Excess Deaths Associated with Rheumatic Heart Disease, Australia, 2013-2017.

During 2013-2017, the mortality rate ratio for rheumatic heart disease among Indigenous versus non-Indigenous persons in Australia was 15.9, reflecting health inequity. Using excess mortality methods, we found that deaths associated with rheumatic heart disease among Indigenous Australians were probably substantially undercounted, affecting accuracy of calculations based solely on Australian Bureau of Statistics data.

First stroke incidence, causes, treatments, and outcomes for Aboriginal Peoples in South Australia and the Northern Territory: a pilot prospective study.

OBJECTIVE: We performed a pilot stroke incidence study, focused on feasibility and inclusion of the CONSIDER reporting guidelines, to model the design of a future population-based study aiming to definitively determine stroke incidence, antecedents, treatment, and outcomes. STUDY DESIGN: Prospective stroke incidence study (pilot study). SETTING, PARTICIPANTS: All people aged 15 years or older who lived in postcode-defined areas of South Australia and Northern Territory (885 472 people, including 45 127 Aboriginal people [5.1%]) diagnosed with stroke for the first time during 1 October - 31 December 2015 and admitted to public hospitals or stroke and transient ischaemic attack clinics. MAIN OUTCOME MEASURES: Feasibility of a prospective population-based stroke incidence study. RESULTS: Of the 123 participants with first strokes, ten were Aboriginal (8%); the median age of Aboriginal people was 45 years (interquartile range [IQR], 33-55 years), of non-Indigenous people 73 years (IQR, 62-84 years). For Aboriginal people, the age-standardised incidence of stroke was 104 (95% confidence interval [CI], 84-124) per 100 000 person-years, for non-Indigenous people 33 (95% CI, 22-44) per 100 000 person-years. We found that a prospective population-based stroke incidence study in Aboriginal people was feasible, including with respect to establishing an adequate sample size, diagnostic confirmation, identification of incident stroke, confirming stroke subtypes, establishing a stable statistical population, standardising data reporting for comparison with other stroke incidence studies, and ethical research reporting that conforms to CONSIDER guidelines. CONCLUSIONS: A larger, population-based study of the incidence of stroke in Aboriginal people is both feasible and needed to provide robust estimates of stroke incidence, antecedents, treatments and outcomes to help guide strategies for reducing the risk of and outcomes of stroke in Aboriginal people.

Determining the Optimal Methodology for Identifying Incident Stroke Deaths Using Administrative Datasets Within Australia.

BACKGROUND AND AIM: Quantifying stroke incidence and mortality is crucial for disease surveillance and health system planning. Administrative data offer a cost-effective alternative to "gold standard" population-based studies. However, the optimal methodology for establishing stroke deaths from administrative data remains unclear. We aimed to determine the optimal method for identifying stroke-related deaths in administrative datasets as the fatal component of stroke incidence, comparing counts derived using underlying and all causes of death (CoD). METHOD: Using whole-population multijurisdictional person-level linked data from hospital and death datasets from South Australia, the Northern Territory, and Western Australia, we identified first-ever stroke events between 2012 and 2015, using underlying CoD and all CoD to identify fatal stroke counts. We determined the 28-day case fatality for both counts and compared results with gold standard Australian population-based stroke incidence studies. RESULTS: The total number of incident stroke events was 16,150 using underlying CoD and 18,074 using all CoD. Case fatality was 24.7% and 32.7% using underlying and all CoD, respectively. Case fatality using underlying CoD was similar to that observed in four Australian "gold standard" population-based studies (20%-24%). CONCLUSIONS: Underlying CoD generates fatal incident stroke estimates more consistent with population-based studies than estimates based on stroke deaths identified from all-cause fields in death registers.

Intersectionality and Its Relevance in the Context of Aboriginal People with Brain Injury in Australia.

In this article, we explore the benefits of recognizing the impact of intersectionality on access to, and provision of, brain injury care in a First Nations context. While disadvantage and discrimination are often associated with the intersection of culture, gender, disability, and socioeconomic disadvantage, it is only when these factors are explored together that clinicians can really understand what people need to recover and thrive following acquired brain injury. In this article, we challenge speech-language pathologists to examine their own practices, to look beyond Western models of health and constraints of many current institutional models of care and ways of framing research, to acknowledge historical and ongoing colonizing influences, and to engage with community-led solutions. We provide a model of Aboriginal-led care, where intersection of discrimination and marginalization is minimized and the multiple components of the individual, carers/communication partners, and the environment become empowering factors instead.

Incidence of Stroke in the Aboriginal and Non-Aboriginal Populations of Australia: A Data Linkage Study.

BACKGROUND: Most estimates of stroke incidence among Aboriginal and Torres Strait Islander (hereinafter Aboriginal) Australians are confined to single regions and include small sample sizes. We aimed to measure and compare stroke incidence in Aboriginal and non-Aboriginal residents across central and western Australia. METHODS: Whole-population multijurisdictional person-linked data from hospital and death datasets were used to identify stroke admissions and stroke-related deaths (2001-2015) in Western Australia, South Australia, and the Northern Territory. Fatal (including out-of-hospital deaths) and nonfatal incident (first-ever) strokes in patients aged 20-84 years were identified during the 4-year study period (2012-2015), using a 10-year lookback period to exclude people with prior stroke. Incidence rates per 100 000 population/year were estimated for Aboriginal and non-Aboriginal populations, age-standardized to the World Health Organization World Standard population. RESULTS: In a population of 3 223 711 people (3.7% Aboriginal), 11 740 incident (first-ever) strokes (20.6% regional/remote location of residence; 15.6% fatal) were identified from 2012 to 2015, 675 (5.7%) in Aboriginal people (73.6% regional/remote; 17.0% fatal). Median age of Aboriginal cases (54.5 years; 50.1% female) was 16 years younger than non-Aboriginal cases (70.3 years; 44.1% female; P<0.001), with significantly greater prevalence of comorbidities. Age-standardized stroke incidence in Aboriginal people (192/100 000 [95% CI, 177-208]) was 2.9-fold greater than in non-Aboriginal people (66/100 000 [95% CI, 65-68]) aged 20-84 years; fatal incidence was 4.2-fold greater (38/100 000 [95% CI, 31-46] versus 9/100 000 [95% CI, 9-10]). Disparities were particularly apparent at younger ages (20-54 years), where age-standardized stroke incidence was 4.3-fold greater in Aboriginal people (90/100 000 [95% CI, 81-100]) than non-Aboriginal people (21/100 000 [95% CI, 20-22]). CONCLUSIONS: Stroke occurred more commonly, and at younger ages, in Aboriginal than non-Aboriginal populations. Greater prevalence of baseline comorbidities was present in the younger Aboriginal population. Improved primary prevention is required. To optimize stroke prevention, interventions should include culturally appropriate community-based health promotion and integrated support for nonmetropolitan health services.

Fracture Risk Increases After Stroke or Transient Ischemic Attack and Is Associated With Reduced Quality of Life.

BACKGROUND: Fractures are a serious consequence following stroke, but it is unclear how these events influence health-related quality of life (HRQoL). We aimed to compare annualized rates of fractures before and after stroke or transient ischemic attack (TIA), identify associated factors, and examine the relationship with HRQoL after stroke/TIA. METHODS: Retrospective cohort study using data from the Australian Stroke Clinical Registry (2009-2013) linked with hospital administrative and mortality data. Rates of fractures were assessed in the 1-year period before and after stroke/TIA. Negative binomial regression, with censoring at death, was used to identify factors associated with fractures after stroke/TIA. Respondents provided HRQoL data once between 90 and 180 days after stroke/TIA using the EuroQoL 5-dimensional 3-level instrument. Adjusted logistic regression was used to assess differences in HRQoL at 90 to 180 days by previous fracture. RESULTS: Among 13 594 adult survivors of stroke/TIA (49.7% aged ≥75 years, 45.5% female, 47.9% unable to walk on admission), 618 fractures occurred in the year before stroke/TIA (45 fractures per 1000 person-years) compared with 888 fractures in the year after stroke/TIA (74 fractures per 1000 person-years). This represented a relative increase of 63% (95% CI, 47%-80%). Factors associated with poststroke fractures included being female (incidence rate ratio [IRR], 1.34 [95% CI, 1.05-1.72]), increased age (per 10-year increase, IRR, 1.35 [95% CI, 1.21-1.50]), history of prior fracture(s; IRR, 2.56 [95% CI, 1.77-3.70]), and higher Charlson Comorbidity Scores (per 1-point increase, IRR, 1.18 [95% CI, 1.10-1.27]). Receipt of stroke unit care was associated with fewer poststroke fractures (IRR, 0.67 [95% CI, 0.49-0.93]). HRQoL at 90 to 180 days was worse among patients with prior fracture across the domains of mobility, self-care, usual activities, and pain/discomfort. CONCLUSIONS: Fracture risk increases substantially after stroke/TIA, and a history of these events is associated with poorer HRQoL at 90 to 180 days after stroke/TIA.

Differing Definitions of First-Ever Stroke Influence Incidence Estimates More than Trends: A Study Using Linked Administrative Data.

INTRODUCTION: Researchers apply varying definitions when measuring stroke incidence using administrative data. We aimed to investigate the sensitivity of incidence estimates to varying definitions of stroke and lookback periods and to provide updated incidence rates and trends for Western Australia (WA). METHODS: We used linked state-wide hospital and death data from 1985 to 2017 to identify incident strokes from 2005 to 2017. A standard definition was applied which included strokes coded as the principal hospital diagnosis or the underlying cause of death, with a 10-year lookback used to clear prevalent cases. Alternative definitions were compared against the standard definition by percentage difference in case numbers. Age-standardised incidence rates were calculated, and age- and sex-adjusted Poisson regression models were used to estimate incidence trends. RESULTS: The standard definition with a 10-year lookback period captured 31,274 incident strokes. Capture increased by 19.3% when including secondary diagnoses, 4.1% when including nontraumatic subdural and extradural haemorrhage, and 8.1% when including associated causes of death. Excluding death records reduced capture by 11.1%. A 20-year lookback reduced over-ascertainment by 2.0%, and a 1-year lookback increased capture by 13.3%. Incidence declined 0.6% annually (95% confidence interval -0.9, -0.3). Annual reductions were similar for most definitions except when death records were excluded (-0.1%, CI: -0.4, 0.2) and with the shortest lookback periods (greatest annual reduction). CONCLUSION: Stroke incidence has declined in WA. Differing methods of identifying stroke influence estimates of incidence to a greater extent than estimates of trends. Reductions in stroke incidence over time are primarily driven by declines in fatal strokes.

Left ventricular remodelling in rheumatic heart disease - trends over time and implications for follow-up in childhood.

BACKGROUND: Rheumatic heart disease (RHD) is the most common form of acquired heart disease worldwide. In RHD, volume loading from mitral regurgitation leads to left ventricular (LV) dilatation, increased wall stress, and ultimately LV dysfunction. Improved understanding of LV dynamics may contribute to refined timing of intervention. We aimed to characterize and compare left ventricular remodelling between rheumatic heart disease (RHD) severity groups by way of serial echocardiographic assessment of volumes and function in children. METHODS: Children with RHD referred to Perth Children's Hospital (formally Princess Margaret Hospital) (1987-2020) were reviewed. Patients with longitudinal pre-operative echocardiograms at diagnosis, approximately 12 months and at most recent follow-up, were included and stratified into RHD severity groups. Left ventricular (LV) echocardiographic parameters were assessed. Adjusted linear mixed effect models were used to compare interval changes. RESULTS: 146 patients (median age 10 years, IQR 6-14 years) with available longitudinal echocardiograms were analysed. Eighty-five (58.2%) patients had mild, 33 (22.6%) moderate and 28 (19.2%) severe RHD at diagnosis. Mean duration of follow-up was 4.6 years from the initial diagnosis. Severe RHD patients had significantly increased end-systolic volumes (ESV) and end-diastolic volumes (EDV) compared to mild/moderate groups at diagnosis (severe versus mild EDV mean difference 27.05 ml/m2, p < 0.001, severe versus moderate EDV mean difference 14.95 ml/m2, p = 0.006). Mild and moderate groups experienced no significant progression of changes in volume measures. In severe RHD, LV dilatation worsened over time. All groups had preserved cardiac function. CONCLUSIONS: In mild and moderate RHD, the lack of progression of valvular regurgitation and ventricular dimensions suggest a stable longer-term course. Significant LV remodelling occurred at baseline in severe RHD with progression of LV dilatation over time. LV function was preserved across all groups. Our findings may guide clinicians in deciding the frequency and timing of follow-up and may be of clinical utility during further reiterations of the Australia and New Zealand RHD Guidelines.

A Review of Cardiac Surgical Procedures and Their Outcomes for Paediatric Rheumatic Heart Disease in Western Australia.

INTRODUCTION: Surgical intervention is an important treatment modality for advanced rheumatic heart disease (RHD). This study aimed to describe patient characteristics and outcomes from cardiac surgery for RHD in patients referred to the only tertiary paediatric hospital in Western Australia. METHODS: An analysis of patient characteristics and cardiac surgery outcomes in patients with RHD was undertaken, using data from clinical cardiac databases, medical notes, and correspondence from rural outreach clinics. RESULTS: 29 patients (59% female, 97% Aboriginal, Maori or Pacific Islander) underwent 41 valve interventions over 34 cardiac surgeries for RHD between 2000-2018. Median age at first surgery was 12.2 (range 4-16) years. Severe mitral regurgitation (MR) was the most common indication for primary surgery (62%), followed by mixed mitral regurgitation/aortic regurgitation (21%) and severe aortic regurgitation (17%). Mitral valve repair was the most common valve intervention (56%). Two patients had mitral valve replacement (MVR) at first operation, two patients had MVR at second operation and two had MVR at third operation. There was no early mortality. One patient required early (<30 days) reoperation for aortic valve repair failure. Two patients had late reoperations at 3.3 and 6.1 months after the first procedure for MR. Four (14%) patients experienced documented ARF recurrences. Late mortality occurred in 3 (10%) patients, all due to cardiac causes. On last follow-up echocardiogram 5 patients (17%) had moderate MR and none had severe MR. CONCLUSIONS: This is the first study to describe characteristics and outcomes in WA paediatric patients having surgery for RHD. Outcomes are comparable to similar studies, with favourable long-term survival.

The Allure of Big Data to Improve Stroke Outcomes: Review of Current Literature.

PURPOSE OF REVIEW: To critically appraise literature on recent advances and methods using "big data" to evaluate stroke outcomes and associated factors. RECENT FINDINGS: Recent big data studies provided new evidence on the incidence of stroke outcomes, and important emerging predictors of these outcomes. Main highlights included the identification of COVID-19 infection and exposure to a low-dose particulate matter as emerging predictors of mortality post-stroke. Demographic (age, sex) and geographical (rural vs. urban) disparities in outcomes were also identified. There was a surge in methodological (e.g., machine learning and validation) studies aimed at maximizing the efficiency of big data for improving the prediction of stroke outcomes. However, considerable delays remain between data generation and publication. Big data are driving rapid innovations in research of stroke outcomes, generating novel evidence for bridging practice gaps. Opportunity exists to harness big data to drive real-time improvements in stroke outcomes.

Can the CHA2 DS2 -VA schema be used to decide on anticoagulant therapy in Aboriginal and other Australians with non-valvular atrial fibrillation?

The Australasian guidelines recommend use of the CHA2 DS2 -VA schema to stratify ischaemic stroke risk in patients with non-valvular atrial fibrillation (N-VAF) and determine risk thresholds for recommending oral anticoagulant (OAC) therapy. However, the CHA2 DS2 -VA score has not been validated in a representative Australian population cohort with N-VAF, including in Aboriginal people who are known to have a higher age-adjusted stroke risk than other Australians. In a retrospective data-linkage study of 49 114 patients aged 24-84 years with N-VAF, 40.0% women and 2.5% Aboriginal, we found that patients with a CHA2 DS2 -VA score >2 had high annual stroke rates (>2%) that would justify OAC therapy. This occurred regardless of Aboriginal status. Non-Aboriginal patients with a CHA2 DS2 -VA score of 0 had a mean annual stroke rate of 0.4%, and hence were not likely to benefit from antithrombotic therapy. However, Aboriginal patients with a zero CHA2 DS2 -VA score had a significantly higher annual stroke rate of 0.9%, and could potentially obtain net clinical benefit from anticoagulation, primarily with the safer non-vitamin K antagonist OAC. We conclude that clinicians can confidently use the CHA2 DS2 -VA score to make decisions regarding anticoagulation in accordance with stroke risk in patients with N-VAF, except in Aboriginal people in whom the risk score was unable to identify those at truly low risk of stroke.

Hospital Presentations in Long-Term Survivors of Stroke: Causes and Associated Factors in a Linked Data Study.

BACKGROUND AND PURPOSE: A comprehensive understanding of the long-term impact of stroke assists in health care planning. We aimed to determine changes in rates, causes, and associated factors for hospital presentations among long-term survivors of stroke. METHODS: Person-level data from the AuSCR (Australian Stroke Clinical Registry) during 2009 to 2013 were linked with state-based health department emergency department and hospital admission data. The study cohort included adults with first-ever stroke who survived the first 6 months after discharge from hospital. Annualized rates of hospital presentations (nonadmitted emergency department or admission)/person/year were calculated for 1 to 12 months prior, and 7 to 12 months (inclusive) after hospitalization. Multilevel, negative binomial regression was used to identify associated factors after adjustment for prestroke hospital presentations and stratification for perceived impairment status. Perceived impairments to health were defined according to the subscales and visual analog health status scores on the 5-Dimension European Quality of Life Scale. RESULTS: There were 7183 adults with acute stroke, 7-month survivors (median age 72 years; 56% male; 81% ischemic, and 42% with impairment at 90-180 days) from 39 hospitals included in this landmark analysis. Annualized presentations/person increased from 0.88 (95% CI, 0.86-0.91) to 1.25 (95% CI, 1.22-1.29) between the prestroke and poststroke periods, with greater rate increases in those with than without perceived impairment (55% versus 26%). Higher presentation rates were most strongly associated with older age (≥85 versus 65 years, incidence rate ratio, 1.52 [95% CI, 1.27-1.82]) and greater comorbidity score (incidence rate ratio, 1.06 [95% CI, 1.02-1.10]), whereas reduced rates were associated with greater social advantage (incidence rate ratio, 0.71 [95% CI, 0.60-0.84]). Poststroke hospital presentations (7-12 months) were most frequently related to recurrent cardiovascular and cerebrovascular events and sequelae of stroke. CONCLUSIONS: A large increase in annualized hospital presentation rates after stroke indicates the potential for improved community management and support for this vulnerable patient group.

Factors Associated With 90-Day Readmission After Stroke or Transient Ischemic Attack: Linked Data From the Australian Stroke Clinical Registry.

Background and Purpose- Readmissions after stroke are common and appear to be associated with comorbidities or disability-related characteristics. In this study, we aimed to determine the patient and health-system level factors associated with all-cause and unplanned hospital readmission within 90 days after acute stroke or transient ischemic attack (TIA) in Australia. Methods- We used person-level linkages between data from the Australian Stroke Clinical Registry (2009-2013), hospital admissions data and national death registrations from 4 Australian states. Time to first readmission (all-cause or unplanned) for discharged patients was examined within 30, 90, and 365 days, using competing risks regression to account for deaths postdischarge. Covariates included age, stroke severity (ability to walk on admission), stroke type, admissions before stroke/TIA and the Charlson Comorbidity Index (derived from International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, [Australian modified] coded hospital data in the preceding 5 years). Results- Among the 13 594 patients discharged following stroke/TIA (45% female; 65% ischemic stroke; 11% intracerebral hemorrhage; 4% undetermined stroke; and 20% TIA), 25% had an all-cause readmission and 15% had an unplanned readmission within 90 days. In multivariable analyses, the factors independently associated with a greater risk of unplanned readmission within 90 days were being female (subhazard ratio, 1.13 [95% CI, 1.03-1.24]), greater Charlson Comorbidity Index scores (subhazard ratio, 1.11 [95% CI, 1.09-1.12]) and having an admission ≤90 days before the index event (subhazard ratio, 1.85 [95% CI, 1.59-2.15]). Compared with being discharged to rehabilitation or aged care, those who were discharged directly home were more likely to have an unplanned readmission within 90 days (subhazard ratio, 1.44 [95% CI, 1.33-1.55]). These factors were similar for readmissions within 30 and 365 days. Conclusions- Apart from comorbidities and patient-level characteristics, readmissions after stroke/TIA were associated with discharge destination. Greater support for transition to home after stroke/TIA may be needed to reduce unplanned readmissions.

Differences in stroke risk and cardiovascular mortality for Aboriginal and other Australian patients with atrial fibrillation.

OBJECTIVES: To assess the risks of stroke and cardiovascular mortality for Aboriginal and non-Aboriginal Australians with atrial fibrillation. DESIGN: Retrospective data linkage cohort study. SETTING, PARTICIPANTS: All people aged 20-84 years hospitalised with atrial fibrillation in Western Australia during 2000-2012. MAIN OUTCOME MEASURES: Stroke incidence rates and mortality after hospitalisation for atrial fibrillation, and 10-year risks of stroke and of cardiovascular and all-cause mortality. RESULTS: Among 55 482 index admissions with atrial fibrillation, 7.7% of 20-59-year-old patients and 1.3% of 60-84-year-old patients were Aboriginal Australians. A larger proportion of Aboriginal patients aged 20-59 years had CHA2 DS2 -VASc scores of 2 or more (59.8% v 21.8%). In 20-59-year-old Aboriginal patients, the incidence during follow-up (maximum, 10 years; median, 7.1 years) of stroke (incidence rate ratio [IRR], 3.2; 95% CI, 2.5-4.1) and fatal stroke (IRR, 5.7; 95% CI, 3.9-8.9) were markedly higher than for non-Aboriginal patients. Stroke incidence was higher for 60-84-year-old patients, but the difference between Aboriginal and non-Aboriginal patients was smaller (IRR, 1.6; 95% CI, 1.3-2.0). Cardiovascular mortality during follow-up was also higher for 20-59-year-old Aboriginal patients (IRR, 4.4; 95% CI, 4.3-5.9). The hazards of stroke (adjusted HR [aHR], 1.67; 95% CI, 1.22-2.28) and cardiovascular mortality (aHR, 1.47; 95% CI, 1.18-1.83) in younger Aboriginal patients remained significantly higher after multivariable adjustment; age/sex, principal diagnosis of atrial fibrillation, and CHA2 DS2 -VASc score were the most influential factors. CONCLUSION: Stroke risk and cardiovascular mortality are markedly higher for Aboriginal than non-Aboriginal patients with atrial fibrillation, particularly for patients under 60. Strategies for providing evidence-based therapies and cardiovascular prevention to Aboriginal people with atrial fibrillation must be improved.

Ending rheumatic heart disease in Australia: the evidence for a new approach.

■The RHD Endgame Strategy: the blueprint to eliminate rheumatic heart disease in Australia by 2031 (the Endgame Strategy) is the blueprint to eliminate rheumatic heart disease (RHD) in Australia by 2031. Aboriginal and Torres Strait Islander people live with one of the highest per capita burdens of RHD in the world. ■The Endgame Strategy synthesises information compiled across the 5-year lifespan of the End Rheumatic Heart Disease Centre of Research Excellence (END RHD CRE). Data and results from priority research projects across several disciplines of research complemented literature reviews, systematic reviews and narrative reviews. Further, the experiences of those working in acute rheumatic fever (ARF) and RHD control and those living with RHD to provide the technical evidence for eliminating RHD in Australia were included. ■The lived experience of RHD is a critical factor in health outcomes. All future strategies to address ARF and RHD must prioritise Aboriginal and Torres Strait Islander people's knowledge, perspectives and experiences and develop co-designed approaches to RHD elimination. The environmental, economic, social and political context of RHD in Australia is inexorably linked to ending the disease. ■Statistical modelling undertaken in 2019 looked at the economic and health impacts of implementing an indicative strategy to eliminate RHD by 2031. Beginning in 2019, the strategy would include: reducing household crowding, improving hygiene infrastructure, strengthening primary health care and improving secondary prophylaxis. It was estimated that the strategy would prevent 663 deaths and save the health care system $188 million. ■The Endgame Strategy provides the evidence for a new approach to RHD elimination. It proposes an implementation framework of five priority action areas. These focus on strategies to prevent new cases of ARF and RHD early in the causal pathway from Streptococcus pyogenes exposure to ARF, and strategies that address the critical systems and structural changes needed to support a comprehensive RHD elimination strategy.

Rheumatic heart disease in pregnancy: Profile of women admitted to a Western Australian tertiary obstetric hospital.

This retrospective study assessed maternal and perinatal outcomes for women with rheumatic heart disease (RHD) admitted to the largest tertiary obstetric hospital in Western Australia from 2009 to 2016. Of 54 women identified, 75.9% were Indigenous, 59.3% lived in rural areas and 40.7% had severe RHD. Heart failure developed in 10% who gave birth. Indigenous women were younger, had higher gravidity (P = 0.0305), were more likely to receive secondary prophylaxis (P = 0.0041) and have sub-optimal antenatal clinic attendance (P = 0.0078). There were no maternal deaths and two perinatal deaths (4.0%), reflecting vigilance in the obstetric management of women with RHD in Western Australia.

A Validation Study: How Predictive Is a Diagnostic Coding Algorithm at Identifying Rheumatic Heart Disease in Western Australian Hospital Data?

BACKGROUND: International Classification of Diseases codes for rheumatic heart disease (RHD) (ICD-10 I05-I08) include valvular heart disease of unspecified origin, limiting their usefulness for estimating RHD burden. An expert opinion-based algorithm was developed to increase their accuracy for epidemiological case ascertainment. The algorithm included codes not defaulting to RHD ('probable') plus selected codes pertaining to mitral valve involvement in patients <60 years ('possible'). We aimed to determine the positive predictive value (PPV) for RHD of algorithm-selected hospital admissions. METHODS: Chart reviews of RHD-coded admissions (n=368) to Western Australian tertiary hospitals (2009-2016) authenticated RHD diagnosis. We selected all cases with algorithm-positive codes from populations at high-risk of RHD and an age-stratified random sample from low-risk groups. RHD status was determined from echocardiographic reports or clinical diagnosis in charts. PPVs were compared by population risk status (high-risk/low-risk), age group, gender, principal/secondary diagnosis and probable/possible codes. RESULTS: High-risk patients had higher PPVs than low-risk patients (83.8% vs 54.9%, p<0.0001). PPVs were 91.5% and 51.5% respectively for algorithm-defined 'probable RHD' and 'possible' codes (p<0.0001). The PPVs in low-risk patients were higher for principal diagnoses than secondary diagnoses (84.5% vs 44.8%, weighted p<0.0001) but were similar in high-risk patients (92.5% vs 81.7%, p=0.096). CONCLUSION: The algorithm performs well for RHD coded as a principal diagnosis, 'probable' codes or in populations at high risk of RHD. Refinement is needed for identifying true RHD in low-risk groups.

Disparities in Antihypertensive Prescribing After Stroke: Linked Data From the Australian Stroke Clinical Registry.

Background and Purpose- Despite evidence to support the prescription of antihypertensive medications before hospital discharge to promote medication adherence and prevent recurrent events, many patients with stroke miss out on these medications at discharge. We aimed to examine patient, clinical, and system-level differences in the prescription of antihypertensive medications at hospital discharge after stroke. Methods- Adults with acute ischemic stroke or intracerebral hemorrhage alive at discharge were included (years 2009-2013) from 39 hospitals participating in the Australian Stroke Clinical Registry. Patient comorbidities were identified using the International Statistical Classification of Diseases and Related Health Problems (Tenth Edition, Australian Modification) codes from the hospital admissions and emergency presentation data. The outcome variable and other system factors were derived from the Australian Stroke Clinical Registry dataset. Multivariable, multilevel logistic regression was used to examine factors associated with the prescription of antihypertensive medications at hospital discharge. Results- Of the 10 315 patients included, 79.0% (intracerebral hemorrhage, 74.1%; acute ischemic stroke, 79.8%) were prescribed antihypertensive medications at discharge. Prescription varied between hospital sites, with 6 sites >2 SDs below the national average for provision of antihypertensives at discharge. Prescription was also independently associated with patient and clinical factors including history of hypertension, diabetes mellitus, management in an acute stroke unit, and discharge to rehabilitation. In patients with acute ischemic stroke, females (odds ratio, 0.85; 95% CI, 0.76-0.94), those who had greater stroke severity (odds ratio, 0.81; 95% CI 0.72-0.92), or dementia (odds ratio, 0.65; 95% CI, 0.52-0.81) were less likely to be prescribed. Conclusions- Prescription of antihypertensive medications poststroke varies between hospitals and according to patient factors including age, sex, stroke severity, and comorbidity profile. Implementation of targeted quality improvement initiatives at local hospitals may help to reduce the variation in prescription observed.

Maximising data value and avoiding data waste: a validation study in stroke research.

OBJECTIVES: To determine the feasibility of linking data from the Australian Stroke Clinical Registry (AuSCR), the National Death Index (NDI), and state-managed databases for hospital admissions and emergency presentations; to evaluate data completeness and concordance between datasets for common variables. DESIGN, SETTING, PARTICIPANTS: Cohort design; probabilistic/deterministic data linkage of merged records for patients treated in hospital for stroke or transient ischaemic attack from New South Wales, Queensland, Victoria, and Western Australia. MAIN OUTCOME MEASURES: Descriptive statistics for data matching success; concordance of demographic variables common to linked databases; sensitivity and specificity of AuSCR in-hospital death data for predicting NDI registrations. RESULTS: Data for 16 214 patients registered in the AuSCR during 2009-2013 were linked with one or more state datasets: 15 482 matches (95%) with hospital admissions data, and 12 902 matches (80%) with emergency department presentations data were made. Concordance of AuSCR and hospital admissions data exceeded 99% for sex, age, in-hospital death (each κ = 0.99), and Indigenous status (κ = 0.83). Of 1498 registrants identified in the AuSCR as dying in hospital, 1440 (96%) were also recorded by the NDI as dying in hospital. In-hospital death in AuSCR data had 98.7% sensitivity and 99.6% specificity for predicting in-hospital death in the NDI. CONCLUSION: We report the first linkage of data from an Australian national clinical quality disease registry with routinely collected data from several national and state government health datasets. Data linkage enriches the clinical registry dataset and provides additional information beyond that for the acute care setting and quality of life at follow-up, allowing clinical outcomes for people with stroke (mortality and hospital contacts) to be more comprehensively assessed.