In response to Stephen Black's rapid response (ref 1) , I am surprised to be accused of misleading but again other readers are welcome to make their own conclusion reading my response (ref 2). However, he asserted that I had ignored "the much better Canadian study that shows a clear relationship between total time in ED and mortality"; I did no such thing. I have never disputed the observation that the longer the admitted patient spent in ED the higher the inpatient mortality rate for admission via emergency; I had however previously pointed out access block (as a main cause of ED delays and overcrowding) is more likely a reflection of a overcrowded hospital which is dangerous for any patient (ref 3).
Stephen Black has "worked as consultant to several health organisations on the performance of A&E departments and the 4hr target", but he may not know that while an occurrence is closely associated with an outcome, bringing in an intervention to reduce this occurrence does not mean the outcome is reduced.
The classic example is the CAST study (ref 4): patients who suffer from myocardial infarctions (MIs) have a high risk of sudden death (outcome), presumably due to arrhythmia (occurrence). Antiarrhythmics (intervention) successfully reduced the amount of PVCs, but consequently led to more arrhythmia-related deaths. Similarly arthroscopic knee surgery (intervention) specifically addressing degenerative knee arthritis and mensical tears (occurrence) does not resolve the knee pain (outcome) attributed to the arthritis (ref 5). And it is a fact that the 4-hour target had failed to demonstrate reduced mortality resulting from its implementation in the NHS.
Stephen Black and Drs Boyle and Higginson should also have realised that there is strong Australian research (ref 6, 7, as well as being referenced by Boyle and Higginson themselves) that achieving the 4-hour target is not required to improve inpatient mortality rate; compelling evidence suggests a range of 60-80% compliance to the 4 hour threshold can achieve maximum reduction of mortality rates, whereas the mortality rate sharply increase as compliance to 4 hour threshold head towards 90% and beyond (ie the 4-hour target).
Let me be clear on this: the 4-hour-target for the NHS is achieving 90-98% compliance of emergency department (ED) visits where door-to-departure (discharge or admission) occurred within the time-frame of less than 4 hours.
So far in my previous and current response, I have pointed out that:
- Excessive resources has been focussed on getting the patients out of ED within a time frame while inpatient beds and services are cut or frozen.
- Reduction in inpatient mortality can be obtained without the achieving the 4 hour target, by as little as 60% compliance or extending the 4 hour limit
- The quest to achieve the target has resulted in increased admission rates and creative managerial accounting to comply with the directive, hence contributing to the appearance of reduced mortality rates.
Inpatient mortality rates are (of course) the proportion of inpatient death out of all inpatient admission over a defined timeframe. Any 12 year old can tell you to reduce the rate, you either reduce the number of deaths or increase the admission numbers, the latter being a consistent observation of time-based target implementation across the globe.
These supporters of 4-hour target may claim we are talking about the same thing; I doubt so. While I am unable to change their steadfast defence of an arbituary target of 4 hours that has not resulted in reduced mortality rates in the NHS, I hope other BMJ readers will be open to ideas that may achieve similar results at less cost, by accepting alternative time targets (5 hours, for example, as suggested by Dr Campbell - ref 8) and improving hospital systems as a whole.
Certainly this chain of rapid responses has vindicated my use of the title "smoke and mirrors" to describe the tactics of some supporters of the 4 hour target (ref 9).
Rapid Response:
More misleading claims? Again, not by me
Dear Editors
In response to Stephen Black's rapid response (ref 1) , I am surprised to be accused of misleading but again other readers are welcome to make their own conclusion reading my response (ref 2). However, he asserted that I had ignored "the much better Canadian study that shows a clear relationship between total time in ED and mortality"; I did no such thing. I have never disputed the observation that the longer the admitted patient spent in ED the higher the inpatient mortality rate for admission via emergency; I had however previously pointed out access block (as a main cause of ED delays and overcrowding) is more likely a reflection of a overcrowded hospital which is dangerous for any patient (ref 3).
Stephen Black has "worked as consultant to several health organisations on the performance of A&E departments and the 4hr target", but he may not know that while an occurrence is closely associated with an outcome, bringing in an intervention to reduce this occurrence does not mean the outcome is reduced.
The classic example is the CAST study (ref 4): patients who suffer from myocardial infarctions (MIs) have a high risk of sudden death (outcome), presumably due to arrhythmia (occurrence). Antiarrhythmics (intervention) successfully reduced the amount of PVCs, but consequently led to more arrhythmia-related deaths. Similarly arthroscopic knee surgery (intervention) specifically addressing degenerative knee arthritis and mensical tears (occurrence) does not resolve the knee pain (outcome) attributed to the arthritis (ref 5). And it is a fact that the 4-hour target had failed to demonstrate reduced mortality resulting from its implementation in the NHS.
Stephen Black and Drs Boyle and Higginson should also have realised that there is strong Australian research (ref 6, 7, as well as being referenced by Boyle and Higginson themselves) that achieving the 4-hour target is not required to improve inpatient mortality rate; compelling evidence suggests a range of 60-80% compliance to the 4 hour threshold can achieve maximum reduction of mortality rates, whereas the mortality rate sharply increase as compliance to 4 hour threshold head towards 90% and beyond (ie the 4-hour target).
Let me be clear on this: the 4-hour-target for the NHS is achieving 90-98% compliance of emergency department (ED) visits where door-to-departure (discharge or admission) occurred within the time-frame of less than 4 hours.
So far in my previous and current response, I have pointed out that:
- Excessive resources has been focussed on getting the patients out of ED within a time frame while inpatient beds and services are cut or frozen.
- Reduction in inpatient mortality can be obtained without the achieving the 4 hour target, by as little as 60% compliance or extending the 4 hour limit
- The quest to achieve the target has resulted in increased admission rates and creative managerial accounting to comply with the directive, hence contributing to the appearance of reduced mortality rates.
Inpatient mortality rates are (of course) the proportion of inpatient death out of all inpatient admission over a defined timeframe. Any 12 year old can tell you to reduce the rate, you either reduce the number of deaths or increase the admission numbers, the latter being a consistent observation of time-based target implementation across the globe.
These supporters of 4-hour target may claim we are talking about the same thing; I doubt so. While I am unable to change their steadfast defence of an arbituary target of 4 hours that has not resulted in reduced mortality rates in the NHS, I hope other BMJ readers will be open to ideas that may achieve similar results at less cost, by accepting alternative time targets (5 hours, for example, as suggested by Dr Campbell - ref 8) and improving hospital systems as a whole.
Certainly this chain of rapid responses has vindicated my use of the title "smoke and mirrors" to describe the tactics of some supporters of the 4 hour target (ref 9).
References
1. http://www.bmj.com/content/359/bmj.j4857/rr-9
2. http://www.bmj.com/content/359/bmj.j4857/rr-5
3. Goh S. Emergency department overcrowding and mortality after the introduction of the 4-hour rule in Western Australia. Med J Aust 2012; 197 (3): 148. doi: 10.5694/mja12.10828
4. https://en.wikipedia.org/wiki/Cardiac_Arrhythmia_Suppression_Trial
5. http://www.bmj.com/content/357/bmj.j1982
6. Sullivan C, Staib A, Khanna S, et al. The national emergency access target (NEAT) and the 4-hour rule: time to review the target. Med J Aust 2016;359:354. doi:10.5694/mja15. 01177. pmid:27169971.
7. Staib A, Sullivan C, Griffin B, Bell A, Scott I. Report on the 4-h rule and national emergency access target (NEAT) in Australia: time to review. Aust Health Rev 2016;359:319-23. doi: 10.1071/AH15071 pmid:26433943.
8. https://doi.org/10.1136/bmj.j4857
9. http://www.bmj.com/content/359/bmj.j4857/rr-5
Competing interests: No competing interests