a laboratory where the assay was referenced against the DCCT method.2 Six methods of measuring glycohaemoglobin were used by the laboratories: High pressure liquid chromatography (cation exchange, measuring HbA1c)Immunoassay (measuring HbA1c)Ion exchange chromatography (manual assay, measuring HbA1c or HbA1)Affinity chromatography (measuring total GHb but expressed as either total GHb or %HbA1c)Electrophoresis (measuring HbA1c or HbA1)Low pressure liquid chromatography (measuring HbA1c and including HbF). Back to text Back to text

Peter G Colman · Peter Garcia-Webb · Paul F Williams · Marjorie E Dunlop