Potentially preventable hospitalisations
Potentially preventable hospitalisations are included as a national performance indicator in the National HealthCare Agreement. The Australian Commission on Safety and Quality in Health Care is leading a national Potentially Preventable Hospitalisations Working Party to review the evidence for inclusion of each of the PPH conditions. This Working Party includes jurisdictional and clinical representatives and the Secretariat is provided by the AIHW. In January 2015, a new definition was published.
From May 2015 onwards, potentially preventable hospitalisation reporting on HealthStats NSW uses the most recent National Health Care Agreement: P1 18-Selected potentially preventable hospitalisation definition.
Origin of the definition used in HealthStats NSW
Prior to 2015, the conditions included as the potentially preventable hospitalisations, or ambulatory care-sensitive conditions, are based on the set published by the Victorian Government Department of Human Services (VGDHS 2004) and subsequently reviewed by the Public Health Information Development Unit (Page et al. 2007).
Changes in the definition in NSW over time
Historically, the codes used to define potentially preventable hospitalisations in HealthStats differ slightly from those used in earlier editions of the Report of the Chief Health Officer, where they were referred to as ambulatory care sensitive conditions.
In 2006 in NSW the coding of diabetes was changed to include diabetes as a primary diagnosis only, which resulted in fewer cases of diabetes and therefore chronic conditions overall.
In 2007, urinary tract infections were included, which increased the number of cases in acute conditions category, and the coding of cellulitis was aligned with national standards.
In 2008, new codes covering gastroenteritis of infectious and unspecified origin were added following the expansion of the relevant ICD-10-AM codes and an accompanying change in coding practice. This resulted in an increase in the number of cases of the dehydration and gastroenteritis and consequently in the acute conditions category from 2008 and a break in continuity in that category.
Similarly, in 2010, new codes covering acute appendicitis were introduced replacing previously used codes. This resulted in a wider range of codes that had to be included in order to account for all cases of hospitalisation for perforated appendix, which is an ambulatory care sensitive condition. The number of cases included as the potentially preventable hospitalisations almost doubled in this category in the first year after the change.
After July 2010, PPH numbers and rates decreased significantly overall due to a change in the coding standards for diabetes which is a substantial contributor to total preventable hospitalisations. See the discussion of details of this and other changes in diabetes coding here.
Following each change in definition, data are recalculated for the entire span of years displayed in the report. The exception is the dehydration and gastroenteritis change in 2008 where a break in continuity occurred due to the introduction of new ICD-10-AM codes.
From 2015 onwards, HealthStats NSW uses the National Health Care Agreement: P1 18-Selected potentially preventable hospitalisation definition. The new PPH definitions apply from July 2007 nationally but, in HealthStatsNSW, the new definition applies to the whole period from 2001/02 onwards to allow for comparisons over time. The exception is the category ‘Other vaccine-preventable conditions’ which excludes‘Rotaviral enteritis-A08.0’ for years before 2006/07 as the vaccine was not on the national childhood immunisation schedule until 2007.
In 2016, HealthStats NSW applied two new exclusion rules to potentially preventable hospitalisatons. Hospital episodes with source of referral being a transfer from another hospital or a type change admission are excluded in order to reduce multiple counting of hospitalisation episodes relating to the same event. Hospital episodes with bed/unit type being hospital in the home are also excluded. These rules are applied to the whole period from 2001/02 onwards to allow for comparisons over time.
References
Australian Institute of Health and Welfare. Australian hospital statistics - Admitted patients. Available at https://www.aihw.gov.au/reports-data/myhospitals/sectors/admitted-patients
Victorian Government Department of Human Services. The Victorian Ambulatory Care Sensitive Conditions Study, 2001-02. Melbourne: VGDHS, 2004.
Page A, Ambrose S, Glover J, Hetzel D. Atlas of avoidable hospitalisations in Australia: ambulatory care-sensitive conditions. Adelaide: PHIDU, University of Adelaide and AIHW, 2007. Available at https://www.aihw.gov.au/reports/hospitals/atlas-avoidable-hospitalisations-australia/contents/table-of-contents