NSW Combined Admitted Patient Epidemiology Data and ABS population estimates (SAPHaRI). Centre for Epidemiology and Evidence, NSW Ministry of Health.
Only NSW residents are included. Rehabilitation episodes are excluded. Figures are based on where a person resides, rather than where they are treated. Hospital separations were classified using ICD-10-AM. Rates were age-adjusted using the Australian population as at 30 June 2001.
A recent policy change (PD2017_015) resulted in patients treated solely within the emergency department being excluded from this indicator report. Please note that a minority of patients being managed in short stay areas of emergency departments are still included. Further information is found in a paper in the HealthStatsPLUS Methods tab on this website.
Numbers for recent years include an estimate of the small number of hospitalisations of NSW residents in interstate public hospitals, data for which were unavailable at the time of production. Further details can be found in the Methods tab in the following HealthStats NSW indicator: http://www.healthstats.nsw.gov.au/Indicator/bod_hos_cat
All NSW public hospitals, public psychiatric hospitals, public multi-purpose services, private hospitals and private day procedure centres in NSW report data on patients admitted for care to the NSW Ministry of Health. Patient separations from developmental disability institutions and private nursing homes are not included. These reported data, from about 400 different facilities in NSW, are called the NSW Admitted Patient Data Collection (APDC).
The collection also includes data relating to NSW residents hospitalised interstate (see below in Imputation for more details) and in Commonwealth Department of Veterans’ Affairs facilities.
Each reporting facility has its own Patient Administration System (PAS), there are five types of these in NSW: HNMA Millenium (administered by Cerner), WinPAS, iPM (I-Soft), HOSPAS (legacy system being phased out and replaced with other systems) and ISCOS, which is the Inpatient Statistics Collection On-line System used by private hospitals. Data from the PAS systems are loaded into the Health Information Exchange (HIE) in a standard format. The HIE is the data warehouse for the whole NSW health system maintained by the NSW Ministry of Health which is accessed by authorised staff across the health system and in the NSW Ministry of Health. Data from the HIE are extracted and loaded onto the Secure Analytics for Population Health Research and Intelligence (SAPHaRI) warehouse, administered by the Centre for Epidemiology and Evidence and used for this report.
The Admitted Patient Data Collection (APDC) is a census of all inpatients treated in NSW and includes data on NSW residents treated in other states. The APDC was, up to 2002, known as the Inpatient Statistics Collection. The APDC contains approximately 70 variables and is based on a financial year cycle beginning on 1 July and ending on 30 June of the following year.
The APDC data used in this report are from the SAPHaRI (Secure Analytics for Population Health Research and Intelligence) data warehouse, maintained by the Centre for Epidemiology and Evidence. The APDC data is extracted from the Health Information Exchange (HIE) and undergoes a quality assurance and standardisation process before being loaded onto SAPHaRI in a SAS dataset format.
Further information on the APDC and SAPHaRI is available in this report in Methods tab under The Admitted Patient Data Collection title.
3.1 Principal diagnosis and additional diagnoses coded to the ICD-9-CM and ICD-10-AM
Each hospital episode in the APDC is described by a principal diagnosis and additional diagnoses, which are coded using the International Statistical Classification of Diseases and Related Health Problems: ICD-9-CM (up to June 1998) and ICD-10-AM (from July 1998 onwards).
In this report the count of hospitalisations for a condition is based mainly on principal diagnosis. If an indicator contains analysis of data in additional diagnosis fields as well ('comorbidities'), this is clearly stated in the title of an indicator and in the Notes. The Notes specify how many additional diagnosis fields were included in the analysis. Another exception is the topic of injury and poisoning where the count is based on ‘external cause of injury’. See Methods for injury and poisoning indicators.
The number of additional diagnoses that are included in the hospital records is restricted to conditions which fulfil several requirements, including direct relevance to the treatment and management of the principal diagnosis. This ensures that only the most resource intensive or clinically relevant conditions are listed for that hospitalisation rather than all comorbidities that a patient may have. Data on additional hospital diagnoses cannot therefore be used to estimate the prevalence of a condition in the community.
3.2 Procedures coded to Australian Classification of Health Interventions
Procedures performed in Australian hospitals are coded in medical records using the Australian Classification of Health Interventions (ACHI) published by the National Centre for Classification in Health. This classification is based on the Commonwealth Medicare Benefits Schedule and relates to anatomy rather than surgical specialty.
Up to 30 June 1998, the ICD-9-CM Procedure Classification was used in Australia. This was based on WHO Surgical procedures (edition 5) and was not revised and carried beyond 1998 by the WHO due to the rapid advancements in the field of procedures (National Coding Centre 1996).
On 1 July 1998, both the ACHI and the ICD-10-AM were introduced in NSW. They are revised every two years. The ICD-10 is the WHO classification but the AM suffix stands for Australian Modification, which adds detail necessary to describe practice in Australian hospitals. The ICD-10-AM is fully compatible with ICD-10 (NCCH 2006).
Up to the fourth edition of ICD-10-AM in 2004, the ACHI was published as a part of the ICD manuals (volume 3 and 4), from the fifth edition in 2006 the titles of the ACHI publication emphasise that this is a classification independent from the ICD.
Both ICD-9-CM Procedure Classification (up to and including 1997-98) and Australian Classification of Health Interventions (from 1998-99 onwards) are used in this report.
3.3 Episode of care based count of hospitalisations
The count of hospitalisations in this report is based on an episode of care from 1 July 1998 (ISC EOC datasets on SAPHaRI). A patient can have several episodes of care during one hospital stay, that is, between the formal admission and the formal discharge (separation) from hospital.
The episode of care is defined by a service category. An episode of care starts when the hospital stay starts or when the service category changes. There are ten service categories: acute care, rehabilitation care, palliative care, maintenance care, newborn care, other care, geriatric evaluation and management, psychogeriatric care, organ procurement-posthumous and hospital boarder.
A new episode of care starts also when a patient is on leave from hospital: more than 4 days away from any hospital and more than 10 days away from psychiatric hospitals.
3.4 Overnight and day-only hospital stays are included
Both overnight and day-only hospitalisations are included in this report, unlike in the national reporting on hospital statistics (AIHW Health services series no. 40. Cat. no. HSE 107 2011), where day-only hospitalisations are not included.
The only exceptions are the count and rate of hospitalisation for falls in elderly (persons aged 65 years and over) in NSW, where day-only hospitalisations are excluded from the key indicator reports in NSW. NSW performance reporting of hospitalisations for falls in elderly in NSW includes overnight (and longer) hospitalisations. However, in this report, an analysis of day-only hospitalisations and the total of overnight and day-only hospitalisations are also included in the relevant indicator for comparison and completeness.
3.5 Full census of hospitalisations from 1993-94 and sampling factor prior to 1993-94
In 1993-94 the APDC (then known as the Inpatient Statistics Collection) was a fully enumerated survey (that is a census) for the first time. Datasets containing financial years earlier than 1993-94 are based on estimates from a sample of all inpatient data in some hospitals, partiularly in rural areas, and their use in analysis requires the inclusion of a sampling factor weighting variable.
3.6 Separation date determines the year of hospitalisation
The main record file of the hospital stay for a patient is created or completed on separation from hospital when all relevant documentation is made available to hospital medical record departments. Consequently, the main reason for hospitalisation (principal diagnosis) completed at separation, may be different from the admitting diagnosis. The hospitalisation is counted in the year when the separation took place even if the hospitalisation period occurred predominantly in the previous financial year. For example a patient discharged on 1 July after a 4 week hospital stay would be counted as hospitalised in the new financial year.
3.7 Imputation of interstate hospitalisations in the last year of data
At the time when the NSW Ministry of Health completes the Admitted Patient Data Collection for the previous financial year, data on hospitalisations of NSW residents in other states are usually not available and so interstate hospitalisations for the latest year is always ‘imputed’ from the previous three years in this report. This imputation process estimates the number of hospitalisations occurring in other states for each diagnosis in previous years and adds these numbers to the latest year of data. When the actual data become available, the number and rates for the affected year are re-calculated.
3.8 Summary of major changes in the hospital data on SAPHaRI
1988-89: Hospital data included from the Inpatients Statistics Collection (ISC) counted on the basis of a "period of stay" in hospital (ie multiple episodes of care). ICD-9-CM used and sampling from some hospitals (requiring a sampling factor for weighting numbers in these hospitals).
1993-94: Admitted Patient Data Collection (APDC) is a fully enumerated census of hospitalisations.
1998-99 onwards: APDC starts to be counted as episodes of care. ICD-10-AM replaces ICD-9-CM; and Australian Classification of Health Interventions replaces ICD-9-CM Procedure Classification.
Imputation for interstate hospitalisations: The latest year of data (number and rates) are ‘imputed’ for missing interstate hospitalisations for NSW residents. The actual number of interstate hospitalisations is included when available.
4.1 Differences in publication schedules
The APDC dataset is continuously updated because it is not uncommon to receive additional records or additional information on records already supplied well after the close of a financial year. Consequently data on hospitalisations in NSW from different sources, such as this report and the AIHW report, will always differ slightly due to different publication schedules.
4.2 Imputation of interstate hospitalisations in the latest year of data
In this report imputation methods are used to estimate the number of hospitalisations of NSW residents occurring elsewhere in Australia in the latest year due to a lag in receiving this information (see above). Over some periods of time two last years of data need to be imputed. Refer to Notes in the indicator for confirmation how many years are imputed at the time. Estimates may vary slightly from the estimates in other releases of this report or other reports because of the imputation. The actual number of interstate hospitalisations is included when relevant.
4.3 Definition of hospitalisation
Both overnight and day-only hospitalisations are included in this report, unlike in the national reporting on hospital statistics, where only overnight hospitalisations are included (AIHW Health services series no. 40. Cat. no. HSE 107 2011).
4.4 Different projected populations
For the calculation of rates, the NSW Ministry of Health uses population projections based on the population projections prepared by the NSW Department of Planning. Refer to Methods in Population-Demography topic for further information on projected populations and other issues mentioned here. The rates in this report are expressed as a number per 100,000 population.
Rates published by the Australian Institute of Health and Welfare may be expressed differently (per 1,000 or 10,000 population) and use different projected population estimates for NSW. The population estimates, which are not projected, are likely to be the same, as these are based on the estimated residential populations published by the ABS.
The APDC datasets contain information on inpatient hospital activity. Emergency department data and Outpatient activity data are also available to report on hospital activity.
Australian Institute of Health and Welfare. Australian hospital statistics 2009–10. Health services series no. 40. Cat. no. HSE 107. Canberra: AIHW, 2011. Available at http://www.aihw.gov.au/publication-detail/?id=10737418863 (Cited on April 2011).
National Centre for Classification in Health. The International statistical classification of diseases and related health problems, 10th Revision, Australian Modification (ICD-10-AM). Australian Coding Standards. Sydney: NCCH, 2006.
National Coding Centre. The Australian version of the International Classification of Diseases, 9th revision, clinical modification (ICD-9-CM). Sydney: University of Sydney, 1996.
|Description||ICD-10 & ICD-10-AM||Comments|
|Coronary heart disease||I20-I25||All records are included except those involving rehabilitation, NSW residents only, all ages.
This indicator uses principal diagnosis only.
• Circulatory diseases cause more than 15,000 deaths and 150,000 hospitalisations of NSW residents in each year. Coronary heart disease and atrial fibrillation and flutter contribute the most to these diseases' hospitalisation burden, followed by heart failure and strokes.
• Death rates, and numbers of deaths, from circulatory disease are consistently higher in males than in females. Death rates are higher in Inner regional, Outer regional and Remote areas of NSW than in Major cities.
• Death rates from all forms of circulatory disease have more than halved in the last twenty years after adjusting for population ageing. This is due to both:
• decreased incidence, associated with reductions in some risk factors, including smoking, saturated fats in the diet, and levels of blood pressure;
• increased survival, as a result of improvements in medical and surgical treatment and follow-up care.
• Coronary heart disease caused 5,928 deaths in 2017. Coronary heart disease was the principal reason for 46,602 hospitalisations in NSW in 2017-18.
• Stroke caused just over 2,803 deaths in NSW in 2017. Stroke was the principal reason for 13,093 hospitalisations in NSW in 2017-18.
• Heart failure was the underlying cause of 1,116 deaths in NSW in 2017 and was a contributing cause in many more. Heart failure was the principal reason for 17,543 hospitalisations in NSW in 2017-18.
• In the treatment of coronary heart disease, the number of percutaneous transluminal angioplasty (PCTA) procedures (with and without stents) first exceeded the number of the more invasive coronary artery bypass graft (CABG) procedures in 2000-01. More than 15,000 PCTAs were performed in 2017-18, more than three times as many as CABGs at around 4,000 procedures.
Cardiovascular (or circulatory) diseases comprise all diseases of the heart and blood vessels. Among these diseases, the four types responsible for the most deaths in NSW are: coronary heart disease (or ischaemic heart disease), stroke (or cerebrovascular disease), heart failure, and peripheral vascular disease. Other causes of death are cardiac arrhythmias (most notably atrial fibrillation), heart valve disorders, non-ischaemic cardiomyopathies, pulmonary embolism, and hypertensive renal and heart disease. Significant causes of morbidity include hypertension, deep vein thrombosis, haemorrhoids and varicose veins.
Cardiovascular diseases accounted for 14% of the total disease burden in Australia in 2015, second only to cancers. The burden from cardiovascular diseases was predominantly fatal (78.5%) with only 21.5% due to non-fatal burden. Coronary (ischaemic) heart disease ranked highest in total individual disease burden (6.9% of the total burden) and stroke ranked ninth highest (2.7% of the total disease burden).
Presently, cardiovascular diseases account for around 48,000 deaths in Australia (around 33-34% of all deaths), more than any other group of diseases. This proportion has been in decline since 1970, when nationally cardiovascular diseases were responsible for over half of all deaths.
The four major causes of death from cardiovascular disease share a number of behavioural risk factors (tobacco smoking, physical inactivity, poor diet, risky alcohol consumption) leading to physiological risk factors (high blood pressure, elevated blood lipids, diabetes mellitus, and overweight or obesity).
Australian Institute of Health and Welfare 2019. Australian Burden of Disease Study: Impact and causes of illness and death in Australia 2015. Australian Burden of Disease Study series no. 19. BOD 22. Canberra: AIHW at: https://www.aihw.gov.au/reports/burden-of-disease/burden-disease-study-illness-death-2015-summary/contents/table-of-contents
Circulatory diseases share many modifiable risk factors with other lifestyle-related chronic diseases such as type 2 diabetes. These include smoking, physical inactivity, poor diet, harmful alcohol consumption and being overweight. This means that strategies related to the prevention, early detection and optimal management of these risk factors will lead to better health outcomes for people with circulatory diseases and other lifestyle-related chronic diseases.
Information on NSW Health programs and policies is available at http://www.health.nsw.gov.au/healthyliving/Pages/default.aspx.