U.P.Udayaraj 1 , P.Roderick 2 , R.Steenkamp 1 , C.Tomson 1,3 , D.Ansell 1 , F.Caskey 3

1. Renal Association UK Renal Registry Effect of Social deprivation on achievement of clinical performance targets in dialysis patients – Confounding by ethnicity and co-morbidity? U.P.Udayaraj1, P.Roderick 2, R.Steenkamp 1, C.Tomson1,3, D.Ansell 1, F.Caskey 3 1UK Renal Registry, 2 Public health Sciences, University of Southampton, 3 Southmead Hospital, Bristol

2. Renal Association UK Renal Registry Introduction • Equity – core ethical principle of NHS • In the USA,‘inequity’ due to socio economic status well described in CKD patients • In the UK, variation in health outcomes according to social deprivation (SD) well reported in non-renal disciplines • Very few studies on CKD patients in the UK • SD associated with: • increased adjusted mortality on renal replacement therapy but accounted for by increased co-morbidity † • differences in attainment of performance targets in univariate analysis † † Caskey et al KI 2006;70:2134- 40

3. Renal Association UK Renal Registry Aims To examine if poorer attainment of clinical performance targets in socially deprived patients on dialysis could be explained by differences in patient case mix

4. Renal Association UK Renal Registry Methods (1) • Incident RRT patients 1997-2004 in England & Wales • Inclusion criteria • From centres with >85% ethnicity returns (no survival bias†) • Age >18 years • Survived 1st year of RRT • Exclusion criteria • Missing data on age/gender/PRD/ethnicity/address • Transplant in the 1st year † Caskey et al KI 2006;70:2134- 40

5. Renal Association UK Renal Registry Methods (2) • Measurement of clinical performance targets • Lab values in the 4th /5th quarter ( at 1 year) of RRT included • RA standards 2002 • Hb  10 g/dl • URR > 65 % • Corrected calcium 2.2 –2.6 mmol/L • Phosphate < 1.8 mmol/L • Ca x Po4 < 4.4 mmol2/L2 (KDOQI) • iPTH < 32 pmol/L

6. Renal Association UK Renal Registry Methods (3) • Measurement of social deprivation • Townsend score calculated from 2001 census output area • % unemployed • % households overcrowded • % households with no car • % households not owner occupied • Patient’s postcode matched to output area • General population postcodes divided into Townsend quintiles (TQ) – quintile 5 being most deprived

7. Renal Association UK Renal Registry Methods (4) • Statistical analysis • Univariate analysis • % patients achieving standards across TQ • Chi-squared test , Cochrane- Armitage test (trend) • Multivariate analysis using sequential logistic regression models adjusting for • age & gender • cause of renal failure (PRD) • centre variability • dialysis modality • ethnicity • co-morbidity (only patients from centres with > 85% co-morbidity data included in this model)

8. Renal Association UK Renal Registry Baseline Characteristics

9. Baseline Characteristics - ethnicity P value <0.0001 P trend <0.0001

10. Renal Association UK Renal Registry Baseline Characteristics – co-morbidity

11. Renal Association UK Renal Registry Attainment of standards by social deprivation groups – univariate analysis * HD patients only, n=5562

12. Logistic regression models for attainment of Haemoglobin standard Adjusting for: Age, gender, PRD, centre, dialysis p=n.s. Prev model + ethnicity p=n.s. Prev model + co-morb p=n.s. p=0.001

13. Logistic regression models for attainment of iPTH standard Adjusting for: Age, gender, PRD, Centre, dialysis p=0.03 Prev model + ethnicity p=n.s. Prev model + co-morb p=n.s. p=0.002

14. Renal Association UK Renal Registry Subgroup analyses • Caucasians • univariate analysis • Lower attainment of Hb standard in TQ5 (p=0.01) • No difference in attainment of iPTH standard according to SD • multivariate analysis – no significant difference in either • Non Caucasians • univariate analysis • No difference in attainment of Hb standard according to SD • Lower attainment of iPTH standard in TQ 5 (p<0.01) • multivariate analysis – no significant difference in either

15. Renal Association UK Renal Registry Discussion • Differences in case-mix exist between SD groups • Ethnicity confounds SD analyses • Attainment of Hb and iPTH standards varies between SD groups in univariate analyses • Within the Caucasian cohort, SD was associated with lower attainment of the Hb standard • Within the non-Caucasian cohort, SD was associated with lower attainment of the iPTH standard • Differences in the attainment of standards seen in univariate analyses are no longer present when variation in case-mix is considered.

16. Renal Association UK Renal Registry Conclusions Variation in the attainment of some clinical performance targets observed in univariate analyses between SD groups appear to be explained by differences in patient case mix.

17. Renal Association UK Renal Registry Future work • Effect of social deprivation and ethnicity on other aspects of quality of care • Access to RRT • Access to renal transplantation • Outcomes on transplantation

19. Logistic regression models for attainment of Haemoglobin standard p=0.001 Prev model + age & gender p=0.008 Prev model + PRD p=0.03 Prev model + centre p=n.s. Prev model + dialysis p=n.s. Prev model + ethnicity p=n.s. Prev model + co-morb p=n.s.

20. Logistic regression models for attainment of iPTH standard p=0.002 Prev model + age & gender p=0.05 Prev model + PRD p=0.03 Prev model + centre p=n.s. Prev model + dialysis p=0.03 Prev model + ethnicity p=n.s. Prev model + co-morb p=n.s.