Figure 12 illustrates the ten most common disease groups reported as the patient's principal diagnosis using ICD-10-AM (Box 2) for which patients aged 85 and over received care in hospital.
For patients aged 85 and over, the most common ICD-10-AM principal diagnosis chapter was Factors influencing health status and contact with health services (26.3%, 181,677 separations), which was also the most common ICD-10-AM principal diagnosis chapter for all separations (27.7%). This chapter includes care involving dialysis, the use of rehabilitation procedures, radiotherapy, chemotherapy and palliative care.
About 10.8% (74,814 separations) of patients aged 85 and over had a principal diagnosis in the ICD-10-AM chapter Diseases of the circulatory system, compared with 4.8% for all separations. There were also higher proportions of separations for patients aged 85 and over for Injury, poisoning and certain other consequences of external causes (68,155 or 9.9% compared with 6.4% for all separations) and Diseases of the eye and adnexa (48,269 or 7.0% compared with 3.8% for all separations).
Box 2: What are the principal diagnosis and ICD-10-AM?
The principal diagnosis is the diagnosis established after study to be chiefly responsible for occasioning the patient's episode of admitted patient care.
In 2014–15, principal diagnoses were reported using the Eighth edition of the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification (ICD-10-AM). ICD-10-AM groups together similar conditions, organised in a hierarchy of chapters, subchapters and specific categories.
Figure 12: Proportion of separations by ICD-10-AM principal diagnosis chapter for patients aged 85 and over and all separations, 2014–15, per cent
In 2014–15, the top 20 principal diagnoses (at a more detailed level, see Box 2) for separations for patients aged 85 and over represented 51% (349,644) of all separations for this age group. Care involving dialysis was the most common principal diagnosis, with 76,678 separations (11.1%); Care involving use of rehabilitation procedures 63,890 separations (9.3%) was the second most common principal diagnosis. Figure 13 presents the proportion of separations for the 20 most common principal diagnoses for those aged 85 and over compared with all hospital separations.
Figure 13: The 20 most common 3-character principal diagnoses for patients aged 85 years and over and all separations, 2014–15, per cent