CRAB – Retrospective Clinical Audit – Identifying and investigating real performance issues

CRAB helps hospitals identify and resolve issues relating to avoidable harm and mortality.

  • Accurate identification of issues (rather than false positives) as our system adjusts for each individual patient’s physiology and pre-existing conditions as well as any procedural risk
  • Demonstrable reductions in avoidable harm and mortality
  • Significant savings per hospital (identified average $3m per annum) just on the direct cost of caring for patients that have suffered avoidable harm
  • 10% reduction on complaints/clinical negligence claims
  • Fast indication of problems (as quickly as four weeks to allow for considering readmissions within 30 days)
  • Help for hospitals to recognise there is a real issue and then drill-down to the root cause

Reporting to identify real issues and demonstrably reduce avoidable harm and mortality

Our system shows specialties that are doing well (to help share that best practice) and ones that are doing badly relative to the actual health, physiology and mix of existing triggers of every patient they have treated.

Other systems would report hospital’s headline results against an average value from other hospitals – essentially ignoring the actual mix of patients, their health and existing complications.

Clinicians and managers can drill down into the information we report whenever they want – from high level (hospital performance), specialties level, consultant level and finally down to individual patient information.

Worse than expected performance (red traffic lights) show where results are way below what is expected with the specific mix of patients and their complications etc.  Exceptional performance is also highlighted to help hospitals share best practice.

Our unique results can be accessed by interrogation of our system directly down to the individual patient coding level or via reports that highlight rolling performance within the hospital, issues, dominant complications, specialties performing well or badly, consultant level performance (where appropriate) and approaches to improving the situation.

Why typical Business Information systems cannot deliver what we do

Why do hospitals try to diagnose their own care and safety for patients by using BI systems to look at their averaged performance for mortality against other hospitals?  This ignores the mix of patients they are treating and leads to false positive alerts (up to 95% in one case) and the wasting of time trying to track down problems that don’t exist.  Clinicians rapidly lose faith in the results and hospitals fail to have an objective measure of their own performance for the mix and complexity of patients they have seen (as shown below). 

Why we are different

We use sophisticated and validated algorithms to accurately risk adjust for each patient and provide observed to expected results for surgical patients and quality of care assessments for medical patients.  These have been judged independently to be 4 times more accurate than any other methodology.

We consider all patients in the hospital looking at all their diagnoses, 32 triggers, 146 surgical conditions and the vast majority of procedures.

Our reporting is 30 days after discharge to allow for readmission and has been tailored to correctly consider mortality post-discharge, assessment with multiple readmissions etc.

This approach is based on 30 years research by our CMO and has been validated using our unique referential database of 120 million patient records from 46 countries, more than 300 hospitals and our clients across 11 countries including the US and UK.

Tracking avoidable harms accurately

Surgical operations tend to be well defined, with reasonably clear outcomes, but it is much more difficult to measure the quality of medical care.

Medical patients may suffer from a range of long-term conditions that will affect their state of health over a number of years with no end point.

They may be treated by a number of different physicians over time, or at the same time. So how can you measure the quality of medical care?

The CRAB Medical module is the only system to produce automated tracking of the indicators of avoidable harm based around 32 trigger types to assess the quality of front-line care across an organisation. 

We do not use a simple comparison of the outcomes for deteriorating patients between one hospital and a statistical average.

Our approach provides a sophisticated and validated consideration of how the hospital has done with the individual patients and their unique state of health etc.

The results add real value for physicians as well as the wider organisation.

What are triggers and how do we use them to risk adjust for individuals?

Triggers are events during a patient’s hospital stay that may have resulted from hospital-based ‘harm’. The Medical Module assesses every in-patient admission using clinical coding to identify validated surrogates that map to these trigger events.

In many such cases there are direct coding relationships, but in others complex combinations of clinical codes with the process of episodes of care are used to identify the trigger.

The triggers are combined into modules: general, surgical, intensive care, medication and laboratory tests, and investigation is possible by department, specialty and individual consultant.

C2-Ai has built up norms within CRAB for all triggers and combinations of triggers with our knowledge of changes in these indicators. With known individual clinician and institutional-based anomalies it is possible to identify variations in triggers which can be associated with potential deteriorations in practice and hence outcome.

Data can also be interrogated using physiological profiling to understand the inherent state of health of the patients treated and any underlying diagnoses that may be a cause of complications. Reporting can be supplemented, where appropriate, with key audit criteria for effective care.

CRAB has provided data for the consultants to really understand their outcomes for patients in a user friendly way.”

Alison Diamond
Medical Director, Nothern Devon Healthcare NHS Trust

Examples of report outputs of hospital performance on care quality and key triggers

Fair, unbiased analysis of surgical outcomes

It is imperative – for patients and surgeons alike – that measures of quality are properly adjusted for the individual conditions of the patients receiving treatment and the complexity of the care involved.  CRAB is unique in calculating the risk for every patient as an individual rather than making assumptions about patients from national statistics.

The CRAB Surgery module is the result of thirty years of research and development, and evolves beyond the POSSUM audit methodology, published by our CMO Graham Copeland et al in 1991 and in use around the world.  The original POSSUM methodology is recommended by the Royal College of Surgeons and the National Confidential Enquiry into Perioperative Deaths (NCEPOD), but we have developed it significantly 



Demonstrable reduction in avoidable harm 

Demonstrable reduction in mortality

Targets improvement efforts to right areas

Demonstrable performance and improvement tracking

Fewer readmissions

Properly risk-adjusted stats mean surgeons no longer ducking high risk ops for fear of “screwing up” their stats

Evidence to use with regulatory authorities (e.g. CQC) potentially leading to improved ratings

Better rankings

Benchmarked performance against our unique global patient set


Significant savings on treatments and care related to avoidable harm (e.g. £2.3m per annum possible – average across three UK hospitals)

Lower complaints & clinical negligence claims (down ~10%)

Reduced legal costs 

Reduction in cost per treatment and variations

Lower readmission rates (which are subject to financial penalties in a number of countries)

RoI on our system 30 – 40x

Option to deploy at zero up front cost and % share of savings identified

Lower variability in treatment costs 

Reduction in insurance premiums – at individual practitioner and hospital level

Higher margins against fixed price per treatment 


Better use of resources due to reduction in beds blocked (esp. critical care) through additional, avoidable care and readmissions

More effective use of resources in the hospital by avoiding harms

Less management overhead used up fixing issues and dealing with problems.

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