Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12611000512921
Ethics application status
Approved
Date submitted
20/04/2011
Date registered
17/05/2011
Date last updated
17/05/2011
Type of registration
Retrospectively registered

Titles & IDs
Public title
The OASIS study: Observational Australian Study Investigating the epidemiology, outcomes and management of non-traumatic Subarachnoid haemorrhage.
Scientific title
Observational Australian Study Investigating the epidemiology, outcomes and management of non-traumatic Subarachnoid haemorrhage using linked health administrative data.
Secondary ID [1] 260014 0
Nil
Universal Trial Number (UTN)
Trial acronym
OASIS
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Subarachnoid Haemorrhage (non-traumatic) 265676 0
Condition category
Condition code
Stroke 265811 265811 0 0
Haemorrhagic
Public Health 265902 265902 0 0
Epidemiology
Public Health 265903 265903 0 0
Health service research

Intervention/exposure
Study type
Observational
Patient registry
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Non-traumatic subarachnoid haemorrhage (SAH) accounts for 1 to 7% of all strokes and around 30% with SAH die within one month. SAH is characterised by bleeding in the subarachnoid space between the thin arachnoid and pia mater coverings of the brain. Ruptured cerebral aneurysms account for 85% of non-traumatic SAH.

Using linked administrative data-sets, it is now feasible to examine SAH care. We aim to use routinely collected data to carry out a large-scale analysis of outcomes for SAH. We aim to determine short and longer-term quality of care and the safety and efficacy of procedures undertaken to treat SAH in a contemporary acute care setting. Our proposed project is a cost effective, timely alternative to existing labour-intensive efforts to observe SAH care and outcomes. Our methods minimise selection and referral biases, utilising state-wide data from the largest cohort of SAH patients ever studied in Australia (~5,000). Our proposed project aims to analyse linked administrative data-bases to identify patients with SAH and characterise short and long-term outcomes, such as fact and cause of death and re-admission to hospital.

Outcomes will be assessed from time of hospital admission to up to 10 years post-hospitalisation.
Intervention code [1] 264433 0
Not applicable
Comparator / control treatment
Not applicable
Control group
Uncontrolled

Outcomes
Primary outcome [1] 266562 0
Epidemiological description of outcomes for non-traumatic SAH will be undertaken. Specifically, the following analyses will be conducted
-Age- and sex-standardised incidence;
-Mortality rates;
-Relative survival amongst 90-day survivors;
-Recurrent SAH
-Uptake of rehabilitation and "exposure" to hospital rehabilitation.

Variation in these outcomes according to patient, hospital and disease characteristics, and year of hospital admission will be explored.

These outcomes will be determined by linkage of hospitalisation data to subsequent hospitalisations and mortality indices (cause and fact of death).
Timepoint [1] 266562 0
-Yearly incidence rates will be calculated for the years 2000-2007.
-Data to estimate mortality at 24-hours, 48-hours, 7-days, 30-days, 90-days, 180-days, 1-year, and up to ten years will be available (ie from 2000 to 2010).
-1-year to up to 10-years relative survival will be calculated.
-Risk of recurrent non-traumatic SAH at up to nine years after hospital admission for acute SAH (ie from 2000 to 2009).
Primary outcome [2] 266563 0
A proxy measure of disability, "time spent in hospital", will be determined from hospital admissions data, adapting a validated measure in which time spent at home was correlated with standardised measures of disability in stroke patients (Quinn, Dawson, Lees et al 2008). The number of days spent in hospital will be calculated and this measure will be applied to those patients who survive the follow-up period.

Variation in these outcomes according to patient, hospital and disease characteristics, and year of hospital admission will be explored.

References: Quinn TJ, Dawson J, Lees JS, Chang TP, Walters MR, Lees KR. Time Spent at Home Poststroke
"Home-Time" a Meaningful and Robust Outcome Measure for Stroke Trials. Stroke 2008; 39: 231.
Timepoint [2] 266563 0
90-days, 12-months and up to 9-years following hospitalisation for non-traumatic SAH.
Primary outcome [3] 266611 0
Management and patterns of care of non-traumatic SAH. Examples of outcomes investigated are as follows:
-Uptake of neurosurgical interventions (eg clipping, coiling, CSF shunting, intraventricular drainage);
-Arrival and transfer to a hospital offering a neurosurgical unit (ie Category A stroke unit hospital);
-ED triage prior to admission to hospital for SAH or prior to death from SAH;
-Time from hospital admission to administration of neurosurgical interventions;
-Hospital caseload;
-ICU and mechanical ventilation;
-modifiable patient complications of care;
-Uptake of diagnostic procedures



Variation in these outcomes according to patient, hospital and disease characteristics, and year of hospital admission will be explored.
Timepoint [3] 266611 0
These outcomes are "in-hospital" outcomes from July 1, 2000 to June 30, 2009.
Secondary outcome [1] 276092 0
Methodological sub-studies are planned, including:
-Validation of administrative recording of SAH and other comorbidities, procedures and patient characteristics;
-Development of a "severity index" against gold standard specialist assessment using Glasgow Coma Score, Hunt and Hess Scale and World Federation of Neurological Sciences scales;
-effect of "look-back" period for comorbidity, herald symptoms and other antecedents;
-Fact of death as a proxy for "SAH cause-specific death" at 30-days, 90-days and 12-months.
Timepoint [1] 276092 0
These outcomes will utilise hospitalisation data from July 1, 2000 to June 30, 2009 and death data from July 1, 2000 to June 30 2010.

Eligibility
Key inclusion criteria
NSW residents aged 18 years or over with a hospital separation for SAH or who died outside hospital with SAH noted as a cause of death.
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Patients with the following criteria will be excluded:
-a concomitant code for head trauma or traumatic injury;
-residents of other Australian states;
-patients with diagnostic codes (as selected by clinical experts) for brain malignancy or benign brain tumour.

Study design
Purpose
Natural history
Duration
Longitudinal
Selection
Defined population
Timing
Both
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
1/07/2000
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
4000
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 264943 0
Government body
Name [1] 264943 0
National Health and Medical Research Council of Australia
Country [1] 264943 0
Australia
Primary sponsor type
Government body
Name
National Health and Medical Research Council of Australia
Address
Level 1
16 Marcus Clarke Street
Canberra ACT 2601
Country
Australia
Secondary sponsor category [1] 264040 0
None
Name [1] 264040 0
Address [1] 264040 0
Country [1] 264040 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 266900 0
NSW Population & Health Services Research Ethics Committee
Ethics committee address [1] 266900 0
Cancer Institute NSW, Australian Technology Park, Level 9, 8 Central Avenue, Eveleigh, NSW 2015
Ethics committee country [1] 266900 0
Australia
Date submitted for ethics approval [1] 266900 0
Approval date [1] 266900 0
15/03/2007
Ethics approval number [1] 266900 0
2007/03/023

Summary
Brief summary
Subarachnoid haemorrhage (SAH) accounts for 5% of all strokes, yet 30% of people affected with SAH will die within 90 days and survivors are often disabled. Unlike ischaemic stroke, there is a relatively higher risk of SAH in younger age groups, yet risk factors are ill-defined. Therefore, determining health service variables impacting on outcomes will inform policy and practice. It is now feasible to examine SAH care and its outcomes on a large scale at a relatively modest cost. We will analyse linked routinely collected morbidity and mortality data to explore outcomes and patterns of care in SAH on a large scale. The study will describe discharge destinations and readmissions and be able to quantify the effect of hospital services according to different models of care, resources and settings (eg principal and non-principal referral, neurosurgical vs non-neurosurgical) and neurovascular interventions. Such a large-scale analysis of services and care patterns will be of international significance informing bed-side care and health service planning to improve individual, health service and societal outcomes. We hypothesise that the risk of 30-day, 90-day and 12 month all-cause mortality will be correlated with health service delivery for patients with SAH. Specifically, patients with SAH admitted to a hospital offering a neurosurgical unit will have a reduced risk of all-cause and disease-specific mortality and spend less time in hospital in the year after a SAH. There will be significant variation in all-cause and disease-specific mortality and hospital re-admission according to: hospital type (eg principal referral versus other, rural versus urban location), caseload, and patient and disease characteristics. We will identify emergency presentations and hospital separations for SAH in New South Wales from July 2000 until June 2010. Data from these sources will be linked to the NSW Registry of Birth, Deaths and Marriages (fact of death) and ABS Causes of Death data.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 32502 0
Address 32502 0
Country 32502 0
Phone 32502 0
Fax 32502 0
Email 32502 0
Contact person for public queries
Name 15749 0
A/Professor John M Worthington
Address 15749 0
Department of Neurophysiology
Liverpool Hospital,
Elizabeth Street
Level 1,
Clinical Services Building
Liverpool Health Service
Liverpool NSW 2170
Country 15749 0
Australia
Phone 15749 0
61 2 9828 3643
Fax 15749 0
Email 15749 0
[email protected]
Contact person for scientific queries
Name 6677 0
A/Professor John M Worthington
Address 6677 0
Department of Neurophysiology
Liverpool Hospital,
Elizabeth Street
Level 1,
Clinical Services Building
Liverpool Health Service
Liverpool NSW 2170
Country 6677 0
Australia
Phone 6677 0
61 2 9828 3643
Fax 6677 0
Email 6677 0
[email protected]

No information has been provided regarding IPD availability


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

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