1. Trends in the incidence of renal failure in Australia
John Stewart, Margaret McCredie, Stephen McDonald

2. ANZDATA Registry, ANZSN 2003
Background
The patterns of incident ESRD have changed substantially over recent years
A variety of factors might contribute to this
Altered disease incidence
Altered disease outcomes
Altered referral and selection bias
Changes in the underlying popuation
ANZDATA Registry, ANZSN 2003

3. ANZDATA Registry, ANZSN 2003
Methods
Treated ESRD (ANZDATA), Australia only
Only 90+ day survivors
Indirect standardisation to Australian population values (ABS)
Changes examined in 3 groups
Age
Disease
Country of birth
ANZDATA Registry, ANZSN 2003

4. ANZDATA Registry, ANZSN 2003
Age at entry A B
New patients per year, , Australia, treated ESRD only
ANZDATA Registry, ANZSN 2003

5. ANZDATA Registry, ANZSN 2003
Age-specific changes 15 3
Non-indigenous 10
Indigenous
2.5 5 2
Rate ratio
Rate ratio 2
1.5 1 1 .5
0-14
15-24
25-34
35-44
45-54
55-64
65+
0-14
15-24
25-34
35-44
45-54
55-64
65+
Age group
Age group
Rate ratio
95% CI
Incidence rate ratios for compared to
ANZDATA Registry, ANZSN 2003

6. ANZDATA Registry, ANZSN 2003
Diseases over time
The changes in disease incidence rates from the period to was examined, stratified by age groups
Changes in most diseases are similar to the overall pattern, except
Diabetes
Hypertension / arteriopathy
Analgaesic nephropathy
ANZDATA Registry, ANZSN 2003

7. ANZDATA Registry, ANZSN 2003
Diabetic nephropathy 15 15
Type 1 diabetes
Type 2 diabetes 10 10 5 5
Rate ratio
Rate ratio 2 2
The increase in rates of type two diabetic nephropathy was considerably greater that of other primary renal disease. Furthermore, it appears to be disproportionately affecting the younger and Middle age groups. This rules out changing criteria for acceptance into treatment programs as the sole explanation. It is quite consistent, however with the increasing rates of diabetes observed in the general population over successive National heart foundation prevalence surveys and most recently the AusDiab survey 1 1 .5 .5
25-34
35-44
45-54
55-64
65+
35-44
45-54
55-64
65+
Age group
Age group
Rate ratio
95% CI
ANZDATA Registry, ANZSN 2003

8. Hypertension / analgaesic10
Analgaesic
Hypertension / vascular 2 5 1
Rate ratio
Rate ratio .5 2
This is what you would expect, among the older section of the population. The changes in the rates of analgaesic nephropathy represent the tail end of an exposure which was stopped 20 years ago. 1 .2 .5 .1
35-44
45-54
55-64
65+
45-54
55-64
65+
Age group
Age group
Rate ratio
95% CI
ANZDATA Registry, ANZSN 2003

9. ANZDATA Registry, ANZSN 2003
Place of birth
Country of birth grouped by region
Australia, British Isles, Southern Europe, Rest of Europe, Middle East, Indian sub-continent, East / South East Asia, Pacific Island
Other than Pacific Island (23% Fijian Indians) and Middle East (15% European) there was little difference between country of birth and racial origin.
All RRT patients who survived 90 days,
ANZDATA Registry, ANZSN 2003

10. Incidence by country of birth.4 .6 .8 1
Rate ratio
15-44
45-64
65 & over
Age (years)
1.2
1.4 .5 .7 .9
1.5 2
2.5 3
British Isles
S. Europe
Rest of Europe
Mid East
Indian sub-cont
East/SE Asia
ANZDATA Registry, ANZSN 2003

11. ANZDATA Registry, ANZSN 2003
Population
Australian population and Australian ESRD patients, , by country of birth
ANZDATA Registry, ANZSN 2003

12. ANZDATA Registry, ANZSN 2003
Specific diseases - 1
Glomerulonephritis in year group
Country of birth Rate ratio
British Isles [ ]
S.Europe [ ]
Rest of Europe [ ]
Middle Eastern [ ]
Indian subcontinent [ ]
East/SE Asia [ ]
Pacific Islands [ ]
The type of glomerulonephritis was also examined were sufficient numbers were available. Persons born in east/Southeast Asian and higher rates of mesangial IGA-related disease than the other three groups, and also an increase in Lupus nephritis. There was no difference, however, in focal sclerosing glomerulonephritis. In contrast, the Middle East-born groups had the highest rates of focal sclerosing glomerulonephritis, but not others. Southern Europe-born people had high rates of mesangial IgA. Interestingly, there were no cases of anti-GBM disease among people born in Southern Europe, any of the three Asian regions or Pacific island nations.
ANZDATA Registry, ANZSN 2003

13. ANZDATA Registry, ANZSN 2003
Specific diseases – 2
Hypertension / arteriopathic / renovascular disease among 65+ year group
Country of birth Rate ratio
British Isles 0.9 [ ]
S. Europe [ ]
Rest of Europe 1.0 [ ]
Middle Eastern 1.6 [ ]
Indian subcontinent 2.0 [ ]
East/SE Asia 1.5 [ ]
Do we know anything about the rates of hypertension among different subgroups in the Australian population.
ANZDATA Registry, ANZSN 2003

14. ANZDATA Registry, ANZSN 2003
Issues
Selection bias
ANZDATA only collects treated ESRD
Most applicable to older age group
Will change over time
Competing risks
Patients may now be surviving to end-stage whereas previously they did not
Lead-time bias
Lessening level of creatinine at entry
Effect on survival analyses
Changing demography
Progressive increase in proportion of populations of Asian / Aboriginal / Maori / PI racial origin
Progressive ageing of the population. \
ANZDATA Registry, ANZSN 2003

15. ANZDATA Registry, ANZSN 2003
Issues 2
Classification bias
Is the increase in type 1 diabetes actually type 2 in young people?
Changes in disease prevalence
Increasing population prevalence of diabetes
Changes in disease behaviours
?beneficial effect of treatments
ACE inhibitors may reduce the number of diabetics reaching end-stage
But they may also affect the competing risk of cardiovascular disease
ANZDATA Registry, ANZSN 2003

16. ANZDATA Registry, ANZSN 2003
Where to?
More detailed examination of trends in recent years, and types of GN
Comparison of these changes with elsewhere
Hence the 90 day exclusion
Associations with different treatment patterns
ANZDATA Registry, ANZSN 2003

17. ANZDATA Registry, ANZSN 2003
Acknowledgements
All staff of contributing renal units
ANZDATA staff
Sheila Williams
ANZDATA Registry, ANZSN 2003

18. ANZDATA Registry, ANZSN 2003
ANZDATA Registry, ANZSN 2003