Luck

Let's ask the question again in a mathematical manner: Was our professor of hepatology doing urgent endoscopy more frequently than that expected by chance?

The calculation should be done like this:

• Let's assume there are x endoscopists on the list, each sharing the same number of call.
• For a defined period of observation, there are n urgent endoscopy request, and each of them is independent from another.
• For each urgent endoscopy, therefore, the probability of a particular endoscopist to be called would be 1/x; let's call this probability p (in other words, p = 1/x)

For example, if we have 5 endoscopists sharing the duty, the probability of being called for each one in a particular case would be 20% (i.e. 0.2). If, as suggested by VW, there are 100 urgent requests in one year, each endoscopist would be expected to be called around 20 times. (The statistical jargon is: this is the mean value.)

Now, here come the critical step: How many times would be too many to be expected by chance (or random distribution) ?

Simple. The allocation of event (of urgent request) to independent categories (i.e. endoscopists) follow the binomial distribution, and the calculation goes like this:

• For that one year and 100 endoscopy request, the variance of allocation is n × p × (1-p)
• The standard deviation (SD) is the square root of the variance, and
• the upper limit of expectation (i.e. 95% confidence interval) is 1.96 (or 2) times SD.

In this case, therefore, the variance is 100 × 0.2 × (1 - 0.2), i.e. 16; the standard deviation is 4. In other words, the maximum number of request that you would expect to encounter by chance during one year is 20 + 2 × 4, i.e. 28.

Lucky

For more than once my friend VW noted that he got the lion's share of emergency endoscopy. (See http://vwswong.blogspot.com/2011/08/unlucky.html for the most recent example.)

And, probably not by coincident, many of my outstanding colleagues also remark that they are particularly busy and unlucky (for them, but certainly lucky for our patients) while on emergency call. Some of us even conclude that there must be a higher power behind the clouds (or the curtain) who takes a close eye on us and manipulates the work load.

Of course our professor of hepatology is a scientist, and he goes on to review the situation by mathematical means. I must, however, say that he was not doing the calculation in the most meticulous manner, and, from what he showed, one could not conclude whether he was exceptionally poorly treated (or well-treated, as he tried to convince himself).

The problem could be examined in an entirely scientific manner.

Let me show you tomorrow.

PS. Of course you may not need to be too scientific. A knowledgeable doctor could pick up problems that an ordinary one miss; a responsible colleague generally would be more proactive and do things eagerly; and, above all, only those who know what they are doing would remember what happened during a call !

Year

In a recent incident, my colleague FP got a surprising question from the new bunch of third-year medical students: "Which year did you graduate?"

I must say the question was, as Bernard Woolley usually put it, entirely correct - literally, and the students were probably using it for really benign reasons (for example, out of admiration for seeing an apparently young doctor capable of teaching them).

Our surprise was, in contrast, a result of our crooked mind because adult physicians usually hardly ask their questions directly. For example:

• If we wish to know the year of graduation of another doctor, we would search from the Medical Council web site, or ask his colleagues.
• If we ask someone directly his year of graduation, we are not interested in the numerical answer - we just want to get at a better psychological position and start a fight with him.

However, it is also a wrong idea that senile professors do give better teaching to the students. More commonly it is quite the opposite. After all, who are the ones living on earth and know better the daily running of medical practice?

Byakuyako

My recent bedtime reading was Byakuyako (白夜行) of Keigo Higashino (東野圭吾).

The story was about a man, Ryoji Kirihara (桐原亮司), and a woman, Yukiho Karasawa (唐沢雪穂). In essence, they have a mysterious relation and appear to collaborate in numerous criminal events along their life.

Don't be mistaken. This book is hardly a detective fiction. You do not have to guess what happened or who did it, and there is little logical deduction. Nonetheless, the way that the story is told is remarkable - it reminds me of the paintings of Pablo Picasso during the period of analytic cubism. At the first glance, the picture seems fragmented. But, as you turn the pages and the story gradually unfolds, you would appreciate Higashino is trying to get you see a complicated story from multiple angles.

Of course the story is not flawless - but which one is? In this instance, if what Ryoji Kirihara told Noriko Kurihara (栗原典子) about his physical disability was genuine, he could not have helped Tomohiko Sonomura (園村友彦) in that hotel incident.

PS. The first few chapters of the novel also reminded me of The ABC Murder of Agatha Christie. But the difference between Higashino and our queen of detective fiction is obvious - if Byakuyako were written by the latter, I am sure all the murders and assaults were orchestrated by a third party behind the curtain.

How about Kazunari Shinozuka (篠塚一成) ?

Obituary

Professor John Vallance-Owen passed away on 23 July 2011, at the age of 90.

JVO, as people usually called him, was the founding Professor of Medicine of our university. He took up the post in early 1980s after retired from UK. I met him once or twice as a pre-clinical medical student, and, when preparing for my membership examination, had the honor of attending one of his bedside tutorials.

I shall not elaborate on his achievements here. But a small piece of his information I learnt from the man who used to have a moustache is remarkable:

As our department chairman for over 5 years, JVO never held a single department meeting. No, there was no division head meeting, department board, teaching subcommittee, or whatever. It was long before the days of email. Every problem could be solved by talking face-to-face within his office or along the corridor. Things would happen as said, and there was no need of documentation - people simply took the words of the others.

He is, alas, the all time idol for people with a distaste for hypergammaglobulinemia and granuloma.

PS. For those who are not familiar with administrative immunology, please refer to http://ccszeto.blogspot.com/2008/01/lymphocytes.html and http://ccszeto.blogspot.com/2008/01/granuloma.html

Nationalize

I was horrified with Sir Humphrey's idea, "Would that happen to our city as well ?"

"Don't be silly," the senior civil servant chuckled, "Your ex-colonial government is actually going to the opposite direction."

"You think so!? I suppose our freedom of speech is not getting better." I sighed.

"You've misunderstood me. Yes, the Corporation could very well work for the Big Brother. That may happened in a country which tries to know who are speaking against the government after earthquake or train crash - just imagine the Komitet Gosudarstvennoy Bezopasnosti (KGB) is run by a private company."

"True. But couldn't that also apply to our government?" I asked.

"Alas, rather than privatizing national business, your Donald - or the Legislative Council as a whole - is doing the opposite and actually trying very hard to nationalize private organizations," the retired cabinet secretary suddenly became serious, "Don't you know your government is now doing charity work - which is, by the nature of the thing, a task that should be run by the private."

"Oh, do you mean the Community Care Fund (關愛基金) ?"

Privatize

I found myself fortunate and was not eating while Sir Humphrey was making that last remark, or I would have died of suffocation.

"You know, although Mr. Murdoch seems to be in hot water at this moment, I consider that as a kind of road show and he probably did impressed some potential customers," the senior government official continued.

"I think the sales of all his newspapers dropped after the scandal was out?"

"Oh, I mean bigger business than that."

"Such as...?"

"Such as offering their service to governments that treat some people more equal than the others, or countries whose economic and technical advances are running far ahead of their humanistic quality."

I was silent, pondering to digest his meaning. All of a sudden, George Orwell's Nineteen Eighty-four came across my mind, and I exclaimed, "You mean, the Big Brother could delegate his work - or get privatized !?"

"Privatization. That's exactly the word." Sir Humphrey smiled, "Wasn't that the reason why the old man supported Margaret Thatcher right from the beginning ?"