Estimating chronic disease prevalence among the remote ...



Estimating chronic disease prevalence among the remote Aboriginal population of the Northern Territory using multiple data sources

Yuejen Zhao, Christine Connors, Jo Wright, Steve Guthridge

Department of Health and Families, Northern Territory

Ross Bailie

Menzies School of Health Research, Northern Territory

Abstract

Objective: To determine the prevalence rates of hypertension, diabetes, ischaemic

heart disease (IHD), renal disease and chronic obstructive pulmonary disease

(COPD), and their co-occurrence among the remote Aboriginal population of the

Northern Territory (NT) in 2005.

Methods: Information from a primary care chronic disease register (CDR) and

hospital inpatient database were linked to a population list by using a unique patient

identifier. A capture-recapture method (CRM) and multivariate log-linear models

were then applied to analyse the multiple datasets to estimate the prevalence

rates for the selected diseases and case ascertainment in each data source.

Results: The NT remote Aboriginal communities had considerably higher

prevalence rates across all five chronic diseases than national health survey

figures. At ages 50 years and over, the prevalence rates for hypertension and

renal disease were above 50%, diabetes 40%, COPD 30% and IHD above 20%.

In terms of data completeness, CDR and hospital sources were both relatively

incomplete, generally around 20−60%. The most common co-occurrences for

the five chronic diseases were between hypertension, diabetes, IHD and renal

disease.

Conclusions and implications: The prevalence rates calculated using this

method are comparable to estimates from rigorous small area studies, but are

markedly higher than those from single clinical data sources. The results indicate

that there is a considerable underdiagnosis of preventable chronic diseases in the Aboriginal communities.

Keywords: Prevalence, data collection, epidemiology, chronic diseases,

Indigenous health services

For preventive and early intervention strategies for chronic disease

management to be effective, it is central to have reliable information about

the pattern of disease and exposures to major risk factors. This requirement is not

limited to one-off or intermittent estimates, but extends to systematic monitoring and

surveillance of the conditions to inform ongoing management. The implementation

of systematic monitoring is particularly important among the Northern Territory

(NT) Aboriginal population for whom noncommunicable diseases are estimated to

contribute 77% of the life expectancy gap between Aboriginal and non-Aboriginal

populations.1 The importance of chronic diseases management has prompted a

comprehensive NT intervention strategy, with a focus on five preventable chronic

diseases (PCDs) – hypertension, diabetes, ischaemic heart disease (IHD), renal

disease and chronic obstructive pulmonary disease (COPD).2 These five conditions are

also significant in the broader Australian

population and make up 22% of national

burden of disease.3 The five conditions share

several underlying characteristics. They are

commonly developed at working age after

latent exposure to a limited number of core

risk factors including poverty, childhood

malnutrition, systemic infections, tobaccosmoking, alcohol abuse, poor access to

fruit and vegetables, obesity and physical

inactivity. The conditions are characterised

as being preventable, costly to manage and

rarely curable. They also have an uncertain

time of onset, are of prolonged duration and

are complicated by acute manifestations.

In the NT, the acute manifestations of

the five conditions consume 40-56% of

public hospital resource4 and result in pain,

disability and premature death for many

Territorians. There are also substantial

indirect costs through the impact on quality

of social and family life, and work-related

productivity.

Despite national efforts to collate existing

health survey, hospital morbidity and

mortality data, there remains a paucity of

relevant epidemiological information on

prevalence, incidence and survival rates

of the chronic diseases, particularly at a

regional level.5 Existing electronic, clinical

datasets remain an under-utilised option,

with only sporadic reports on the prevalence

rates of selected preventable chronic diseases

among Indigenous Australians. The existing

estimates have been based on singlesource

data and have generally focused

on diabetes,6-8 hypertension,9,10 and renal

diseases.11,12 Recent reports have combined

these as the metabolic syndrome related

conditions.13-15 Less is known about current

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download