Canadian study of health and aging: study methods and prevalence of dementia.

OBJECTIVE: To estimate the prevalence of dementia and its subtypes by sex and age group for five regions of Canada. DESIGN: Prevalence survey. SETTING: Community and institutional settings in Canada, excluding those in the two territories, Indian reserves and military units. PARTICIPANTS: Representative sample of people aged 65 and over interviewed between February 1991 and May 1992. Those in the community (9008 subjects) were chosen randomly from medicare lists in nine provinces or from the Enumeration Composite Record in Ontario. People in institutions (1255) were randomly selected from residents in stratified random samples of institutions in each region. INTERVENTIONS: Screening with the Modified Mini-Mental State (3MS) Examination to identify cognitive impairment. Clinical examination of all those in institutions, those in the community with a 3MS score of less than 78 and a sample of those in the community with a 3MS score of 78 or more to diagnose dementia. Dementia and Alzheimer's disease were defined according to established criteria. MAIN OUTCOME MEASURES: Prevalence of dementia of all types, by region, sex and age group, the estimated number of cases in the population by type of dementia and the age-standardized rate per 1000 population. RESULTS: The prevalence estimates suggested that 252,600 (8.0%) of all Canadians aged 65 and over met the criteria for dementia (95% confidence interval [CI] 236,800 to 268,400). These were divided roughly equally between the community and institutional samples; the female:male ratio was 2:1. The age-standardized rate ranged from 2.4%, among those aged 65 to 74 years, to 34.5%, among those aged 85 and over. The corresponding figures for Alzheimer's disease were 5.1% overall (161,000 cases; 95% CI 148,100 to 173,900), ranging from 1.0% to 26.0%; for vascular dementia it was 1.5% overall, ranging from 0.6% to 4.8%. If the prevalence estimates remain constant, the number of Canadians with dementia will rise to 592,000 by 2021. CONCLUSIONS: These Canadian estimates of the prevalence of dementia fall toward the upper end of the ranges in other studies, whereas the estimates for Alzheimer's disease fall in the middle of the ranges. This may suggest an unusual balance between Alzheimer's and other forms of dementia in the Canadian population.     

The health of the very aged.

Little information is available on the health status of persons 85 years or over. Recent United States data indicate that 20% of individuals 85 years of age or over reside in nursing and personal care homes and that among these institutional residents 31% are bedfast, 11% are chairfast and 71% manifest evidence of senility. An investigation into the health of persons 85 years of age or over in two Ontario counties revealed that 39% resided in long-stay institutions, and that one of the main differences between old people living independently in the community and those in institutions was the higher proportion of the latter needing help with the activities of daily living and showing mental disorientation. Of those individuals 85 years of age or over in institutions for 1 year, 26% acknowledged often feeling depressed and 18% acknowledged often wishing they were dead, but these tendencies were not more frequent in those 85 years of age or over than in those 65 to 84 years of age. These findings have implications for service and research needs and attitudes towards death.     

Increased risk of suicide in persons with AIDS

The rate of suicide has been reported to be higher in persons with chronic and life-threatening illnesses (eg, cancer, Huntington's disease, and renal failure). We studied the rate of suicide in 1985 in New York City residents diagnosed with the acquired immunodeficiency syndrome (AIDS). There were 668 suicides in New York City residents in 1985, yielding a rate of 9.29 per 100,000 person-years. In men aged 20 to 59 years without a known diagnosis of AIDS, the rate was 18.75 per 100,000 person-years. There were 3828 individuals who lived with the diagnosis of AIDS for some part, or all, of 1985. There were 12 suicides in men aged 20 to 59 years from this group who lived 1763.25 person-years with a diagnosis of AIDS. This yields a suicide rate of 680.56 per 100,000 person-years. Thus, the relative risk of suicide in men with AIDS aged 20 to 59 years was 36.30 times (95% confidence limits, 20.45 to 64.42) that of men aged 20 to 59 years without this diagnosis, and 66.15 times (95% confidence limits, 37.38 to 117.06) that of the general population. We conclude that AIDS represents a significant risk factor for suicide.     

The effect of marital status on stage, treatment, and survival of cancer patients

The effects of marital status on the diagnosis, treatment, and survival of patients with cancer were examined in population-based data on 27,779 cancer cases. Unmarried persons with cancer had decreased overall survival (relative hazard, 1.23; 95% confidence limits, 1.19 to 1.28). We identified three complementary explanations for the poorer survival of the unmarried persons. First, unmarried persons were more likely to be diagnosed at a regional or distant stage (odds ratio, 1.19; 95% confidence limits, 1.12 to 1.25). After adjustment for stage, unmarried persons were more likely to be untreated for cancer (odds ratio, 1.43; 95% confidence limits, 1.31 to 1.55). Finally, after adjustment for stage and treatment, unmarried persons still had poorer survival. Previous studies have demonstrated that unmarried persons have decreased overall mortality. For cancer, our results suggest that the favorable consequence of being married on overall survival is secondary to the beneficial effects at several steps in the diagnosis, choice of treatment, and response to treatment.     

Epidemiology of invasive Streptococcus pneumoniae infections in the United States, 1995-1998: Opportunities for prevention in the conjugate vaccine era

CONTEXT: Pneumococcal polysaccharide vaccine is recommended for elderly persons and adults with certain chronic illnesses. Additionally, a recently licensed pneumococcal 7-valent conjugate vaccine has been recommended for use in young children and could dramatically change the epidemiology of pneumococcal disease. OBJECTIVES: To assess pneumococcal disease burden in the United States, estimate the potential impact of new vaccines, and identify gaps in vaccine recommendations. DESIGN AND SETTING: Analysis of data from the Active Bacterial Core Surveillance (ABCs)/Emerging Infections Program Network, an active, population-based system in 9 states. PATIENTS: A total of 15 860 cases of invasive pneumococcal disease occurring between January 1, 1995, and December 31, 1998. MAIN OUTCOME MEASURES: Age- and race-specific pneumoccocal disease incidence rates per 100 000 persons, case-fatality rates, and vaccine preventability. RESULTS: In 1998, overall incidence was 23.2 cases per 100 000, corresponding to an estimated 62 840 cases in the United States. Incidence was highest among children younger than 2 years (166.9) and adults aged 65 years or older (59.7). Incidence among blacks was 2.6 times higher than among whites (95% confidence interval [CI], 2.4-2.8). Overall, 28.6% of case-patients were at least 65 years old and 85.9% of cases in this age group were due to serotypes included in the 23-valent polysaccharide vaccine; 19.3% of case-patients were younger than 2 years and 82.2% of cases in this age group were due to serotypes included in the 7-valent conjugate vaccine. Among patients aged 2 to 64 years, 50.6% had a vaccine indication as defined by the Advisory Committee on Immunization Practices (ACIP). The case-fatality rate among patients aged 18 to 64 years with an ACIP indication was 12.1% compared with 5.4% for those without an indication (relative risk, 2.2; 95% CI, 1.7-2.9). CONCLUSIONS: Young children, elderly persons, and black persons of all ages are disproportionately affected by invasive pneumococcal disease. Current ACIP recommendations do not address a subset of persons aged 18 to 64 years but do include those at highest risk for death from invasive pneumococcal disease.     

老年人日常生活能力与某些疾病关系的社区调查

目的调查上海市老人日常生活能力（ＡＤＬ）状况及各类疾病发生率,分析痴呆综合征与其他疾病对老人ＡＤＬ的影响。方法采用我国修订版ＡＤＬ量表与疾病检询清单,经筛查和确诊,以３７４５名≥６５岁社区老人为分析样本,对６５～７４岁及≥７５岁两组分别予Ｌｏｇｉｓｔｉｃ多元回归分析,观察年龄、性别、文化程度及各类疾病变量对ＡＤＬ依赖的作用。结果ＡＤＬ依赖发生率达８．２８％,随年龄每增递１０岁,依赖发生成倍增长。疾病发生率（＞２０％）居前者的有高血压、心脏病、眼及关节疾病,痴呆为４．６１％。对两组老人影响最甚的疾病为脑卒中、震颤麻痹、痴呆、糖尿病及肺气肿。≥７５岁高龄组还析出癌症、动脉硬化、高血压等风险因子,痴呆的影响仍很显著。结论以Ａｌｚｈｅｉｍｅｒ′ｓ病为主的痴呆综合征是影响老人ＡＤＬ的严重疾病之一,亟待引起全社会的关注,应加强社区康复及医疗保健措施,以改进社区老人的生活质量。     

The definition of anemia in older persons.

CONTEXT: Whether hemoglobin concentrations defined as anemia by the World Health Organization (WHO) are associated with increased mortality in older persons is not known. OBJECTIVE: To investigate the association between hemoglobin concentration and cause-specific mortality in older persons. DESIGN: Community-based study conducted from 1986 to 1996 (follow-up period, 10 years). SETTING: Leiden, the Netherlands. PARTICIPANTS: A total of 1016 community residents aged 85 years and older were eligible and 872 agreed to have a blood sample taken. Hemoglobin concentration was measured in 755 persons (74%). MAIN OUTCOME MEASURES: Hemoglobin concentration, 10-year survival, and primary cause of death. According to the WHO criteria, anemia was defined as a hemoglobin concentration below 7.5 mmol/L (120 g/L) in women and below 8.1 mmol/L (130 g/L) in men. RESULTS: Compared with persons with a normal hemoglobin concentration, the mortality risk was 1.60 (95% confidence interval [CI], 1.24-2.06; P<.001) in women with anemia, and 2.29 (95% CI, 1.60-3.26; P<.001) in men with anemia. In both sexes, the mortality risk increased with lower hemoglobin concentrations. In persons without self-reported clinical disease at baseline, the mortality risk of anemia was 2.21 (95% CI, 1.37-3.57; P=.002). Mortality from malignant and infectious diseases was higher in persons with anemia. CONCLUSIONS: Anemia defined by the WHO criteria was associated with an increased mortality risk in persons aged 85 years and older. The criteria are thus appropriate for older persons. A low hemoglobin concentration at old age signifies disease.     

Breast cancer and oral contraceptives: findings in Oxford-Family Planning Association contraceptive study

Among the 17 032 women taking part in the Oxford-Family Planning Association contraceptive study, 72 were first diagnosed as having breast cancer between the date they were admitted to the study and 1 September 1980. The relative risk of developing the disease in women who had used oral contraceptives in comparison with those who had never used them was estimated to be 0.96 (95% confidence limits 0.59 to 1.63). Among women aged under 35 years, the corresponding relative risk (based on only 14 women with breast cancer) was estimated to be 0.61. No relation was apparent between the risk of developing breast cancer and duration of oral-contraceptive use or interval since first oral-contraceptive use in any age group. The data in this study are thus reassuring; but observations based on women with long-term use of oral contraceptives, especially those starting to use the preparations at an early age, are few.     

Acute rheumatic fever and rheumatic heart disease in a rural central Australian aboriginal community

A retrospective study of clinical case records was conducted at the health centre of a rural central Australian Aboriginal community to determine the frequency of acute rheumatic fever and of rheumatic heart disease between 1978 and 1987. The case records of 976 residents over 5 years of age were examined for evidence of the clinical indicators of acute rheumatic fever or rheumatic heart disease; together they contributed 8015 person-years of study. During the 10-year study period, 18 patients developed acute rheumatic fever and 12 patients had rheumatic heart disease. The annual incidence of acute rheumatic fever (first and recurrent attacks) for children aged 5-14 years was 815 per 100,000 person-years. For the residents aged 5 years and over, the point prevalence for rheumatic heart disease at the end of 1987 was between 7.9 and 12.3 per 1000 persons, according to health clinic records and the official population census, respectively. These rates are similar to those reported for Third World countries. Preventive measures must include efforts by health professionals to help to alleviate the adverse living conditions in Aboriginal communities.     

遵义市高血压流行特征及危险因素研究

目的　了解遵义市高血压流行特征及危险因素 ,为制定社区干预对策与措施提供依据。方法　采用分层整群抽样方法 ,对遵义市部份 4 0a及以上的中老年进行流行病学调查 ,危险因素采用 1:1病例对照研究。结果　遵义市 4 0a以上人口高血压患病率为 2 6 .2 % ,且随年龄增加而增加 ,农村高于城市 ,男性高于女性。体质指数(BMI)、腰 /臀比值 (WHR)、家族史、吸烟、饮酒是高血压的危险因素。OR值分别为 2 .6 5、2 .96、3.5 2、2 .17和 2 .2 3,各因素的 95 %CI分别为 1.5 1 4 .6 4、1.13 6 .6 7、1.87 6 .6 2、1.0 7 4 .39和 1.10 4 .5 2。结论　高血压是社区中老年人的主要疾病之一 ,需加强社区高血压的干预和预防     

High prevalence of coeliac disease in a population-based study from Western Australia: a case for screening?

OBJECTIVES: To determine the prevalence of coeliac disease in an Australian rural community. DESIGN: Retrospective analysis of stored serum samples from 3,011 random subjects from the Busselton Health Study. IgA antiendomysial antibodies (AEA) were detected by indirect immunofluorescence, and subjects testing positive were contacted and offered small-bowel biopsy. MAIN OUTCOME MEASURES: Prevalence of AEA positivity and biopsy-proven coeliac disease in the community with reference to the proportion of symptomatic to asymptomatic patients. RESULTS: 10 of 3,011 subjects were AEA positive. One subject had died, one subject could not be traced and one refused small-bowel biopsy. All subjects with detectable AEA who consented to biopsy had pathological changes consistent with coeliac disease. The prevalence of newly diagnosed biopsyproven coeliac disease is 7 in 3,011 (1 in 430). Two further subjects had a diagnosis of coeliac disease before this study. When all AEA-positive patients and those previously diagnosed are included, the prevalence is 12/3,011 (1 in 251). There was a significant clustering of cases in the 30-50-years age range, with 10/12 (83%; 95% CI, 52%-98%) aged between 30 and 50 years, compared with 1,092/3,011 (36%; 95% CI, 35%-38%) of the total population (P<0.03). Of the eight AEA-positive subjects who could be contacted, four had symptoms consistent with coeliac disease and four were asymptomatic. Three subjects were iron-deficient, four subjects had first-degree relatives with coeliac disease and one subject had type 1 diabetes mellitus. CONCLUSIONS: The prevalence of coeliac disease is high in a rural Australian community. Most patients are undiagnosed, and asymptomatic.     

West Indian diabetic population of a large inner city diabetic clinic

West Indians form a sizable minority of diabetics attending many inner city diabetic clinics. There are 554 diabetics of West Indian origin on our computer files--7% of the total recorded clinic population. Of these 554 patients (56% female, 44% male), 70% have been diagnosed within the past five years; and only 9% have had diabetes for over 10 years; in only five (1%) was diabetes diagnosed before the age of 20. Sixteen per cent were taking insulin, but only 4% of the total West Indian population were truly insulin dependent. Of 65 patients admitted in hyperglycaemic coma or precoma over the past three years, 10 were of West Indian origin; eight of these 10 had hyperosmolar coma compared with only six of the remaining 55. We conclude that diabetics of West Indian origin attending our clinic show differences in the distribution of age and duration of diabetes from the caucasian population. Most are non-insulin dependent, and the frequency of hyperosmolar coma is higher than that of ketoacidosis. Diabetics of West Indian origin may have a different pattern of disease from the rest of the clinic population.     

Effectiveness of a mass immunization campaign against serogroup C meningococcal disease in Quebec

CONTEXT: An outbreak of meningococcal disease in Quebec province prompted a mass immunization program. The impact of this campaign on the epidemiology of meningococcal disease has not been studied. OBJECTIVES: To study the impact of a mass immunization campaign using polysaccharide vaccine on the epidemiology of meningococcal disease (MCD) and to assess serogroup C vaccine effectiveness (VE). DESIGN, SETTING, AND SUBJECTS: Analysis of MCD cases reported in Quebec from 1990 to 1998, before and after the mass immunization campaign was conducted during the winter of 1992-1993, when 84% of residents aged 6 months to 20 years (the target population, approximately 1.9 million individuals) were vaccinated. MAIN OUTCOME MEASURES: Incidence of MCD in 1990-1998; incidence of culture-proven serogroup C MCD between April 1, 1993, and March 31, 1998, compared among vaccinated and unvaccinated persons in the target population. RESULTS: The incidence of serogroup C disease decreased after the mass immunization campaign, from 1.4 per 100 000 in 1990-1992 to 0.3 per 100 000 in 1993-1998, and the overall incidence of other serogroups remained stable at 0.7 per 100 000, with a small increase in the proportion of cases caused by serogroup Y (P =.009). Protection from serogroup C MCD was indicated in the first 2 years after vaccine administration (VE, 65%; 95% confidence interval [CI], 20%-84%), but not in the next 3 years (VE, 0%; 95% CI, -5% to 65%). Vaccine effectiveness was strongly related to age at vaccination: 83% (95% CI, 39%-96%) for ages 15 through 20 years, 75% (95% CI, - 17% to 93%) for ages 10 through 14 years, and 41% (95% CI, -106% to 79%) for ages 2 through 9 years. There was no evidence of protection in children younger than 2 years; all 8 MCD cases in this age group occurred in vaccinees. CONCLUSIONS: Serogroup C polysaccharide vaccine is effective for controlling outbreaks in teenaged individuals but should not be used in children younger than 2 years. The mass campaign did not induce significant serogroup switching.     

The natural history of hepatitis C virus infection: host, viral, and environmental factors

CONTEXT: Hepatitis C virus (HCV) infection may resolve (viral clearance), persist without complications, or cause end-stage liver disease (ESLD). The frequency and determinants of these outcomes are poorly understood. OBJECTIVE: To assess the incidence and determinants of viral clearance and ESLD among persons who acquired HCV infection from injection drug use. DESIGN AND SETTING: Community-based prospective cohort study with enrollment in 1988-1989 and a median follow-up of 8.8 years. SUBJECTS: A total of 1667 persons aged 17 years or older with a history of injection drug use and an HCV antibody-positive test result during follow-up. MAIN OUTCOME MEASURES: Viral clearance was assessed in a subset of 919 patients and defined as failure to detect HCV RNA in at least 2 consecutive samples collected 5 or more months apart. End-stage liver disease was assessed at semiannual visits and by review of medical records and death certificates and defined by the presence of ascites, esophageal varices, or hepatic encephalopathy, or when ESLD was stated as a cause of death. RESULTS: Viral clearance was observed in 90 persons who were compared with 722 with persistent viremia, while the viremia of 107 was not resolved. Viral clearance occurred more often in nonblacks (adjusted odds ratio [OR], 5.15; 95% confidence interval [CI], 2.60-10.17) and those not infected with human immunodeficiency virus (HIV) (adjusted OR, 2.19; 95% CI, 1.26-3.47). Forty cases of ESLD were observed throughout follow-up (incidence, 3.1 per 1000 person-years). In a multivariate model, risk of ESLD was higher for persons aged 38 years or older at enrollment (adjusted relative incidence, 3.67; 95% CI, 1.96-6.88) and who reported ingestion of more than 260 g of alcohol per week (adjusted relative incidence, 3.60; 95% CI, 1.73-7.52). Of 210 patients without ESLD randomly selected for biopsy, only 2 had cirrhosis. CONCLUSIONS: Our results indicate that although HCV infection can be self-limited or associated with ESLD, the majority of adults have persistent viremia without clinically demonstrable liver disease. Further research is needed to explain the less frequent clearance of HCV infection among black persons and to improve utilization of treatment for those infected in the context of injection drug use. JAMA. 2000;284:450-456     

湖北省十堰市居民对慢性肾脏病知识知晓程度的调查分析

目的对十堰市居民进行慢性肾脏病(CKD)知识知晓程度的调查,为十堰市居民CKD防治提供基础资料。方法于2010年5月至2011年10月对十堰市居民进行问卷调查,采用横断面调查,从十堰市分层整群抽取70个厂矿、机关、学校、社区及乡镇18岁以上常住居民5230人,采用自行设计的CKD知识知晓程度调查表,并对调查结果进行统计分析。结果共发放调查表5230份,收回有效调查表5219份,总体知晓率为20.71%(1081人),4.58%(239人)能正确了解CKD,73.81%(3852人)不了解尿毒症及血液透析,72.27%(3772人)从未行肾脏相关检查;对CKD的发病症状、发病后的就诊科室、检查手段知晓率分别为34.13%(1781人)、58.15%(3035人)、33.34%(1740人);对CKD危险因素、治疗措施知晓率更低,分别为17.09%(892人)、11.61%(606人)。多因素分析结果显示,CKD的知晓率与文化程度及职业呈正相关(χ2=115.021、92.552,P<0.01),与年龄呈负相关(χ2=42.383,P<0.01)。结论十堰地区居民对CKD相关知识缺乏了解,需要医务工作者加大对CKD相关知识的宣教力度,以提高十堰市居民对CKD的知晓水平,达到对CKD早预防、早诊断、早治疗的目的。     

Prevalence of carpal tunnel syndrome in a general population.

CONTEXT: Carpal tunnel syndrome (CTS) is a cause of pain, numbness, and tingling in the hands and is an important cause of work disability. Although high prevalence rates of CTS in certain occupations have been reported, little is known about its prevalence in the general population. OBJECTIVE: To estimate the prevalence of CTS in a general population. DESIGN: General health mail survey sent in February 1997, inquiring about symptoms of pain, numbness, and tingling in any part of the body, followed 2 months later by clinical examination and nerve conduction testing of responders reporting symptoms in the median nerve distribution in the hands, as well as of a sample of those not reporting these symptoms (controls). SETTING: A region in southern Sweden with a population of 170000. PARTICIPANTS: A sex- and age-stratified sample of 3000 subjects (age range, 25-74 years) was randomly selected from the general population register and sent the survey, with a response rate of 83% (n = 2466; 46% men). Of the symptomatic responders, 81% underwent clinical examination. MAIN OUTCOME MEASURES: Population prevalence rates, calculated as the number of symptomatic responders diagnosed on examination as having clinically certain CTS and/or electrophysiological median neuropathy divided by the total number of responders. RESULTS: Of the 2466 responders, 354 reported pain, numbness, and/or tingling in the median nerve distribution in the hands (prevalence, 14.4%; 95% confidence interval [CI], 13.0%-15.8%). On clinical examination, 94 symptomatic subjects were diagnosed as having clinically certain CTS (prevalence, 3.8%; 95% CI, 3.1%-4.6%). Nerve conduction testing showed median neuropathy at the carpal tunnel in 120 symptomatic subjects (prevalence, 4.9%; 95% CI, 4.1%-5.8%). Sixty-six symptomatic subjects had clinically and electrophysiologically confirmed CTS (prevalence, 2.7%; 95% CI, 2.1%-3.4%). Of 125 control subjects clinically examined, electrophysiological median neuropathy was found in 23 (18.4%; 95% CI, 12.0%-26.3%). CONCLUSION: Symptoms of pain, numbness, and tingling in the hands are common in the general population. Based on our data, 1 in 5 symptomatic subjects would be expected to have CTS based on clinical examination and electrophysiologic testing.     

Prevalence study on dementia and Alzheimer disease

An epidemiological survey on dementia and Alzheimer disease (AD) was carried out in a community of 5055 persons over the age of 55 at Jingan district of Shanghai. Diagnoses were made according to the diagnostic criteria of dementia of DSM-III-R and of AD of NINCDS-ADRDA. It was found that dementia is not uncommon in the aged, and AD was the leading category of dementia. The age and sex adjusted prevalence rate of dementia was 2.57% in those over 55, 3.46% in those over 60, and 4.61% in those over 65, and that of AD was 1.50%, 2.05% and 2.90% respectively. Beside age, the other risk factors were female sex, bereavement of spouse, low education and unfavorable socio-economic status.     

Admissions, patterns of utilization and disposition of cases of acute stroke in Brisbane hospitals

In a population of slightly-more than one million persons, all cases of acute admission to hospital for cerebrovascular disease during 1984 were studied. Of the 2676 hospital admissions, 91% were of public-hospital patients. Of the 1908 patients who were aged more than 25 years and whose conditions were assigned the International classification of diseases' (ICD-9) codes (430-437) for cerebrovascular accidents, 1264 (1.8 patients per 1000 population of older than 25 years of age) cases were completed strokes, and 644 (1.0 patients per 1000 population of older than 25 years of age) cases were transient ischaemic attacks. There was no significant difference between the specific aetiological types of stroke that were diagnosed neuroradiologically and those that were diagnosed clinically. Among the cases of completed strokes, 54% of cases were thrombotic, 11% of cases were embolic, and 15% of cases were haemorrhagic, while nearly 20% of cases were unclassified. Twenty-one per cent of patients who were admitted to hospital with completed strokes died within two weeks of their admission, 28% of such patients were discharged home, 8% of such patients were transferred to full-maintenance care, and the remaining 43% of such patients were transferred for inpatient rehabilitation. The median length of stay for patients with completed strokes was 11.8 days compared with 6.2 days for patients with transient ischaemic attacks.     

Prevalence of heart failure and systolic ventricular dysfunction in older Australians: the Canberra Heart Study

OBJECTIVE: To estimate the prevalence of heart failure (HF) and left ventricular (LV) systolic dysfunction in a population-based sample of older Australians. DESIGN, SETTING AND PARTICIPANTS: A cross-sectional survey of 2000 randomly selected residents of Canberra, aged 60-86 years, conducted between February 2002 and June 2003. Participants were assessed by history, physical examination by a cardiologist, and echocardiography. MAIN OUTCOME MEASURES: Age- and sex-specific prevalence rates of clinical HF and LV systolic dysfunction (defined as LV ejection fraction < or = 50%). RESULTS: Of 1846 people eligible for our study, 1388 (75%) agreed to participate and 1275 completed all investigations (mean age, 69.4 years; 50% men). In the study sample, 72 subjects (5.6%; 95% CI, 4.4%-7.1%) had clinical HF that had been previously diagnosed and was confirmed by our assessment. A further 0.6% (95% CI, 0.3%-1.2%) had undiagnosed clinical HF (ie, evidence of structural heart disease and symptoms/signs of cardiac insufficiency without a previous diagnosis of clinical HF). Thus, the overall prevalence of clinical HF in the sample was 6.3% (95% CI, 5.0%-7.7%). Clinical HF increased in prevalence with advancing age (a 4.4-fold increase from the 60-64-years age group to the 80-86-years age group; P < 0.0001). Of the 75 subjects (5.9%; 95% CI, 4.7%-7.3%) with LV systolic dysfunction, 44 (59%) were in the preclinical stage of disease. CONCLUSION: Diagnosed HF cases represent the "tip of the iceberg" for the national burden of HF and LV systolic dysfunction. Clinically identifiable HF cases can remain undiagnosed, and the majority of people with LV systolic dysfunction are in a preclinical stage of the disease.