The effect of organisational factors and processes of care on between centre achievement of audit measures for calcium, phosphate and PTH in UK
haemodialysis centres
A Hodsman*, A Casula, J Gilg, Y Ben-Shlomo, P Roderick,
C Tomson
Introduction to the ‘centre effect’• Theoretical
– ‘Ecological epidemiology’ – Hierarchical data structures
• Pupils in schools• Patients in hospitals
• Practical– Identify best practices from ‘high performers’– Determine the ‘value added’– Improve quality and equity of healthcare
The ‘centre effect’ and the UKRR
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Upper 95% confidence interval
% with P04 < 1.8mmol/L
Lower 95% confidence intervalN = 17,319
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Number of patients in unit%
P0
4≤
1.8
mm
ol/L
% with phosphate <1.8mmol/L
Lower 99.9% CI
Upper 99.9% CI
Lower 95% CI
Upper 95% CI
Mean
Proportion of HD patients with phosphate <1.8mmol/L in each dialysis centre in England, Wales and Northern Ireland
Change in mean phosphate before and after case mix adjustment using multi level analysis (MLWin)
UnadjustedAdjusted for age, gender, ethnicity,
predialysis creatinine, transplant WL status
Poster 0097, Wednesday 22nd 1pm
Methods
• Cohort– Prevalent HD cohort 2007
• Exposure variables– Structural characteristics,organisational and clinical
processes
• Outcome variables– Mean centre phosphate, calcium and PTH– Proportion in centre with
• Phosphate<1.8mmol/L,Calcium 2.2-2.6 mmol/L, PTH 16-32 pmol/L
• Confounders– Patient level case mix differences
Exposure variables
• Literature search of all clinical practice guidelines for management of calcium, phosphate and PTH
• Qualitative pilot study in 6 dialysis centres
• ‘Semi structured’ interviews with MDT
• Final questionnaire sent to 56 centres
• Derived 30 possible indicators
Statistical model
• Binary or categorical variables
• Linear and logistic regression (Stata)
• Univariable model with a clustering term
• Adjusted for age, gender, ethnicity and predialysis creatinine
• Identified an interaction between gender and predialysis creatinine
System of care
1. Consultant• Single physician responsible for long term care and
monthly Quality Assurance (QA) at ANY dialysis location (main or satellite)
2. Centre• Single physician responsible for all patients (long
term care and QA) in ONE dialysis location (main or satellite)
3. Mixed• Different physicians responsible for long term care
and monthly QA at any dialysis location (main or satellite)
Phosphate
Variable
OR for Phosphate <1.8mmol/L
Unadjusted Adjusted
WTE Nephrologists 1.16 1.14
WTE Dietitians 1.12 1.08
WTE Pharmacists 1.11 1.05
Intensity of audit 0.92 0.83
System of Care - Consultant 1.13 1.09
System of Care - Centre 1.27 1.23
QA score - Some MDT 1.34 1.17
QA score - All MDT 1.47 1.27
Proforma 1.23 1.12
Intensity of nephrology review 1.14 1.14
Intensity of dietitian review 1.1 1
Intensity of pharmacist review 1.12 0.92
Intensity of nurse input 0.88 0.96
Intensity of feedback 1.04 1.06
Trigger phosphate 1.07 1.12
Target high risk 1 0.9
p<0.01 p<0.05
Variable
OR for Phosphate <1.8mmol/L
Unadjusted Adjusted
Policy for Cinacalcet - Protocol 0.83 1.05
Policy for Cinacalcet - Unrestricted 0.88 1
Policy for Lanthanum - Protocol 0.97 1.09
Policy for Lanthanum - Unrestricted 0.87 0.89
Hosp supply Al, Ca binders/Vit D 0.96 0.83
Hosp supply Cinacalcet/Lanthanum 0.92 0.87
Additional Prescribers 0.97 1
WTE PTX surgeons 0.95 1.06
Guideline 1.14 1.04
Guideline-phosphate binders 1.12 1.02
Guideline-Cinacalcet 1.17 1.07
Guideline-dialysate Ca 1.16 1.27
Guideline-parathyroiectomy referral 1.1 1.06
Measure bloods as per RA 1.17 1.14
Use of low Ca dialysate 1.17 1.14
Calcium
Variable
OR for calcium 2.2-2.6mmol/L
Unadjusted Adjusted
WTE Nephrologists 0.91 0.9
WTE Dietitians 1.2 1.15
WTE Pharmacists 0.98 1
Intensity of audit 0.9 0.9
System of Care - Consultant 0.82 0.8
System of Care - Centre 0.95 1
QA score - Some MDT 0.87 0.89
QA score - All MDT 0.96 1.02
Proforma 1.01 1
Intensity of nephrology review 1.15 1.03
Intensity of dietitian review 0.65 0.67
Intensity of pharmacist review 0.9 0.96
Intensity of nurse input 0.96 0.97
Intensity of feedback 0.97 0.95
Trigger phosphate 1.3 1.29
Target high risk 0.78 0.81
p<0.01 p<0.05
Variable
OR for calcium 2.2-2.6mmol/L
Unadjusted Adjusted
Policy for Cinacalcet - Protocol 1.44 1.36
Policy for Cinacalcet - Unrestricted 1.02 1.04
Policy for Lanthanum - Protocol 1.5 1.44
Policy for Lanthanum - Unrestricted 1.32 1.32
Hosp supply Al, Ca binders/Vit D 1.04 1.08
Hosp supply Cinacalcet/Lanthanum 1.02 1.09
Additional Prescribers 0.9 0.93
WTE PTX surgeons 1.37 1.31
Guideline 0.85 0.9
Guideline-phosphate binders 0.86 0.93
Guideline-Cinacalcet 1.18 1.15
Guideline-dialysate Ca 1.08 1.05
Guideline-parathyroiectomy referral 0.98 1.02
Measure bloods as per RA 0.98 1.04
Use of low Ca dialysate 0.89 0.94
PTH
Variable
OR for PTH 16-32mmol/L
Unadjusted Adjusted
WTE Nephrologists 1.02 0.98
WTE Dietitians 1.23 1.2
WTE Pharmacists 1.08 1.09
Intensity of audit 0.93 0.91
System of Care - Consultant 0.98 0.96
System of Care - Centre 1.01 1.01
QA score - Some MDT 1.06 1.04
QA score - All MDT 1.1 1.09
Proforma 1.04 1
Intensity of nephrology review 1.16 1.15
Intensity of dietitian review 0.99 0.98
Intensity of pharmacist review 1.12 1.11
Intensity of nurse input 0.8 0.84
Intensity of feedback 0.83 0.82
Trigger phosphate 1.06 1.07
Target high risk 0.99 0.99
p<0.01 p<0.05
Variable
OR for PTH 16-32mmol/L
Unadjusted Adjusted
Policy for Cinacalcet - Protocol 0.94 0.96
Policy for Cinacalcet - Unrestricted 0.79 0.83
Policy for Lanthanum - Protocol 0.91 0.9
Policy for Lanthanum - Unrestricted 0.99 0.98
Hosp supply Al, Ca binders/Vit D 1.07 1.06
Hosp supply Cinacalcet/Lanthanum 1.13 1.14
Additional Prescribers 0.88 0.9
WTE PTX surgeons 1.14 1.15
Guideline 1.1 1.1
Guideline-phosphate binders 1.1 1.1
Guideline-Cinacalcet 1.04 1.05
Guideline-dialysate Ca 1.03 1.02
Guideline-parathyroiectomy referral 1.04 1.02
Measure bloods as per RA 1.06 1.05
Use of low Ca dialysate 0.9 0.9
Summary of results
• Better phosphate control in centres is associated with– System of care– Number of MDT attending QA meetings
• Better calcium control in centres is associated with– Policy for prescribing cinacalet and lanthanum– High WTE parathyroidectomy surgeons
Further analysis
• Multivariable model Multilevel model (MLWin)– Ideal model– % of between centre
variation attributable to:• Patient level/Case mix
• Centre level/Structure and process
– Limited number of exposure variables due to possible interactions
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Fig 5.1a: Simple Regression line
Fig 5.1b: Regression lines with variable intercepts
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Fig 5.1c:Regression lines with variable slopes and intercepts
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Fig 5.1d:Multi level model (2 levels) with variable slopes and intercepts
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Further work
• Quality improvement project– Collaborative work to test implementing
practices associated with better outcomes for calcium, phosphate and PTH
• Methodological work– Improve the UKRR methodology to compare
centre performance of quality indicators
Acknowledgments
• Multidisciplinary teams in UK Dialysis Centres
• UK Renal Registry– Dr J Gilg, Dr A Casula
• PhD Supervisors– Dr C Tomson, Prof P Roderick,
Prof Y BenShlomo