What is multimorbidity and comorbidity?
Many people with chronic health conditions do not have a single, predominant condition. Rather, they experience multimorbidity – the presence of 2 or more chronic conditions in a person at the same time (AIHW 2021).
The health effect of multimorbidity can be greater than the combined effect of individual conditions. People with multimorbidity often have more severe illness and use more health services, including increased contact with primary health care services, with more complex hospitalisations and poorer outcomes.
The additional health conditions experienced by a person who has chronic kidney disease (CKD) is known as comorbidity. Diabetes and cardiovascular disease are common comorbidities among people with CKD (AIHW 2007, 2014). On this web page, much of the focus is on the comorbidity of CKD in combination with diabetes and/or cardiovascular disease.
An ageing population, along with unfavourable trends in some risk factors and a high prevalence of chronic disease in the community is expected to result in a rise in the number of people with CKD comorbidity, and higher rates of CKD among people with other chronic conditions.
Based on the Australian Bureau of Statistics (ABS) 2017–18 National Health Survey (NHS), an estimated 238,000 Australians had CKD as a long-term condition. Almost all (234,000 or 98%) had at least 1 of 9 other selected chronic conditions, including arthritis, mental and behavioural conditions, cardiovascular disease, back problems, diabetes, osteoporosis, chronic obstructive pulmonary disease and cancer (ABS 2018a).
CKD was present in:
- 6.6% of people with heart, stroke and vascular disease
- 5.8% of people with diabetes
- 4.4% of people with cancer
- 4.3% of people with chronic obstructive pulmonary disease (ABS 2018a).
Note that these data are based on self-report and rely on survey respondents providing accurate information – some conditions, such as CKD, are substantially under-reported in the NHS. Of the estimated 1.7 million adults who had biomedical signs of CKD in 2011–12, only 6.1% reported having kidney disease (ABS 2013a).
Prevalence of chronic kidney disease, diabetes, and heart, stroke and vascular disease
Based on the ABS 2011–12 National Health Measures Survey, an estimated 2.8 million Australian adults aged 18 and over (18%) had biomedical signs of CKD, diabetes, or heart, stroke and vascular disease (ABS 2013b). Of these, 2.2 million (14% of adults) had only 1 of CKD, diabetes, or heart, stroke and vascular disease. Another 621,000 (4.0% of adults) had at least 2 of CKD, diabetes, or heart, stroke and vascular disease:
- 241,000 adults (1.5%) had CKD as well as heart, stroke and vascular disease
- 201,000 adults (1.3%) had CKD and diabetes
- 103,000 adults (0.7%) had heart, stroke and vascular disease as well as diabetes
- 77,000 adults (0.5%) had all 3 conditions (Figure 1).
Among adults with biomedical signs of CKD in 2011–12, 44% also had diabetes and/or heart, stroke and vascular disease.
The prevalence of comorbidity of CKD with diabetes and/or heart, stroke and vascular disease rose with age, from 2.1% of adults aged 55–64 to 14% of adults aged 65 and over.
Figure 1: Prevalence of chronic kidney disease, diabetes, and heart, stroke and vascular disease (HSVD) and their comorbidity, people aged 18 and over, 2011–12