Tiew-Hwa Katherine Teng

Heart Failure Incidence, Case Fatality, and Hospitalization Rates in Western Australia Between 1990 and 2005

Background—We examined trends in incidence of first-ever (index) hospitalization for heart failure (HF), hospitalization rates, and 30-day and 1-year all-cause mortality subsequent to index hospitalization for HF. Methods and Results—The Western Australia Hospital Morbidity Database was used to identify a retrospective population-based cohort with an index hospitalization for HF in Western Australia between 1990 and 2005. Risk-adjusted temporal trends in mortality were examined with the use of multivariable logistic regression models. Baseline period for comparison was 1990–1993. The cohort (n=19342; mean age, 74.2±13.2 years; 51.3% men) was followed until death or end of 2006. During the period of 1990–2005, age-standardized rates (per 100 000) of index hospitalization for HF as a principal diagnosis decreased from 191.0 to 103.2 in men, with an annual decrease of 3.5%, and from 130.5 to 75.1 in women, with an annual decrease of 3.1%. Risk-adjusted odds ratio of death at 30 days decreased to 0.73 (95% CI, 0.65 to 0.81) based on nonelective admissions. Risk-adjusted odds ratio of 1-year mortality also decreased during the study period in both genders and across all age groups. The total number of HF hospitalizations increased, with nonelective admissions increasing by 14.9% (P for trend, <0.0001) during this period. However, age-standardized rates of nonelective HF hospitalizations decreased during the same period. Conclusions—During the 16-year period studied, the incidence of index hospitalization for HF in Western Australia decreased steadily in both genders. However, hospitalizations for HF as a measure of health service use increased, despite decreasing rates, partly because of an aging population and improved HF survival.Background— We examined trends in incidence of first-ever (index) hospitalization for heart failure (HF), hospitalization rates, and 30-day and 1-year all-cause mortality subsequent to index hospitalization for HF. Methods and Results— The Western Australia Hospital Morbidity Database was used to identify a retrospective population-based cohort with an index hospitalization for HF in Western Australia between 1990 and 2005. Risk-adjusted temporal trends in mortality were examined with the use of multivariable logistic regression models. Baseline period for comparison was 1990–1993. The cohort (n=19 342; mean age, 74.2±13.2 years; 51.3% men) was followed until death or end of 2006. During the period of 1990–2005, age-standardized rates (per 100 000) of index hospitalization for HF as a principal diagnosis decreased from 191.0 to 103.2 in men, with an annual decrease of 3.5%, and from 130.5 to 75.1 in women, with an annual decrease of 3.1%. Risk-adjusted odds ratio of death at 30 days decreased to 0.73 (95% CI, 0.65 to 0.81) based on nonelective admissions. Risk-adjusted odds ratio of 1-year mortality also decreased during the study period in both genders and across all age groups. The total number of HF hospitalizations increased, with nonelective admissions increasing by 14.9% ( P for trend, <0.0001) during this period. However, age-standardized rates of nonelective HF hospitalizations decreased during the same period. Conclusions— During the 16-year period studied, the incidence of index hospitalization for HF in Western Australia decreased steadily in both genders. However, hospitalizations for HF as a measure of health service use increased, despite decreasing rates, partly because of an aging population and improved HF survival. Received May 11, 2009; accepted December 24, 2009.

A validation study: how effective is the Hospital Morbidity Data as a surveillance tool for heart failure in Western Australia?

Objective: To determine the accuracy of the hospital discharge coding of heart failure (HF) in the Western Australian (WA) Hospital Morbidity Data (HMD).

Trends from 1996 to 2007 in incidence and mortality outcomes of heart failure after acute myocardial infarction: A population-based study of 20 812 patients with first acute myocardial infarction in Western Australia

Background Advances in treatment for acute myocardial infarction (AMI) are likely to have had a beneficial impact on the incidence of and deaths attributable to heart failure (HF) complicating AMI, although limited data are available to support this contention. Methods and Results Western Australian linked administrative health data were used to identify 20 812 consecutive patients, aged 40 to 84 years, without prior HF hospitalized with an index (first) AMI between 1996 and 2007. We assessed the temporal incidence of and adjusted odds ratio/hazard ratio for death associated with HF concurrent with AMI admission and within 1 year after discharge. Concurrent HF comprised 75% of incident HF cases. Between the periods 1996–1998 and 2005–2007, the prevalence of HF after AMI declined from 28.1% to 16.5%, with an adjusted odds ratio of 0.50 (95% CI, 0.44 to 0.55). The crude 28‐day case‐fatality rate for patients with concurrent HF declined marginally from 20.5% to 15.9% (P<0.05) compared with those without concurrent HF, in whom the case‐fatality rate declined from 11.0% to 4.8% (P<0.001). Concurrent HF was associated with a multivariate‐adjusted odds ratio of 2.2 for 28‐day mortality and a hazard ratio of 2.2 for 1‐year mortality in 28‐day survivors. Occurrence of HF within 90 days of the index AMI was associated with an adjusted hazard ratio of 2.7 for 1‐year mortality in 90‐day survivors. Conclusions Despite encouraging declines in the incidence of HF complicating AMI, it remains a common problem with high mortality. Increased attention to these high‐risk patients is needed given the lack of improvement in their long‐term prognosis.

Heart FailureCLINICAL PERSPECTIVE

Background—We examined trends in incidence of first-ever (index) hospitalization for heart failure (HF), hospitalization rates, and 30-day and 1-year all-cause mortality subsequent to index hospitalization for HF. Methods and Results—The Western Australia Hospital Morbidity Database was used to identify a retrospective population-based cohort with an index hospitalization for HF in Western Australia between 1990 and 2005. Risk-adjusted temporal trends in mortality were examined with the use of multivariable logistic regression models. Baseline period for comparison was 1990–1993. The cohort (n=19342; mean age, 74.2±13.2 years; 51.3% men) was followed until death or end of 2006. During the period of 1990–2005, age-standardized rates (per 100 000) of index hospitalization for HF as a principal diagnosis decreased from 191.0 to 103.2 in men, with an annual decrease of 3.5%, and from 130.5 to 75.1 in women, with an annual decrease of 3.1%. Risk-adjusted odds ratio of death at 30 days decreased to 0.73 (95% CI, 0.65 to 0.81) based on nonelective admissions. Risk-adjusted odds ratio of 1-year mortality also decreased during the study period in both genders and across all age groups. The total number of HF hospitalizations increased, with nonelective admissions increasing by 14.9% (P for trend, <0.0001) during this period. However, age-standardized rates of nonelective HF hospitalizations decreased during the same period. Conclusions—During the 16-year period studied, the incidence of index hospitalization for HF in Western Australia decreased steadily in both genders. However, hospitalizations for HF as a measure of health service use increased, despite decreasing rates, partly because of an aging population and improved HF survival.Background— We examined trends in incidence of first-ever (index) hospitalization for heart failure (HF), hospitalization rates, and 30-day and 1-year all-cause mortality subsequent to index hospitalization for HF. Methods and Results— The Western Australia Hospital Morbidity Database was used to identify a retrospective population-based cohort with an index hospitalization for HF in Western Australia between 1990 and 2005. Risk-adjusted temporal trends in mortality were examined with the use of multivariable logistic regression models. Baseline period for comparison was 1990–1993. The cohort (n=19 342; mean age, 74.2±13.2 years; 51.3% men) was followed until death or end of 2006. During the period of 1990–2005, age-standardized rates (per 100 000) of index hospitalization for HF as a principal diagnosis decreased from 191.0 to 103.2 in men, with an annual decrease of 3.5%, and from 130.5 to 75.1 in women, with an annual decrease of 3.1%. Risk-adjusted odds ratio of death at 30 days decreased to 0.73 (95% CI, 0.65 to 0.81) based on nonelective admissions. Risk-adjusted odds ratio of 1-year mortality also decreased during the study period in both genders and across all age groups. The total number of HF hospitalizations increased, with nonelective admissions increasing by 14.9% ( P for trend, <0.0001) during this period. However, age-standardized rates of nonelective HF hospitalizations decreased during the same period. Conclusions— During the 16-year period studied, the incidence of index hospitalization for HF in Western Australia decreased steadily in both genders. However, hospitalizations for HF as a measure of health service use increased, despite decreasing rates, partly because of an aging population and improved HF survival. Received May 11, 2009; accepted December 24, 2009.

A systematic review of air pollution and incidence of out-of-hospital cardiac arrest

Introduction Studies have linked air pollution with the incidence of acute coronary artery events and cardiovascular mortality but the association with out-of-hospital cardiac arrest (OHCA) is less clear. Aim To examine the association of air pollution with the occurrence of OHCA. Methods Electronic bibliographic databases (until February 2013) were searched. Search terms included common air pollutants and OHCA. Studies of patients with implantable cardioverter defibrillators and OHCA not attended by paramedics were excluded. Two independent reviewers (THKT and TAW) identified potential studies. Methodological quality was assessed by the Newcastle-Ottawa Scale. Results Of 849 studies, 8 met the selection criteria. Significant associations between particulate matter (PM) exposure (especially PM2.5) and OHCA were found in 5 studies. An increase of OHCA risk ranged from 2.4% to 7% per interquartile increase in average PM exposure on the same day and up to 4 days prior to the event. A large study found ozone increased the risk of OHCA within 3 h prior to the event. The strongest risk OR of 3.8–4.6% per 20 parts per billion ozone increase of the average level was within 2 h prior to the event. Similarly, another study found an increased risk of 18% within 2 days prior to the event. Conclusions Larger studies have suggested an increased risk of OHCA with air pollution exposure from PM2.5 and ozone.

Trends in long-term cardiovascular mortality and morbidity in men and women with heart failure of ischemic versus non-ischemic aetiology in Western Australia between 1990 and 2005.

BACKGROUND It is uncertain if improvements in long-term cardiovascular (CV) mortality have occurred in both men and women with ischemic and non-ischemic forms of heart failure (HF). METHODS The Western Australia Hospital Morbidity Database was used to identify all index (first-ever) hospitalizations for HF between 1990 and 2005. Patients were followed until death attributed to cardiovascular causes or censored on December 31, 2006 to determine 5-year survival. Cox proportional hazards models were used to compare the adjusted mortality hazard ratio (HR) during the study follow-up (4-year periods). RESULTS A total of 21,507 patients (mean age 73.9 years, 49.1% women) were identified. Women were significantly older than men, and less likely to have ischemic HF (38.8% versus 46.1%). Over the period, age-standardized incidence of first HF hospitalization declined but with the least decline in women with non-ischemic HF (-13.3%) compared to other subgroups. Risk-adjusted 5-year CV mortality declined over the study period, with HR 0.64 (95% CI 0.60-0.68) for patients admitted in 1998-2001 compared to 1990-1993, with significant improvement in both forms of HF, and in both sexes and across age groups. However, overall total HF hospitalizations increased (+26.7%) over the period, particularly for non-ischemic HF (+43.7%), of which elderly women formed the predominant group. CONCLUSIONS Risk-adjusted long-term survival improved similarly in men and women, including the elderly, with ischemic and non-ischemic forms of HF during 1990-2005 in Western Australia. However, there was a growing burden of HF hospitalizations particularly for HF of non-ischemic aetiology.

A comprehensive population‐based characterization of heart failure with mid‐range ejection fraction

Clinical features and outcomes in the novel phenotype heart failure with mid‐range ejection fraction [HFmrEF, ejection fraction (EF) 40–49%] were compared with heart failure with reduced EF (HFrEF, EF <40%) and preserved EF (HFpEF, EF ≥50%).

Incidence of first heart failure hospitalisation and mortality in Aboriginal and non-Aboriginal patients in Western Australia, 2000–2009

OBJECTIVES To compare the incidence of first heart failure (HF) hospitalisation, antecedent risk factors and 1-year mortality between Aboriginal and non-Aboriginal populations in Western Australia (2000-2009). METHODS A population-based cohort aged 20-84 years comprising Aboriginal (n=1013; mean 54±14 years) and non-Aboriginal patients (n=16,366; mean 71±11 years) with first HF hospitalisation was evaluated. Age and sex-specific incidence rates and HF antecedents were compared between subpopulations. Regression models were used to examine 30-day and 1-year (in 30-day survivors) mortality. RESULTS Aboriginal patients were younger, more likely to reside in rural/remote areas (76% vs 23%) and to be women (50.6% vs 41.7%, all p<0.001). Aboriginal (versus non-Aboriginal) HF incidence rates were 11-fold higher in men and 23-fold in women aged 20-39 years, declining to about 2-fold in patients aged 70-84 years. Ischaemic and rheumatic heart diseases were more common antecedents of HF in younger (<55 years) Aboriginal versus non-Aboriginal patients (p<0.001). Hypertension, diabetes, chronic kidney disease, renal failure, chronic obstructive pulmonary disease, and a high Charlson comorbidity index (>=3) were also more prevalent in younger and older Aboriginal patients (p<0.001). Although 30-day mortality was similar in both subpopulations, Aboriginal patients aged<55 years had a 1.9 risk-adjusted hazard ratio (HR) for 1-year mortality (p=0.015). CONCLUSIONS Aboriginal people had substantially higher age and sex-specific HF incidence rate and prevalence of HF antecedents than their non-Aboriginal counterparts. HR for 1-year mortality was also significantly worse at younger ages, highlighting the urgent need for enhanced primary and secondary prevention of HF in this population.

Rural–urban differentials in 30-day and 1-year mortality following first-ever heart failure hospitalisation in Western Australia: a population-based study using data linkage

Objectives We examined differentials in short-term (30-day mortality) and 1-year mortality (in 30-day survivors) following index (first-ever) hospitalisation for heart failure (HF), between rural and metropolitan patients resident in Western Australia. Design A population-based cohort study. Setting Hospitalised patients in Western Australia, Australia. Participants Index patients aged 20–84 years with a first-ever hospitalisation for HF between 2000 and 2009 (with no prior admissions for HF in previous 10 years), identified using the Western Australia linked health data. Main outcome measures 30-day and 1-year all-cause mortality (in 30-day survivors) following index admission for HF. Results Of 17 379 index patients with HF identified, 25.9% (4499) were from rural areas. Rural patients were significantly younger at first HF hospitalisation than metropolitan patients. Aboriginal patients comprised 1.9% of metropolitan and 17.2% of rural patients. Despite some statistical differences, the prevalence of antecedents including ischaemic heart disease, hypertension, diabetes and chronic kidney disease was high (>20%) in both subpopulations. After adjusting for age only, patients from rural areas had a higher risk of 30-day death (OR 1.16 (95% CI 1.01 to 1.33)) and 1-year death in 30-day survivors (HR 1.11 (95% CI 1.01 to 1.23)). These relative risk estimates increased and remained significant after further progressive adjustments for Aboriginality, socioeconomic status, insurance status, emergency presentation, individual comorbidities and revascularisation with OR 1.25 (1.06 to 1.48) for 30-day mortality and HR 1.13 (1.02 to 1.27) for 1-year mortality. The addition of the weighted Charlson index to the 30-day model improved the ‘c’ statistic (under the receiver operating characteristic curve) from 0.656 (using a variation of administrative claims model) to 0.714. Conclusions Remoteness and variable access to healthcare can cause important disparities in health outcomes. Rural patients with HF in Western Australia have poorer risk-adjusted outcomes compared with metropolitan patients. This finding has important implications for chronic disease management and provision of health services in rural Australia.

Initial hospitalisation for atrial fibrillation in Aboriginal and non-Aboriginal populations in Western Australia

Objective The epidemiology of atrial fibrillation (AF) among Aboriginal Australians is poorly described. We compared risk factors, incidence rates and mortality outcomes for first-ever hospitalised AF among Aboriginal and non-Aboriginal Western Australians 20–84 years. Methods This retrospective cohort study used whole-of-state person-based linked hospital and deaths data. Incident hospital AF admissions (previous AF admission-free for 15 years) were identified and subsequent mortality determined. Disease-specific comorbidity histories were ascertained by 10-year look-back. Age-standardised incidence rates were estimated and the adjusted risk of 30-day and 1-year mortality calculated using regression methods. Results Aboriginal patients accounted for 923 (2.5%) of 37 097 incident AF admissions during 2000–2009. Aboriginal patients were younger (mean age 54.8 vs 69.3 years), had lower proportions of primary field AF diagnoses and higher comorbidities than non-Aboriginal patients. The Aboriginal and non-Aboriginal age-standardised incidence rates per 100 000 for men 20–54 years were 197 and 55 (ratio=3.6), for women 20–54 years were 122 and 19 (ratio=6.4), for men 55–84 years were 1151 and 888 (ratio=1.3), and for women 55–84 years were 1050 and 571 (ratio=1.8). While 30-day mortality was similar, crude 1-year mortality risks in Aboriginal and non-Aboriginal patients were 20.6% and 16.3% (adjusted HR=1.24) and 14.4% and 9.9% in 30-day survivors (adjusted HR=1.58). Conclusions The incidence (particularly at young ages) and long-term mortality following hospitalised AF is significantly higher in Aboriginal people. Better control of the antecedent risk factors for AF, improved detection and management of AF itself and prevention of its complications are needed.