Yossarian, Bologna and the NHS

Yossarian, Bologna and mortality coding

 There are still some deniers who are backing the HSMR methodology, despite the many criticisms by academics about the limitations of the method. In particular, members of Cure the NHS claim this is all part of a denial mechanism. All this reminds me of Catch-22.

In Joseph Heller's famous war novel, bombardier Yossarian and his squadron dread their missions over Bologna. So in the middle of the night Yossarian moves the bombline. In the morning there is great relief from the squadron that they don't have to fly over an enemy-held Bologna any more.

Of course the reality is that they still do. The bombline did not reflect reality. So to insist that the reality was what the bombline said would be insane. But this is what Cure the NHS are doing in effect. They insist that the people that state that the HSMR does not reflect the actual mortality rates are denying reality. But they are the people who are fooled by Yossarian.

Who committed the murders, "Donna" or "Doug"

Who committed the murders, "Donna" or "Doug"

In an interesting take on psychological continuity,

A transgender woman accused of being a serial killer is blaming the 1990 murders of three prostitutes in Washington State on Douglas Perry, the person she identified as before her transition.

Donna Perry, 62, told police in 2012 in an affidavit filed in Spokane Superior Court that she had gender reassignment surgery in Thailand, and when a person transitions from male to female, "there's a great downturn in violence." 

from ABC Newshttp://abcnews.go.com/Health/transgender-woman-male-persona-serial-killer/story?id=22959423

There has been argument about psychological continuity with dissociative identity disorder (DID), aka multiple personality disorder, especially when the personality of the alters is dramatically different and there is amnesia for the actions of the alters. Should one "person" be punished for the actions of another "person" who just happens to live in the same body?

None of these arguments can be applied to this situation. A more apt analogy might be a man in his 60s being punished for crimes committed in his foolish youth. The punishment might be reduced in the circumstances, but the person is still held responsible (unless there is a statutory limitation).

Screening, case finding and diagnosis

Screening, case finding and diagnosis

The tragic case of Sophie Jones has been reported in the press this week. This young woman died from cervical cancer at the age of 19. She had apparently requested a 'smear test', but was refused as she did not fit the criteria for the national screening programme. I do not know the precise way that request was framed, nor what relationship that request had with her abdominal symptoms, attributed to Crohn's disease. Nor are we told the timing of the request. Whether or not the smear test would have affected the outcome is impossible to know from the newspaper stories.
This case does illustrate the widespread confusion between screening, case finding and diagnostic testing. Screening tests are applied to entire sections of the population who are asymptomatic. Thus there are strict criteria applied to avoid causing more harm than benefit. There was also cost considerations. Screening programmes are not a replacement for diagnostic tests. If a woman has a problem with her breast between screening mammograms, she should go through the standard diagnostic workup. Similarly if a woman has symptoms or signs suggestive of cervical cancer. Statistics that apply to the asymptomatic population should not be applied to the symptomatic population. It is however worth pointing that deaths from cervical cancer across the entire population in this age group are very rare.
Case finding is the application of testing in a sample of the population selected on the basis of risk factors for a disease, for example a relevant family history.
Diagnostic testing is applied on the basis of relevant history, signs or symptoms.
It might be that diagnostic testing was indicated here at the time Sophie Jones asked for a smear. It might be that there was no reason to perform a smear test at that time. Either way, this case does not indicate a need to expand the screening programme - merely a need to consider diagnostic testing even when screening is not indicated. This is an unfortunate side-effect of screening, that it may lead to a rejection of appropriate testing - either through the false reassurance of a recent negative test, or the incorrect estimation of the likelihood of disease in someone ineligible for screening.

"Shooting the messenger stats"

"Shooting the messenger stats"

In an article in the Daily Mail, the zombie statistic rears its ugly head again:

around 1,200 patients died due to failings at the trust under his management 


The article is littered with inaccuracies - Mid Staffs not under his management, for example - and seems to be a vehicle for the Daily Mail and Julie Bailey's joint vendetta against a man who is as the article states about to retire. 

I asked the developer of the statistic being quoted for his comment on this misuse of the HSMR (which he has apparently tried his best to stop), and his reply was frankly bizarre:

 

BrianJarman‏@Jarmann

No comment, except no one held to account (but big efforts to shoot the messenger stats)

The metaphor of "shooting the messenger" is well known, but not "shoot the messenger stats". It doesn't really work - the stats ARE the message, so is Brian Jarman really saying "shoot the message"? 

The HSMR methodology has come under great scrutiny and has been criticized by many eminent statisticians and other heathcare experts. Prof Sir Brian Jarman should be addressing these in the academic sphere to demonstrate his faith in the methodology, rather than respond with an ad hominem argument.

Airlines the paragon of virtue on safety?

Airlines the paragon of virtue on safety?

It's common for certainly amateur commentators on patient safety to say that since airlines wouldn't fly without the correct number of crew, wards that are understaffed should be shut (although unlike aircraft, no one can put an exact figure on the minimum number of staff in a particular ward). This is such a ridiculous notion, it doesn't warrant too much time analysing it - it's not as if these wards can eject their patients the moment they are one member of staff down. It's also not a valid comparison, like for like.

Why is this? The cost-critical aspects of commercial aviation are space and fuel, not staff. This is not the case with healthcare, with staffing the major cost. Space is at a premium in an aircraft - we all know how cramped it is in economy. However, does this have a safety implication? Yes, it does - the risk of a deep vein thrombosis and subsequent pulmonary embolism is now well recognized. The magnitude of these risks were suppressed in the early days by airlines. The other main cost is fuel, which largely reflects the weight of the aircraft (for a given aircraft) and we all know that excess baggage is expensive, and this is because it requires extra fuel. The precise amount of fuel is calculated so that there is no excess weight. Of course there is a margin built in case of a diversion, but still that margin is not massive. 

Knowing that weight and fuel economy are crucial, we understand why expense on hi-tech materials in aircraft make big savings in the long term. Likewise, the NHS should be investing in technology that frees up staff for the important tasks by reducing paperwork where possible.