Cost-effectiveness of stroke care in Aboriginal and non-Aboriginal patients: an observational cohort study in the Northern Territory of Australia

Scope and quality of economic evaluations of Aboriginal and Torres Strait Islander health programs: a systematic review

OBJECTIVES

Identify the number, type, scope and quality of economic evaluations of Aboriginal and Torres Strait Islander health programs.

METHODS

A systematic review of peer-reviewed and grey literature was conducted for articles published from 2010 to 2020 that reported a full economic evaluation of Aboriginal and Torres Strait Islander health programs. Data extraction included: type of economic evaluation, comparators, data sources and concerns, and outcome measures. Methodological quality was assessed using the Drummond checklist.

RESULTS

Thirteen publications met inclusion criteria: two cost-consequence analyses, two cost-effectiveness analyses, five cost-utility analyses, and four cost-benefit/return on investment analyses. Most studies (n=10) adopted a health system perspective and used a range of key data sources for economic analyses. Ten studies identified data access limitations that restricted analyses and two studies identified data quality concerns. Twelve studies were of good methodological quality and one was of average quality.

CONCLUSIONS

Despite significant investment in strategies to close the gap in health outcomes for Aboriginal and Torres Strait Islander people, there is limited evidence about what constitutes a cost-effective investment in Aboriginal and Torres Strait Islander healthcare.

IMPLICATIONS FOR PUBLIC HEALTH

More economic evaluation is required to justify the significant investment in health programs for Aboriginal and Torres Strait Islander people.

Patients characteristics and health outcomes in patients hospitalized with hypomagnesemia: a retrospective study from a single center in the Northern Territory of Australia

AIM

This research aimed to study the clinical and biochemical characteristics and health outcomes of patients admitted and found to have hypomagnesemia in an Australian hospital with a high proportion of Indigenous Australians.

METHODS

A retrospective cohort study was conducted of all patients with hypomagnesemia hospitalised between 1st August 2008 and 31st December 2014 at Royal Darwin Hospital (RDH). All relevant demographic, clinical, and biochemical were collected from patients' medical records. The hospital database was reviewed in January 2018 for mortality of all included patients.

RESULTS

876 patients had been admitted with a confirmed diagnosis of hypomagnesemia during the study period, with mean follow up period of 4.0 ±2.7 years. The mean age at admission was 52.4 ± 19.1 years, 52.2% were females and, 56.5% were Indigenous Australians. Chronic kidney disease (99.7%), excessive alcohol consumption (45.7%), hypertension (43.9%), and respiratory diseases (15.0%) were the most common conditions in these patients. Hypomagnesemia was associated with prolonged length of hospital stay. Most patients did not receive treatment for hypomagnesaemia during admission. During the follow-up period, 38.6% of patients died, and the most common causes of death were malignancies (29.9%).

CONCLUSION

Hypomagnesemia was a common and under-treated condition in hospitalised patients and was associated with poor health outcomes. Therefore, hospitals should develop guidelines for replacing and monitoring magnesium levels during hospitalisation, achieving better outcomes. This article is protected by copyright. All rights reserved.

Stroke Epidemiology in Oceania: A Review

BACKGROUND AND PURPOSE

Oceania, comprising the regions Australasia, Melanesia, Micronesia, and Polynesia, is home to 42 million living in 8.5 million square kilometres of land. This paper comprises a review of the epidemiology of stroke in countries in this region.

METHODS

Information on epidemiology of stroke in Oceania was sought from data from the Global Burden of Disease (GBD) study (incidence, mortality, incidence:mortality ratio [IMR], prevalence, disability-adjusted life-years [DALYs] lost due to stroke, and subtypes), World Health Organization (WHO) (vascular risk factors in the community), and PubMed (incidence, prevalence, and stroke subtypes). Data were analyzed by region to allow inter-country comparison within each region.

RESULTS

In 2010, age- and sex-standardized stroke mortality rates were lowest in Australasia (29.85-31.67/100,000) and highest in Melanesia and Micronesia (56.04-187.56/100,000), with wide ranges especially in Melanesia. Incidence rates were lowest in Australasia (101.36-105.54/100,000), similarly high elsewhere. Standardized IMR (0.98-3.39) was the inverse of the mortality rates and mirrored the prevalence rates (202.91-522.29/100,000). DALY rates (398.22-3,781.78/100,0000) mirrored the mortality rates. Stroke risk factors show a variable pattern - hypertension is generally the most common medical risk factor among males (18.0-26.6%), while among females, diabetes mellitus is the most common in Micronesia and Polynesia (21.5-28.4%). Among the lifestyle factors, current smoking is the most common in Melanesia among males, while obesity is generally the most common factor among females. Ischaemic stroke comprises 70% of stroke subtypes. Trend data show significant falls in standardized mortality rates and DALYs in most regions and falls in incidence in almost all countries. There is significant economic impact, particularly due to young strokes; some ethnicities are at higher risk than others, for example, Maoris and Pacific Islanders.

CONCLUSIONS

Stroke is a major healthcare problem in Oceania. Variations in stroke epidemiology are found between countries in Oceania. Data are lacking in some; more research into the burden of stroke in Oceania is needed. With the expected increase in life expectancy and vascular risk factors, the burden of stroke in Oceania will likely rise. Some of the disparities in stroke burden may be addressed by great investment in healthcare.

Top End Pulmonary Hypertension Study: Understanding Epidemiology, Therapeutic Gaps and Prognosis in Remote Australian Setting

INTRODUCTION

The Top End of Australia has a high proportion of Indigenous people with a high burden of chronic cardiac and pulmonary diseases likely to contribute to pulmonary hypertension (PH). The epidemiology of PH has not been previously studied in this region.

METHODS

Patients with PH were identified from the Northern Territory echocardiography database from January 2010 to December 2015 and followed to the end of 2019 or death. Pulmonary hypertension was defined as a tricuspid regurgitation velocity ≥2.75 m/s measured by Doppler echocardiography. The aetiology of PH, as categorised by published guidelines, was determined by reviewing electronic health records.

RESULTS

1,764 patients were identified comprising 49% males and 45% Indigenous people. The prevalence of PH was 955 per 100,000 population (with corresponding prevalence of 1,587 for Indigenous people). Hypertension, atrial fibrillation, diabetes and respiratory disease were present in 85%, 45%, 41% and 39%, respectively. Left heart disease was the leading cause for PH (58%), the majority suffering from valvular disease (predominantly rheumatic). Pulmonary arterial hypertension (PAH), respiratory disease related PH, chronic thromboembolic PH (CTEPH) and unclear multifactorial PH represented 4%, 16%, 2% and 3%, respectively. Underlying causes were not identifiable in 17% of the patients. Only 31% of potentially eligible patients were on PAH-specific therapy. At census, there was 40% mortality, with major predictors being age, estimated pulmonary artery systolic pressure (ePASP) and Indigenous ethnicity.

CONCLUSION

Pulmonary hypertension is prevalent in Northern Australia, with a high frequency of modifiable risk factors and other treatable conditions. Whether earlier diagnosis, interpretation and intervention improve outcomes merits further assessment.

All-cause mortality following low-dose aspirin treatment for patients with high cardiovascular risk in remote Australian Aboriginal communities: an observational study

OBJECTIVES

To evaluate the benefit and risk of low-dose acetylsalicylic acid (aspirin) in patients from remote Aboriginal communities in the Northern Territory, Australia.

DESIGN

Retrospective cohort study using primary care and hospital data routinely used for healthcare. Aspirin users and non-users were compared before and after controlling confounders by matching. Marginal structural models (MSM) were applied to ascertain the benefit and risk.

SETTING

The benefit and harm of aspirin were investigated in patients aged ≥18 years from 54 remote Aboriginal communities.

PARTICIPANTS

None had a previous cardiovascular event or major bleeds. Patients on anticoagulants or other antiplatelets were excluded.

INTERVENTION

Aspirin at a dose of 75-162 mg/day.

OUTCOME MEASURES

Endpoints were all-cause, cardiovascular mortality and incidences of cardiovascular events and major bleeds.

RESULTS

8167 predominantly Aboriginal adults were included and followed between July 2009 and June 2017 (aspirin users n=1865, non-users n=6302, mean follow-up 4 years with hospitalisations 6.4 per person). Univariate analysis found material differences in demographics, prevalence of chronic diseases and outcome measures between aspirin users and non-users before matching. After matching, aspirin was significantly associated with reduced all-cause mortality (HR=0.45: 95% CI 0.34 to 0.60; p<0.001), but not bleeding (HR=1.13: 95% CI 0.39 to 3.26; p=0.820). After using MSMs to eliminate the effects of confounders, loss of follow-up and time dependency of treatment, aspirin was associated with reduced all-cause mortality (HR=0.60: 95% CI 0.47 to 0.76; p<0.001), independent of age (HR=1.06; p<0.001), presence of diabetes (HR=1.42; p<0.001), hypertension (HR=1.61; p<0.001) and alcohol abuse (HR=1.81; p<0.001). No association between aspirin and major bleeding was found (HR=1.14: 95% CI 0.48 to 2.73; p=0.765). Sensitivity analysis suggested these findings were unlikely to have been the result of unmeasured confounding.

CONCLUSION

Aspirin was associated with reduced all-cause mortality. Bleeding risk was less compared with survival benefits. Aspirin should be considered for primary prevention in Aboriginal people with high cardiovascular risk.

Amputations in patients with diabetic foot ulcer: a retrospective study from a single centre in the Northern Territory of Australia

BACKGROUND

Lower extremity amputations (LEAs) in diabetic patients are common in the indigenous population. There is no published data from the Northern Territory.

METHODS

All patients with diabetic foot ulcer, presenting for the first time to the multi-disciplinary foot clinic at Royal Darwin Hospital, between January 2003 and June 2015, were included. These patients were followed until 2017, or death. LEA rates over the follow-up period and the risk factors were studied.

RESULTS

Of the 513 included patients, 62.8% were males and 48.2% were indigenous. The majority (93.6%) had type 2 diabetes with median diabetes duration of 7.0 years (interquartile range 3-12). During the follow-up period of 5.8 years (interquartile range 3.1-9.8), a total of 435 LEAs (16.6% major; 34.7% minor) occurred in 263 patients (mean age 57.0 ± 11.8 years). In multivariate analysis, the following variables were associated with LEAs (adjusted odds ratio (95% confidence interval)): prior LEA (4.49 (1.69-11.9)); peripheral vascular disease (2.67 (1.27-5.59)); forefoot ulcer (7.72 (2.61-22.7)); Wagner grade 2 (3.71 (1.87-7.36)); and Wagner grade 3 (17.02 (3.77-76.72)). Indigenous patients were 1.8 times more likely to have LEAs than non-indigenous patients. Indigenous amputees were approximately 9 years younger than their non-indigenous counterparts.

CONCLUSION

Half of patients presenting with diabetic foot ulcer had LEA during follow-up. Prior LEAs, peripheral vascular disease, forefoot ulcers and higher Wagner grades were independent risk factors for LEA. Indigenous patients were at higher risk for LEAs and were younger at the time of amputation.

Mortality in patients with diabetic foot ulcer: a retrospective study of 513 cases from a single Centre in the Northern Territory of Australia

BACKGROUND

Diabetic foot ulcers (DFU) are a common problem in longstanding diabetes. However, mortality outcomes in Australian patients with DFU are still unclear.

METHODS

All patients with DFU presenting for the first time to the Multi-Disciplinary Foot Clinic (MDFC) at Royal Darwin Hospital, Northern Territory Australia, between January 2003 and June 2015 were included in this study. These patients were followed until 2017, or death. Individual patient data was extracted from hospital and primary care information systems. Kaplan-Meier survival curves were developed. The association between various risk factors and mortality was analysed using Cox regression.

RESULTS

In total 666 subjects were screened, and 513 were included in the final analysis. Of these subjects, 247 were Indigenous and 266 were non-Indigenous. The median follow-up period was 5.8 years (IQR, 3.1-9.8). The mean age at inclusion was 59.9 ± 12.3 years and 62.8% were males. The majority (93.6%) had type 2 diabetes and the median diabetes duration was 7 years (IQR, 3-12). There were 199 deaths, with a 5-year-mortality rate of 24.6%, and a 10-year-mortality rate of 45.4%. The mean age at death was 64.6 ± 11.8 years. In a multivariate analysis, the following variables were associated with mortality (adjusted HR, 95% CI): age 1.04 (1.02-1.05, P < 0.001); chronic kidney disease 1.22 (1.11-1.33, P < 0.001), and plasma albumin 0.96 (0.94-0.99, P < 0.05). The most common causes of death were chronic kidney disease (24.6%), cardiovascular events (19.6%), sepsis (15.6%), respiratory failure (10.0%), malignancy (9.5%) and multi-organ failure (5.0%).

CONCLUSION

Patients with DFU have high mortality. Age, chronic kidney disease, and low albumin levels increase the risk of mortality. Strategies should focus on ulcer prevention and aggressive risk factor reduction.