Trends in hospital admissions and mortality from asthma and chronic obstructive pulmonary disease in Australia, 1993-2003

OBJECTIVE: To examine evolving changes in asthma and chronic obstructive pulmonary disease (COPD) in South Australia and Australia as a whole from the perspective of hospital admissions, ventilatory support and mortality data. DESIGN: Retrospective analyses, for the period 1993-2003, of hospital separations data from the Australian Institute of Health and Welfare and the Integrated South Australian Activity Collection, and mortality data from the Australian Bureau of Statistics and South Australian hospital morbidity collection. MAIN OUTCOME MEASURES: Hospital separations, ventilatory support episodes, mortality rates, burden-of-disease rankings. RESULTS: Between 1993 and 2003, in SA and nationally, hospital separations for asthma declined but separations for COPD increased significantly. Falling mortality rates from asthma in both men and women, and from COPD in men, contrast with increasing rates of COPD-related hospitalisation and mortality in women. CONCLUSIONS: Hospital admissions and mortality associated with asthma have fallen. Admission rates for COPD are declining for men, but there is no indication that admission rates for women have reached a peak. There is a need for higher prioritisation of COPD, including policies to reduce smoking in women, and medical practice initiatives to support primary and secondary prevention, pulmonary rehabilitation and appropriate drug therapies.     

Climatic temperature and variation in the incidence of sudden infant death syndrome between the Australian states.

OBJECTIVE: To describe the relationship between climatic temperature and the incidence of sudden infant death syndrome (SIDS) for the Australian States and examine the extent to which differences in climatic temperature might explain the regional variation of SIDS in Australia. DESIGN: Case series study. A generalised linear model was used to model the association between monthly average temperature and the incidence of SIDS. SETTING: The report is population based. Data are available from all Australian States. SUBJECTS: Cases of SIDS from birth to less than 12 months of age occurring in Queensland (1981-1987), New South Wales (1981-1987), Victoria (1984-1987), Tasmania (1975-1989), South Australia (1980-1989), and Western Australia (1980-1988). RESULTS: Every one degree Celsius decrease in average monthly temperature within the range 9 degrees C to 25 degrees C is associated with a 10.6% (95% confidence interval, 9.6%-11.7%) increase in the incidence of SIDS. Climatic temperature accounts for 84% of the interstate variation in the rate of SIDS. After controlling for the effect of temperature, a significant overall difference in SIDS incidence remains (P less than 0.0001) for the Australian States. CONCLUSION: Climatic temperature accounts for most but not all of the regional variation of SIDS incidence in the Australian States. The remaining variation may reflect differences in the maternal and infant characteristics of the State populations.     

Tuberculosis surveillance in the South Australian aboriginal community

Tuberculosis (TB) is still a significant problem in Aboriginal people. There are higher rates of active TB and evidence of continuing transmission among this group. We sought to define the specific epidemiological risks and best methods of surveillance for TB in Aboriginal people in South Australia. We compared the incidence of active TB in Aboriginal people in South Australia with that of the total number of cases in non-Aboriginal people from 1978 to 1988, and studied the prevalence of infection in four Aboriginal communities in South Australia. Incidence rates of active TB were four times higher in South Australian Aboriginal people than the total South Australian rates. Specific age analysis revealed higher active disease notification rates in Aboriginal people aged 45-54 years and 55-64 years. The notification rate for Aboriginal men was almost three times the rate for women. Standardized incidence ratios of active TB cases for Aboriginal communities were higher in rural and traditional communities than in urban Aboriginal people. Infection prevalence, measured by tuberculin skin testing, varied from 7.7% to 30.8% in the different communities but did not correlate with the standardized incidence ratios. We conclude that (i) South Australian Aboriginal people are suffering a higher rate of active TB disease than the total South Australian community, and (ii) that the disease and infection rates vary between communities and between age and sex groups. The discrepancy between disease notifications rates, as measured by standardized incidence ratios, and infection prevalence requires further investigation. To improve TB control in Aboriginal people, programmes need to be altered to be more appropriate for this group.     

Lung cancer in New South Wales: current trends and the influence of age and sex

OBJECTIVE: To examine the effects of time, sex and age at diagnosis on lung cancer incidence rates and the distribution of the histological types of lung cancer in New South Wales. DESIGN AND SETTING: Retrospective analysis of data from the NSW Cancer Registry and Australian Bureau of Statistics population data for NSW for 1985-1995. MAIN OUTCOME MEASURES: Trends in lung cancer incidence rates between 1985 and 1995 for men and women aged over 30 years; changes in incidence rates within age groups; and incidence rates of histological subtypes relative to sex and age. RESULTS: The incidence of lung cancer in men aged 40-80 years fell, while that in women aged over 65 rose. Rates were stable in younger women and older men. Incidence rates in men aged 40-60 years fell by 40%-60%. Were it not for the reduction in incidence rates in men between 1985 and 1995, the number of male lung cancer cases in 1995 would have been greater by 389 (95% CI, 362-415). In women, increasing incidence rates were responsible for an extra 242 cases (95% CI, 232-253) in 1995. Adenocarcinoma comprised a greater percentage of lung cancer cases in younger people, while squamous-cell carcinoma increases steadily with age in both men and women. Women with lung cancer are less likely to have squamous-cell carcinoma (25% for women v. 40% for men) and therefore more likely than men to have adenocarcinoma (35% of new female cases v. 26% for men) or small-cell lung cancer (24% v. 19%). CONCLUSIONS: Increased smoking cessation has seen a halving of lung cancer rates in middle-aged men. Whether this represents delayed or prevented cases is uncertain. The distribution of histological subtypes of lung cancer in women is different from that in men, and it is not clear whether this difference is hormone-dependent or related to historical patterns of smoking.     

Firearms suicides in Australia.

OBJECTIVE: To examine the rates of suicide by firearms in the five larger Australian States during 1968-1989, and to relate them to differences between those States. We hypothesised that (i) restrictive gun legislation will have reduced the firearms suicide rate in South Australia after 1980, and (ii) firearms suicides would be shown to be more common in States with larger rural:urban population ratios. DESIGN: Data supplied by the Australian Bureau of Statistics were analysed by sex, State and year of suicide. Differences between the firearms suicide rates of capital city and rural dwellers, and of different age-groups, were recorded. RESULTS: Firearms suicide rates in South Australia declined significantly after 1980, following proclamation of gun legislation, in contrast to the four other larger States where an increase in firearms suicides was recorded. The firearms suicide rate in Queensland has remained consistently higher than in the other four larger States during 1968-1989. The number of Australian firearms suicides per year fell by 25% from a peak of 572 in 1987 to 451 in 1989. CONCLUSIONS: Further reductions in the Australian firearms suicide rate might be achieved by tightening gun laws and by a media campaign aimed at reducing easy access by males to guns in rural households.     

Cancer case-survival rates for South Australia: a comparison with US rates and a preliminary investigation of time trends

Five-year relative case-survival rates for all cancers collectively are similar in South Australia (49%) and the United States (50%). This suggests that outcomes of cancer treatment do not vary appreciably between the two populations. There is an indication of higher survival rates in South Australia for melanoma, Hodgkin's disease, multiple myeloma and gastric cancer, but lower survival rates for cancers of the thyroid, corpus uteri, prostate, colon, kidney and lung. The differences in point estimates of the rates were most conspicuous for Hodgkin's disease, multiple myeloma and prostatic cancer. The reasons for a cautious interpretation of these findings are discussed and some possible explanations are suggested. South Australian data point to an upward trend in survival rates between the diagnostic periods 1977-1980 and 1981-1985 for patients with Hodgkin's disease, diffuse large-cell lymphomas, melanomas and cancers of the prostate and rectum.     

Decrease in breast cancer incidence following a rapid fall in use of hormone replacement therapy in Australia

OBJECTIVE: To determine if the recent rapid fall in use of hormone replacement therapy (HRT) in Australia has been followed by a reduction in breast cancer incidence among women aged 50 years or older, but not among younger women. DESIGN AND SETTING: Analysis of trends in annual prescribing of HRT, using Pharmaceutical Benefits Scheme data, and in annual age-standardised breast cancer incidence rates in Australian women for the period 1996-2003. RESULTS: In Australia, prescribing of HRT increased from 1996 to 2001, but dropped by 40% from 2001 to 2003. Age-standardised breast cancer incidence rates in women aged > or = 50 years also increased to 2001 but declined thereafter. The incidence rates in this age group were lower by 6.7% (95% CI, 3.9%-9.3%; P < 0.001) in 2003 compared with 2001, equivalent to 600 (95% CI, 350-830) fewer breast cancers (out of about 9000 incident breast cancers annually for women this age). There was no significant change in breast cancer incidence for women aged < 50 years. CONCLUSIONS: While other factors may have contributed to a recent reduction in breast cancer incidence among Australian women aged > or = 50 years, the available evidence suggests that much of the decrease is due to the recent fall in use of HRT. This is consistent with other evidence that the HRT-associated increase in risk of breast cancer is reversible after ceasing use of HRT.     

Primary hepatocellular carcinoma in Australia, 1978-1997: increasing incidence and mortality

OBJECTIVES: To describe trends in primary hepatocellular carcinoma (HCC) incidence and mortality in Australia between 1978 and 1997, and to delineate the effects of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection by examining cases of HCC in Australian-born and overseas-born people separately. DESIGN AND SETTING: Retrospective analysis of national incidence and mortality data in which the underlying cause was coded as HCC (International classification of diseases, ninth revision [ICD-9] code 155.0). MAIN OUTCOME MEASURES: Changes in age-standardised HCC incidence rates in men and women between 1983 and 1996; age-standardised HCC death rates in Australian-born and overseas-born men and women between 1978 and 1997. RESULTS: Age-standardised incidence rates increased in men and women (from 2.06 and 0.57 per 100,000 respectively in 1983-1985 to 3.97 and 0.99 respectively in 1995-1996). Age-standardised death rates increased in Australian-born and overseas-born men and overseas-born women (from 1.43, 2.35 and 0.62 respectively per 100,000 in 1978-1982 to 2.50, 4.41 and 1.36 respectively in 1993-1997). However, death rates in Australian-born women did not increase (0.58 per 100,000 in 1978-1982 and 0.63 in 1993-1997). CONCLUSIONS: HCC incidence and death rates in Australia have increased over the past two decades, except in Australian-born women. A likely explanation for at least a portion of this increase is increased prevalences of HBV and HCV infection in Australia.     

Rising incidence of renal cell cancer in the United States

CONTEXT: Clinical surveys have revealed that incidental detection of renal cell carcinoma is rising because of increased use of imaging procedures. OBJECTIVE: To examine incidence, mortality, and survival trends of renal cell and renal pelvis cancers by age, sex, race, and tumor stage at diagnosis. DESIGN: Calculation of age-adjusted incidence and mortality rates, along with 5-year relative survival rates, using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program. SETTING AND PARTICIPANTS: Patients diagnosed as having kidney cancer from 1975 through 1995 in the 9 geographic areas covered by tumor registries in the SEER program, which represent about 10% of the US population. MAIN OUTCOME MEASURES: Incidence, mortality, and 5-year relative survival rates by time periods. RESULTS: The age-adjusted incidence rates for renal cell carcinoma between 1975 and 1995 for white men, white women, black men, and black women were 9.6, 4.4, 11.1, and 4.9 per 100000 person-years, respectively. The corresponding rates for renal pelvis cancer were 1.5, 0.7, 0.8, and 0.5 per 100000 person-years. Renal cell cancer incidence rates increased steadily between 1975 and 1995, by 2.3% annually among white men, 3.1 % among white women, 3.9% among black men, and 4.3% among black women. Increases were greatest for localized tumors but were also seen for more advanced and unstaged tumors. In contrast, the incidence rates for renal pelvis cancer declined among white men and remained stable among white women and blacks. Although 5-year relative survival rates for patients with renal cell cancer improved among whites but not among blacks, kidney cancer mortality rates increased in all race and sex groups. CONCLUSIONS: Increasing detection of presymptomatic tumors by imaging procedures, such as ultrasonography, computed tomography, and magnetic resonance imaging, does not fully explain the upward incidence trends of renal cell carcinoma. Other factors may be contributing to the rapidly increasing incidence of renal cell cancer in the United States, particularly among blacks.     

Congenital heart defects in Central Australia

OBJECTIVE: To determine the incidence of congenital heart defects (CHD) in Aboriginal and non-Aboriginal infants in Central Australia and to compare this with the incidence elsewhere in Australia. DESIGN AND SETTING: Data on cases were obtained from patient records of the Alice Springs Hospital, Central Australia, the sole referral centre for paediatric and initial cardiac diagnostic services for the region. PARTICIPANTS: Patients with CHD proven by echocardiography reported between 1 January 1993 and 30 June 2000. MAIN OUTCOME MEASURES: Incidence of CHD using all live births in Central Australia as the denominator. RESULTS: 108 patients with CHD were detected among 6156 live births (incidence, 17.5 per 1000; 95% CI, 14.9-21.7 per 1000); 57 of 2991 were Aboriginal (19.0 per 1000; 95% CI, 14.4-24.6 per 1000) and 51 of 3165 were non-Aboriginal (16.1 per 1000; 95% CI, 12.0-21.1 per 1000). The difference between the two groups was not statistically significant (relative risk, 1.18; 95% CI, 0.81-1.72). CHD incidence in Central Australia was significantly higher than that reported for other parts of Australia (4.3 per 1000 live births in New South Wales and the Australian Capital Territory, 1981-1984; 7.65 and 12 per 1000 total births in Western Australia, 1980-1989, and South Australia, 1993-2000, respectively). CONCLUSIONS: The high rates of CHD in Central Australia may partly reflect the high utilisation of echocardiography for assessing minor lesions. However, the incidence of both major and minor types of CHD was significantly higher than previously reported from other regions of Australia. The role of socioenvironmental factors in this high incidence should be explored.     

Opioid overdose mortality in Australia, 1964-1997: birth-cohort trends.

OBJECTIVE: To examine trends in rates of opioid overdose deaths from 1964 to 1997 in different birth cohorts. DESIGN: Age-period-cohort analysis of national data from the Australian Bureau of Statistics. MAIN OUTCOME MEASURES: Annual population rates of death attributed to opioid dependence or accidental opioid poisoning in people aged 15-44 years, by sex and birth cohort (in five-year intervals, 1940-1944 to 1975-1979). RESULTS: The rate of opioid overdose deaths increased 55-fold between 1964 and 1997, from 1.3 to 71.5 per million population aged 15-44 years. The rate of opioid overdose deaths also increased substantially over the eight birth cohorts, with an incidence rate ratio of 20.70 (95% confidence interval, 13.60-31.46) in the 1975-1979 cohort compared with the 1940-1944 cohort. The age at which the cumulative rate of opioid overdose deaths reached 300 per million fell in successive cohorts (for men, from 28 years among those born 1955-1959 to 22 years among those born 1965-1974; for women, from 33 years among those born 1955-1959 to 27 years among those born 1965-1969). CONCLUSIONS: Heroin use in Australia largely began in the early 1970s and rates of heroin use have markedly increased in birth cohorts born since 1950.     

Overweight, obesity and metabolic syndrome in rural southeastern Australia

OBJECTIVE: To measure the prevalence of overweight, obesity and the metabolic syndrome (MetS) in rural Australia. DESIGN, SETTING AND PARTICIPANTS: Cross-sectional surveys were conducted in two rural areas in Victoria and South Australia in 2004-2005. A stratified random sample of men and women aged 25-74 years was selected from the electoral roll. Data were collected by a self-administered questionnaire, physical measurements and laboratory tests. MAIN OUTCOME MEASURES: Prevalence of overweight and obesity, as defined by body mass index (BMI) and waist circumference; prevalence of MetS and its components. RESULTS: Data on 806 participants (383 men and 423 women) were analysed. Based on BMI, the prevalence of overweight and obesity combined was 74.1% (95% CI, 69.7%-78.5%) in men and 64.1% (95% CI, 59.5%-68.7%) in women. Based on waist circumference, the prevalence of overweight and obesity was higher in women (72.4%; 95% CI, 68.1%-76.7%) than men (61.9%; 95% CI, 57.0%-66.8%). The overall prevalence of obesity was 30.0% (95% CI, 26.8%-33.2%) based on BMI (> or = 30.0 kg/m(2)) and 44.7% (95% CI, 41.2%-48.1%) based on waist circumference (> or = 102 cm [men] and > or= 88 cm [women]). The prevalence of MetS as defined by the US National Cholesterol Education Program Adult Treatment Panel III 2005 criteria was 27.1% (95% CI, 22.7%-31.6%) in men and 28.3% (95% CI, 24.0%-32.6%) in women; based on International Diabetes Federation criteria, prevalences for men and women were 33.7% (95% CI, 29.0%-38.5%) and 30.1% (95% CI, 25.7%-34.5%), respectively. Prevalences of MetS, central (abdominal) obesity, hyperglycaemia, hypertension and hypertriglyceridaemia increased with age. CONCLUSIONS: In rural Australia, prevalences of MetS, overweight and obesity are very high. Urgent population-wide action is required to tackle the problem.     

Estimating Australia's abortion rates 1985-2003

AIM: To estimate national rates of induced abortion in Australia from 1985 to 2003, using Medicare claim statistics for private patients and hospital morbidity statistics for public patients. DESIGN AND SETTING: Estimates were based on Australian and South Australian data collections relating to abortions. SA hospital morbidity statistics were compared with SA statutory notifications of abortions to estimate the accuracy of these collections. Medicare statistics on abortion procedures performed on private patients in South Australia were then compared with hospital morbidity statistics for private patients. National statistics on abortion derived from Medicare and hospital morbidity statistics were adjusted for inaccuracies found in these sources. MAIN OUTCOME MEASURES: Numbers of induced abortions in Australia for each year from 1985 to 2003; abortion rates per 1000 women aged 15-44 years. RESULTS: Abortion numbers based on Medicare claims by private patients overestimated by 18.7% the number of abortions derived from statutory notifications in South Australia during the period 1988-89 to 1999-00. Hospital morbidity data using principal diagnosis codes relating to medical abortion overestimated statutory notifications by 2.3% (mainly because of readmissions). National statistics were adjusted for these overestimations and for the estimated 14.1% of private patients who would not have submitted Medicare claims (based on surveys of private-clinic patients in New South Wales and Victoria). The estimated Australian abortion rate increased from 17.9 per 1000 women aged 15-44 in 1985 to a peak of 21.9/1000 in 1995, then declined to 19.7/1000 in 2003 (estimated number of abortions, 84,460). CONCLUSION: There are no data currently available for deriving accurate numbers of induced abortions in Australia. Suggestions are made for collection of national statistics.     

Who's overweight? Comparison of the medical definition and community views

OBJECTIVE: To investigate the extent to which people who are medically defined as overweight perceive themselves to be overweight. DESIGN: Secondary data analysis of the National Health Survey and the National Nutrition Survey conducted by the Australian Bureau of Statistics in 1995. PARTICIPANTS: 10,652 people aged 18 years and over (5076 men, 5576 women) in a multistage cluster sample of households throughout Australia. MAIN OUTCOME MEASURES: Body mass index (BMI) based on measured height and weight; self-reported perception of body weight (underweight, acceptable weight, or overweight). RESULTS: Among people with a measured BMI > or = 25, 49.3% of men (95% CI, 48.1%-50.5%) and 72.0% of women (95% CI, 70.8%-73.1%) considered themselves overweight. Among those with a measured BMI < 25, 3.4% of men (95% CI, 2.8%-4.1%) and 12.4% of women (95% CI, 11.4%-13.3%) considered themselves overweight. Older women were less likely to perceive themselves as overweight than younger women. The lowest BMI at which at least half the respondents considered themselves overweight was 26 to < 27 for women aged 18-59 years, and 28 to < 29 for older women and men. CONCLUSION: For many people, particularly men and older women, the meaning of "overweight" differs from the medical definition. Clinical and public health weight reduction programs which do not take this into account are unlikely to be successful.     

Factors related to the presentation of patients with thick primary melanomas

OBJECTIVE: To identify any characteristics of patients that are associated with presentation with thick primary melanoma. DESIGN: This was a retrospective survey of the clinical records of 1300 patients attending the Newcastle Melanoma Unit. Characteristics of 131 patients with thick melanomas (defined as 3 mm or greater in thickness) were compared with those of 543 patients with thin melanomas (defined as 0.75 mm or less in thickness). Comparisons were made using contingency table analysis, Wilcoxon rank sum tests, log rank analysis and logistic regression. SETTING: The Newcastle Melanoma Unit is a tertiary referral centre for the treatment of primary melanoma. PATIENTS: We surveyed all 1300 patients attending the Newcastle Melanoma Unit over the years 1981-1990. They represented approximately 90% of the patients in the Hunter region of New South Wales who developed melanoma during this period. Excluded from analysis were 39 patients with occult primary melanomas, 79 with multiple primary melanomas, 51 with primary melanomas of unknown thickness and seven with incomplete records, leaving 1124 patients in the study. MAIN OUTCOME MEASURES: These were selected before the results were known. The hypothesis was generated following analysis of the data. RESULTS: Patients with thick primary melanoma were more likely to be men (68% men and 32% women in the thick melanoma group, compared with 45% and 55% respectively in the thin melanoma group, P less than 0.005) over 60 (75% were over 50 years of age in the thick group versus 33% in the thin melanoma group, P less than 0.001) with nodular melanoma (62%, versus 2% in the thin melanoma group, P less than 0.001) and with melanoma on the head and neck (27%, versus 12% in patients with thin melanoma, P less than 0.005). The time from detection of a change in skin to diagnosis was not longer for those with thick compared to those with thin melanomas. CONCLUSION: The greatest problem of those with thin melanomas. CONCLUSION: The greatest problem of detecting melanoma at an early (surgically curable) stage appears to be in patients over the age of 50 who have nodular melanoma, particularly in the head and neck.     

Impact of smoking, diabetes and hypertension on survival time in the elderly: the Dubbo Study

OBJECTIVE: To study the impact of various risk factors on survival time in a cohort of elderly Australians. DESIGN, SETTING AND PARTICIPANTS: A longitudinal, prospective cohort study conducted in Dubbo, NSW. Participants were men and women aged 60 years or over living in the community, first assessed in 1988-1989 and followed for 15 years. MAIN OUTCOME MEASURES: Mortality rates; risk factors; survival times. RESULTS: There were 668 deaths in 1233 men (54%) and 625 deaths in 1572 women (40%). Coronary heart disease was the major cause of death, rates being higher in men than women until age group 80+ years; stroke death rates were similar in both sexes; cancer and respiratory death rates were higher in men than women across all ages. In a proportional hazards model, the independent predictors of mortality were cigarette smoking, diabetes, very high blood pressure (BP), impaired peak expiratory flow (PEF), physical disability, and zero intake of alcohol. Over 15 years, the average reductions in survival time associated with various risk factors, in men and women respectively, were smoking, 22 and 15 months; diabetes, 18 and 18 months; very high BP, 16 and 9 months; impaired PEF, 14 and 17 months; physical disability, 16 and 12 months; zero alcohol intake, 9 and 5 months. Combinations of selected risk factors were associated with a multiplier effect. CONCLUSION: The reduction in survival time in elderly citizens demonstrated in the presence of smoking, diabetes and hypertension highlights a potential benefit to healthy ageing to be gained from prevention and intervention.