Outcomes in AKI, the national audit Dr K A Abraham Aintree University Hospitals

AIMS Study the provision of renal services across the country Ascertain workload Study outcomes for different categories of renal disease Provide user friendly data to clinicians, without adding to their work

Hospital Episode Statistics for Physicians Renal Reference Group KA Abraham/ Jan 09

Methods - 1 HES data, All Trusts in England. 06 – 07 & 07 - 08 Acute Trusts ICD Code Algorithms 3 Renal Streams – AKI, CKD, RRT Emergency Medical Admissions

Coding Algorithm Acute Renal failure [Acute Kidney Injury]: AKI Codes: A985, D596, K767, N170 – 179, N990, O084, O904 Electrolyte imbalances associated with AKI: E870 - Hyperosmolality & hypernatraemia E875 – Hyperkalaemia N251 - Nephrogenic diabetes insipidus Renal replacement Codes: X401 – 406, 408, 409

AKI Algorithm – ICD10 List of AKI diagnoses - A List of clinical conditions likely to be associated with AKI - B Definite AKI = A in Coding position 1 Probable AKI = A in Coding position 2 – 7 & B in position 1 Possible AKI = A in Coding position 2 – 7 but No B diagnosis in position 1

Methods - 2 3 classes of Trusts – Transplant, Onsite, Visiting Linked to Office of National Statistics Pilot in 4 renal networks – 16 trusts Validated by clinicians from each network National roll out for year 1 Analyses sent out to all nephrologists Feedback incorporated into 2 year analysis.

Statistics SPSS (v16) Unpaired t tests or Chi squared tests as appropriate 30 day mortality using the ONS death data linked to the HES data Corrected for a variety of known confounders. Age is non-linearly related to mortality, so corrections were performed by comparing each 5 year age band in each trust with the national mortality for that age band with look up tables. Corrections also for index of multiple deprivations Co-morbidity variable using Charlson index.

Weaknesses CODING – Variation, Depth, Accuracy Unaccounted Variables - Consultations Interactions of Factors

Validation Multiple logistic regression used to compare mortality risk using age, co morbidity, deprivation, and specialty of physician The data was re run a) excluding patients transferred between units and b) for only patients with an ICD 10 code of N179 that carries the descriptor of “acute renal failure - unspecified”. Excluded “possible AKI” analysed.

Results AKI Incidence = 1·34% of all emergency admissions. [61,739 of 4,637,488] Only half would have been identified if only the first diagnosis listed had been used. The numbers & types of AKI cases were similar in all trusts, regardless of the service available. Thirty day mortality was 30·0%. More than half the acute hospitals did not have on site renal specialists [55%]

Baseline Comparisons Transplant Onsite Visiting Admissions. 18121 16674 11652* % AKI. 1.5 1.3 Age in yrs 71.9 75.1 76.2* Codes 5.9 5.8 Comorbidity 1.1 Deprivation. 12663 15800 15127 Specialists 10.7 4.0 0* Discharges%. 26.9 19.9** * p < 0.001 separate or combined. ** p < 0.05 between T & O units

AKI Outcomes * * ** * * p < 0.001 separate & combined. ** p < 0.001 V to T only

AKI Outcomes Transplant [21] Onsite [47] Visiting [82] Median dialysed % 9.6 4.3 1.3* Median LOS in days 15.7 14.2 13.7** Median mortality unadjusted [30d] 23.8 28.4** 33.0* Median mortality adjusted [30d] % 25.3 29.4** 32.5* * p < 0.001 separate or combined. ** p < 0.05 between T & O units

Inter Hospital Transfers 13·7% of admissions to T and 5·7% to O. Transfer patients were younger - mean age 64 vs. 73 years Did a selection bias lead to better results? Within centre, no significant differences in the outcomes between transfer and direct patients Significant mortality differences persisted when transfers excluded

Adjusted Mortality & Renal Cover

AKI Mortality Vs Nephrologists in SHA London All other SHA’s Population 7,443,379 44,021,267 AKI No. /pmp 1260 1189 Mean age (yrs) 73.5 75.4 Mean No. Dx codes 5.9 5.8 Mean co-morbidity score 1.05 1.07 Mean deprivation score 13400 15193 No. nephrologists/ pmp 11.4 6.1* Adjusted mortality (%) 26 31.2* * p < 0.001

Do nephrologists make a difference? % Deaths % Renal

Conclusions AKI is not rare AKI is deadly Specialist renal care is associated with better AKI outcomes A substantial majority do not receive specialist care Models for better provision have to be considered similar to acute diabetes worse than MI or COPD

What can we do better? EDUCATION Spoke unit cover Rapid Response CIN Prophylaxis AKI Guidance What can we do better? Region wide IT EDUCATION Clerking proforma AKI Flag ITU Liaison Transfer Protocols

Thank You. M Pearson, E Thompson, K Bodger, AHOP Jane MacDonald, Afzal Chaudhry, Donal O’Donoghue, Charlie Tomson, Kevin Harris, Gary Cook, James Hollinshead, Melanie Maxwell NHS IC K. A. Abraham, UHA.