Wednesday, October 31, 2007

The Minority View

Someone said that "the 2000 bar lawyers who went to the Walk for Justice are a minority", and that "there's no erosion of the judiciary system in our country".

Someone has just slapped himself.

If 2000 lawyers are the minority voice, what about his own voice then? If 2000 concerned people should not raise one's eyebrow; by the same token, why should anyone listen to the voice of one guy who claims that there's no problem?

My brain implodes with the logic.

3 comments:

Monday, October 29, 2007

Zero Gravity (2)

This post is a continuation of an earlier post.

Space isn't remote at all. It's only an hour's drive away if your car could go straight upwards.

Fred Hoyle
So somehow, people always use the term "zero gravity" to describe space as though it somehow escaped Earth's gravitational pull and is effectively receiving no attraction from the gigantic rock at all. You see terms like "there's no gravity in space" all over the place, spoken even by the astronauts themselves.

For example, let's look at a snippet from a supposedly educational article in The Star:
Half of all astronauts suffer space motion sickness when they encounter microgravity and feel as if they are falling. This affects our neurovestibular system, which is what helps our body keep proper orientation while on Earth. This feeling is not dissimilar to the sensation felt after you have been on a terrifying roller-coaster ride. It simply means that your body doesn’t know which way is up, down, left or right.
This paragraph is misleading.

When the astronauts encounter microgravity (a term used erroneously in the context of "zero gravity"), they don't only feel "as if they are falling" - they ARE actually falling. The astronauts feel weightless because the International Space Station is in an orbit around the Earth, and an orbit is a free-fall. And you feel weightless when you are free-falling.

I am not a textbook author, so I might not be good at explaining it. But here is a great explanation I found through a fabulous web page (which by the way, clarifies a lot of scientific misconceptions I blogged about some time in the past):
Everyone knows that the gravity in outer space is zero. Everyone is wrong.

Gravity in space is not zero, it can actually be fairly strong. Suppose you climbed to the top of a ladder that's about 300 miles tall. You would be up in the vacuum of space, but you would not be weightless at all. You'd only weigh about fifteen percent less than you do on the ground. While 300 miles out in space, a 115lb person would weigh about 100lb. Yet a spacecraft can orbit 'weightlessly' at the height of your ladder! While you're up there, you might see the Space Shuttle zip right by you. The people inside it would seem as weightless as always. Yet on your tall ladder, you'd feel nearly normal weight. What's going on?

The reason that the shuttle astronauts act weightless is that they're inside a container which is FALLING! If the shuttle were to sit unmoving on top of your ladder (it's a strong ladder,) the shuttle would no longer be falling, and its occupants would feel nearly normal weight. And if you were to leap from your ladder, you would feel just as weightless as an astronaut (at least you'd feel weightless until you hit the ground!)

So, if the orbiting shuttle is really falling, why doesn't it hit the earth? It's because the shuttle is not only falling down, it is moving very fast sideways as it falls, so it falls in a curve. It moves so fast that the curved path of its fall is the same as the curve of the earth, so the Shuttle falls and falls and never comes down. Gravity strongly affects the astronauts in a spacecraft: the Earth is strongly pulling on them so they fall towards it. But they are moving sideways so fast that they continually miss the Earth. This process is called "orbiting," and the proper word for the seeming lack of gravity is called "Free Fall." You shouldn't say that astronauts are "weightless," because if you do, then anyone and anything that is falling would also be "weightless." When you jump out of an airplane, do you become weightless? And if you drop a book, does gravity stop affecting it; should you say it becomes weightless? If so, then why does it fall? If "weight" is the force which pulls objects towards the Earth, then this force is still there even when objects fall.

So, to experience GENUINE free fall just like the astronauts, simply jump into the air! Better yet, jump off a diving board at the pool, or bounce on a trampoline, or go skydiving. Bungee-jumpers know what the astronauts experience.
So there we have it: Astronauts are not floating in zero gravity, they are constantly falling under the gravitational force. They feel just like a bungee jumper, a skydiver, or a person in a roller coaster going down a gigantic drop.

The concept of "zero-gravity" and freefall should be explained with the diagram on the right.

Say you are on top of a high mountain, and you throw an unfortunate guy forward with great force. If you throw him just lightly, he might land on, say, point D. If you throw him with even more velocity, he might end up landing on point E, F, or even B. But throw the poor boy with a sufficient velocity, and he will never land, as he will just keep on curving around the earth and missing the ground constantly. That is exactly what happens to a satellite in an orbit. An orbit is just a kind of freefall, on a special type of projectile motion which takes a form of an ellipse or a sphere.

[Read more about this diagram and its explanation in this Wikipedia article - Newton's Cannonball]

It might be just my personal peeve, but I have always been appalled by how little clarification is given about the term "zero gravity" in the media. When I was young, I had always thought that there is zero gravity pull in the space, and it was until quite late that I realized all the astronauts were just free-falling. And more people should learn about this misconception if we really want to educate our people about the space.

4 comments:

Saturday, October 27, 2007

Rock, Paper, Scissors

5 comments:

Friday, October 26, 2007

Zero Gravity (1)

Warning: The following is going to be a nerdy rumbling. If you have no interest in physics, space, gravity or whatsoever, you should avoid this article so that you don't fall asleep and wake up blaming me for it. :)

I have a peeve about the term "zero gravity".

In the flurry of space tourism news in recent weeks, the term "zero gravity", or "microgravity" cropped out like m-u-s-h-r-o-o-m-s after a monsoon season. And I am disturbed by the fact that the misleading terms have been taken used so rampantly without further explanation in the media.

To begin with, let's look at a few examples from the news articles:

Living in space is quite different than on Earth. That difference, of course, lies in that trifling matter we call gravity or, rather, the lack of it.
As it left the earth's atmosphere, the rocket achieved zero gravity within the next four minutes and soared into the stratosphere.

When the rocket motors start to roar, our angkasawan will begin to experience an increasing G-force in proportion to the increase in acceleration.

[snip]

This period of high-acceleration will last for 8 to 9 minutes until the rocket ship travels 100km above the Earth and reaches the necessary speed of 18,000mph, sufficient to carry it all the way to the International Space Station (ISS). This will take about 50 minutes after the engines stop firing and during this time, zero-G will prevail and this is when astronauts will experience that sense of weightlessness most people associate with being in space...

[snip]

The good news is that once you arrive onboard the ISS, zero-G is nullified as there will be a “synthetic gravity” produced by spinning the space station around its centre. This is a very necessary factor for the well-being of the astronauts as microgravity exposure alters the human body in many ways.

Half of all astronauts suffer space motion sickness when they encounter microgravity and feel as if they are falling. This affects our neurovestibular system, which is what helps our body keep proper orientation while on Earth. This feeling is not dissimilar to the sensation felt after you have been on a terrifying roller-coaster ride. It simply means that your body doesn’t know which way is up, down, left or right.

All the news articles sound very convincing. After all, as a child, haven't we all seen how astronauts float effortlessly in the outer space when there are no gravity forces, and didn't everyone enthusiastically make "angkasawan" our childhood ambition because of the sheer fun of floating? Everyone knows there is no gravity in the outer space, outside the Earth's atmosphere!

So, what's wrong with me and my peeve with "zero gravity", you may ask.

The problem begins with the word "gravity". Gravity, as first expounded mathematically by Isaac Newton, is a mutual force that exists between any two objects with a mass. This force is directly proportional to the mass of both objects, but inversely proportional to the square of the distance between the two objects. The fact that there is a gravitational force pulling us towards the ground all the time, is due to the force between the gigantic rock ball and all the various molecules that make up our body.

Mathematically, the relationship is as stated on the right.

  • F is the gravity force
  • G is a constant (6.67300 × 10^-11)
  • The two m's are the two masses
  • r is the distance.
So say, what is the gravity force acting on myself right now? The earth's mass is 5.9742 × 10^24kg, my mass is 70kg, the distance between myself and the centre of Earth is 6 378.1km. So, if you do the calculation (check out the link!), it turns out that there is a gravity force of about 686 newtons between myself and the Earth.

So, what happens if I go on a sightseeing trip in ISS?

The International Space Station is an artificial satellite which flies about 319.6 km to 346.9 km above the Earth's surface. Okay, let us redo the calculation of the gravity force in action when I am up there... Surprise, surprise, the answer is 620 newton! The gravity force is only about 10% less than what it is for me right now!

Isn't all that confusing? There is supposed to be zero gravity in the ISS! That's what the newspaper and the astronauts told us! Aren't they floating in space?

What's wrong in here?


[To be continued...]
[Continued in this post]

4 comments:

Tuesday, October 23, 2007

Latest Grey's Anatomy Photos

Featuring Tun Dr. Mahathir and his surgical team in IJN!


Source: A deleted post in Marina Mahathir's blog.

Note: I am not showing the photos here as she expressly forbade any form of reproduction of the three photos in any media. All the links here are from her blog and all rights are copyright of Tara Sosrowardoyo.

0 comments:

Donate to Wikipedia!

Wikipedia has just started its annual fundraising campaign, and I just donated a little bit to help the cause.

If you use Wikipedia and find it useful, help it grow and flourish by supporting it financially. Wikimedia (the organization behind Wikipedia) is a non-profit charitable organisation, and its operation is fully dependent on donation. If I could only donate my money to one cause online, I would choose Wikipedia. Look at what the donors have to say about Wikipedia here.

Donate to support one of the greatest websites in the world!

5 comments:

Monday, October 22, 2007

Of Forwarded Hoaxes And Spams

A few minutes ago I received one of those emails.

That email claimed that for every person I forward itself to, I will be paid 245 dollars by Bill Gates; and if that person forwards it on, every secondary forward will give me 243 dollars, every tertiary forward will give me 241 dollars, and so on and so forth. In the previous forwarded content, there are apparently some people saying very convincing things like:

OH my god, it worksss!!!! I just checked my bank account and it now has 9500 dollars in it!
Another person said
I got 4000 ringgit from Bill / Melinda Gates Foundation! Amazing!!
Seriously.

Bill Gates and his foundation may be some of the most generous philanthropist around, but they donate to AIDS and Malaria researches, not to spoilt kids like you and I.

Some people forward emails like this and some other types of urban legends, because, they say, there's no harm trying / spreading it. But it's wrong. There are great harms.

By forwarding such chain hoaxes, you literally give away your email addresses, and spammers can easily collect a large collection of email addresses when they receive a copy of such emails. If you forward such emails, don't complain when you receive thirty Viagra and penis enlargement advertisements everyday - you gave out your email address merrily in the first place.

If you are concerned, here are some tips you could try to avoid spammers from collecting your email addresses in the future.
  • Don't write your email addresses in public web pages e.g. forum, blog, blog comments etc. Spammers run automated programs which trawl every single email address they could find in all web pages, so posting your email is like leaving your key in front of your house door.
  • If you have to leave email addresses in a web page, try to think of ways to rewrite it. E.g. abc [at] gmail [dot] com / doremi under yahoo / santaclaus--hotmail.
  • If you have friends who forward emails to you regularly, ask them to put your email address in the BCC column. That way your email address would not be shown to the others.
  • Don't forward emails. If you want to share something, post them on your blogs, Friendster bulletins, Facebook notes etc; but don't forward them if you could help.
  • If you receive unsolicited emails which offer an option to "unsubscribe" from the list, don't be tempted to do so. Depending on the sender, very often the "unsubscribe" link is just a lure to actually confirm that your email address is valid. And if you "unsubscribe", you might actually get more spams in the future because they now know that your email address is a good one.
  • Use Gmail. It doesn't exactly help you avoid spammers from collecting your address, but its spam filter is so effective that I haven't seen any spam for weeks.
  • If some spams slip into your inbox, use the "mark as spam" option instead of deleting it. It helps the email service provider identify spam better for everyone.
  • Unfortunately, if you already receive tons of spams everyday, there's not much you could do apart from setting up a new account, preferably from Gmail.
Try your best to protect your email addresses. In this age, your email address is as important as your mobile number, postal address, or your age - you don't want to give it to strangers and thieves.

3 comments:

Thursday, October 18, 2007

A Special Patient (2) - About My Research

This post is a continuation of an earlier post.

This is a conversation between myself and a patient, and it kind of explains the research I am doing since I am giving explanation to the patient in layman term below.

Me: My name is Yang, and I am a student doctor in Anaesthetics department. How are you today?

Maria: Good! But hungry, really hungry.

Me: Hah I am sorry about that... they like to starve the patients, don't they? :) So... you are having a surgery on your back today, and after the surgery you are going to stay in the hospital for a few days.

Maria: Emm hmm...

Me: We are a bit concerned about the pain killer's effects on the patient after the operation. For your operation, you will receive a routine pain killer after the operation. Those are really good drugs, but from our experience, it sometimes cause a bit of obstruction in breathing, especially when you are sleeping. Do you have a bit of snoring when you sleep, by the way?

Maria: Yeah sometimes, especially when I am tired.

Me: Yeah snoring is a kind of partial obstruction too. Those obstruction aren't exactly dangerous, as you would gasp for more air naturally when you don't get enough of it. But after an operation, the obstruction is not good for the recovery because you don't get enough oxygen when things get obstructed. So now, we are having this investigation, or research, to investigate the effect of pain killer on breathing. We kind of identify patients who we think are at a higher risk of obstruction, and since you have a high weight and you do snore, we think that it's good for you to be part of the study.

What we are doing is, if you agree, after the operation, we will put a couple of bands which will go around your chest and the abdomen, a tube which goes below your nose, and a few wires. (see picture) What they will do is to record your breathing at night, and on the second morning, I will take them off at about 8 o'clock, then use the computer to analyse the result. If we do find serious obstruction, we will refer you to a doctor.

And oh yeah, for this study, you will be given one of two types of pain killers after the operation, one is morphine, another is a drug called tramadol. You will be given a button to press which will give you a dose of pain killer when you need it.

So, yeah, that's basically what the research is about. So would you mind to participate in it?
[To be continued...]
[26 Nov: Continued here]

3 comments:

Wednesday, October 17, 2007

Who Do You Blog For?

This post is adapted from my comment in this post.

For some reasons, people like hypothetical and dichotomous questions. In other words, we always enjoy discussing and debating questions such as "Given options A and B, what would you choose?".

There is a golden example which I am sure everyone is familiar with. I believe that at some stage, someone in a romantic relationship is bound to ask his / her partner:

Given your family (or relationship) and your career, what would you choose?
Another similar question is,
Between myself and your mum, who would you choose?
I am not sure about others, but I have always disliked this kind of this-or-that questions. Those questions simplify life into two black-and-white options, and while they are good for setting people to think about goals and priorities, there's never going to be a good answer to them. It's not as if there's a two-way on-off switch that must turns on one option and turns off the other. Different scenarios call for different decisions, and in each case, the two options are never mutually exclusive.

But still, some people enjoy a simplistic approach to this issue, and judge others (even their own partner) based on their answer to those questions. I find that a bit disheartening.

On an unrelated note, when it comes to blogging, there is a popular dichotomous question:
"Do you blog for yourself or your readers?"
There are some pretty polarised views regarding this issue. While some people pretty much take their blog as a personal sanctuary and care not about the readers; some people spend lots of effort crafting posts which cater to the readers' need, sometimes at the expense of their personal interests.

My personal answer to this question is, "it depends…" To put it shortly, I would say it depends on what you write the blog for, and how you derive gratification when you blog. :)

For some people blogging is simply a kind of emotional catharsis or a personal habit, and for them the readers’ number and responses are not in the back of their mind - in that they can simply "blog for themselves".

For some other people, while essentially their blogs remain as personal chronicles, a big part of satisfaction comes from the readership, the interaction between reader and themselves, the satisfaction of readers etc. In that case “writing for the readers” would indeed be of high priority.

So, should the readers be made the first priority in blogging? It's pretty much an individual choice, and is dependent on the aforementioned factors. For example, if you ask Kennysia to throw away the reader-orientated posts and write all for himself, he’s going to lose quite a lot of readers. But say if someone relies on blogs to vent his frustrations but is forced to avoid writing it because some people tell him “I don’t like to read your angry stories”, then it would beat his purpose of blogging altogether.

So I guess the self vs. readers issue of blogging is more of a shade-of-grey kind of thing… Everyone has their own balance, and with a healthy give-and-take between those two considerations, both the blogger and the readers should enjoy the blog at an optimum level.

At the end of the day, a blog is all about a blogger and his readers. After all, a written chronicle without the readers is just a diary (or a private blog, for that matter), not a blog.


Note to Wei Liang: This post is not directed to you, and when I say I dislike dichotomous questions, it's not a reference to your question. It's just my feeling in general to this type of questions. :)

Image Credit: A Conversation, by JeanFrancois

8 comments:

Tuesday, October 16, 2007

Clockwise? Anti-Clockwise?

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What can you see? Clockwise rotation? Anti-clockwise rotation? Both?

This is an interesting test posted on the Daily Telegraph website, and it is purported to test whether you are a left-brained or right-brained person. But from my one semester of neuroscience, I would say that the left-brain / right-brain dichotomy thing is mostly bullshit. While there are indeed dominant spheres for language processing (most people are left-sided, some people are right-sided, even less are both-sided) as well as spatial perception (which is usually on the right side); the left-side = rational, right-side = emotional / linguistic / artistic theory is a hypothesis and has not been substantiated scientifically. It is often exaggerated in popular psychology and often is used to sell "boost your left brain" or "train to use both your brains" kind of pseudoscience stuff.

After some searching around, I discovered a few web pages which discusses this image and the left-brain-vs-right-brain issue in more detail:Interesting, huh?

Source: The Right Brain vs Left Brain via Facebook

12 comments:

Monday, October 15, 2007

How Does It Feel Like to Die?

Death comes in many guises, but one way or another it is usually a lack of oxygen to the brain that delivers the coup de grâce. Whether as a result of a heart attack, drowning or suffocation, for example, people ultimately die because their neurons are deprived of oxygen, leading to cessation of electrical activity in the brain - the modern definition of biological death.

If the flow of freshly oxygenated blood to the brain is stopped, through whatever mechanism, people tend to have about 10 seconds before losing consciousness. They may take many more minutes to die, though, with the exact mode of death affecting the subtleties of the final experience. If you can take the grisly details, read on for a brief guide to the many and varied ways death can suddenly strike.

Read more here.

6 comments:

Thursday, October 11, 2007

A Special Patient (1)

I had a special patient today. Let's call her Maria.

Maria is a 21-year-old lady who's coming in Royal Melbourne Hospital for an operation called "Lumbar Discectomy". Basically, it means that she's fixing a disc which had slipped out of its usual position between two bones which are located at her lower back. The displaced disc (see figure - the blue thing labelled L5) impinged on her nerves, and has produced pain on both legs, and it's especially worse in the right leg where it expands throughout the whole length. The pain of this nature is usually referred to as sciatica, as it's usually associated with problem with the sciatic nerve (the fat nerve going down the leg in the figure).

Guess what: Maria has had this problem since she was 12.

Maria's predicament remained undiagnosed because it's rare for young people to get sciatica, which is quite common among older population. Throughout the years, doctors had been telling her that the pain was due to muscular problems, and that it would become better with time. It was not until last year when she couldn't bear with the pain anymore, that she asked for another check-up and discovered this problem. Turned out that she had a really severe case of disc prolapse, and if it's not fixed urgently it would progress to a medical emergency called cauda equina syndrome.

So I had a look at Maria because she was suitable for my study. From her history, I discovered a couple of interesting things:

  • She had been smoking cigarette since 12 year old.
  • She smokes marijuana (weed, 大麻) everyday
If you tell one of the more conservative parents only these information, my bet is that they are going to flinch right there and then while the image of a samseng girl is conjured in their mind. To be honest, I had a bit of hesitation too - is she going to be that kind of violent, uncivilized people?

I mustered my courage to approach her for my study. I stood there and called her name out loud in the waiting lounge, and the girl with her mum and her partner stood up and came to me cheerfully.

I thought:

Shit, they thought I am going to call her in for surgery preparation while I am only inviting them to participate in the research. Damn damn damn. They are going to be so mad at me. She's hungry (patients need to fast a long time before their operation) and impatient and all, and now I am going to invite her to be some sort of research participant. I am so dead.

So I showed them to the interview area, my heart pounding real hard as the family remained cheerful.


[To be continued...]
[19/10/07: Continued here]

6 comments:

A Random Tag

I got tagged by Ai Ling. A tag could make quite a good filler post while I have nothing to write in my blog.

So here goes:

5 things in my bag:

  • lots of paper
  • a couple of pens
  • a highlighter
  • a folder
  • can't remember because my bag got locked in the hospital!
5 things in my head:
  • a surprise
  • a friend who's insulted by brainless people
  • how I could improve my cooking (am eating now)
  • what time to sleep tonight
  • a special patient I've met today (will blog about it later)
5 words i frequently use:
  • basically
  • complacent
  • intriguing
  • amazing
  • ironic
(From the words above, it seems like I am always finding fault in people eh?)

5 recent smses received
  • An anaesthetist who helped me in my research
  • Reminder from Google Calendar
  • Ditto
  • Ditto
  • Ditto
5 recent things i just did:
  • Cook dinner for myself and Yong Chin
  • Met Xuan Ni in her house
  • "Set up" my patient for my research project
  • Working on revamping Fotoholics website (I am one of the IT officers)
  • ReComming
5 things in my wardrobe:
  • clothes
  • bed linens
  • socks
  • underwear
  • nothing much
5 things i just ate:
  • "spicy fish" which tasted a bit fishy
  • raisin bread
  • plain bread with water
  • chips
  • cookie with macademia nut and chocolate
5 people i'm tagging:

5 comments:

Tuesday, October 09, 2007

Dumb Dumb Dumb


It's interesting and intriguing how some people spread ignorant hearsays or ask stupid questions on forums or blog posts, when things could have been easily verified or answered by googling or wiki-ing.

Isn't the complacency dangerous?


p/s: Some might contend that wikipedia is not always accurate, but from my personal experience it's usually much accurate than most hearsays.

9 comments:

Sunday, October 07, 2007

Of Red Hands and Sore Feet

There's only one way of receiving hundreds of thank-yous in one morning by clapping your hand mad - be a volunteer at a marathon Event.

There's also only one way of seeing dozens of fuming drivers who complained about blocked roads while not knowing how to reply. Be a volunteer at a marathon event.

Today I was amazed and embarrassed at the same time - I saw so many people who were much older but were running much faster than myself. I estimated there to be around dozens of elderly who were running at a pace of 12 - 16 km/h, while I shuffled last time for 15km at about 8.2 km/h. Paiseh niah.

While it's a good source of inspiration, standing for five hours took its toll on me. I am so exhausted.

3 comments:

Wednesday, October 03, 2007

Making The Right Choice

thinker21Everyday we are confronted with numerous occasions which call for decision-making, and quite often the decisions are related to numbers.

For example, given two options of sugar in a supermarket,

  • A one-kilogram package which costs one dollar,
  • A five-kilogram package which costs four dollars.
Which one would you buy?

Some people reckon that the latter is the better choice, since it is "just eighty cents per kilo". However, some others might say that the former is better because you do not risk the sugar expiring before you finish it, the quality might deteriorate if it's left for too long, "you do not need five kilograms anyway", and so on. Well, there's no clear winning side here, as each pros and cons are weighed differently by different people.

On another occasion, a similar dilemma arose in the issue of tram tickets. As a background, there are a few choices for the prepaid tram tickets, namely two-hourly tickets, daily, and 10 X two-hour. Daily is out of the question because it could be replaced by an equivalent of two two-hourly tickets. So We could buy separate two-hourly tickets (which cost 3.30 dollar each) or buy a ticket with 10 two-hourly values (which costs 27.60 dollar).

Naturally, 10 X two-hourly ticket seems to be the best option. But here comes the real problem - how many of them should we buy? We know very well that there is a price increase every year or two, so if we stock up the tickets we would not need to buy expensive tickets in the future. However, buying lots of tickets turned out not to be the best choice after all - we figured out that at the present rate of bank interest and the predicted price increase every year, we might as well buy the ticket after the price increase, because by that time the bank interest we earn would have covered the price difference. It's quite a bit of tricky maths.

The last case I would like to talk about here is related to medicine. You might think, hey, what does medicine have to do with mathematics? Is it the doctor's bills? Hah let me reassure you that billing is not the main use of maths in medicine. As I mentioned in another post, a lot of medical researches deal with epidemiology and statistics which involve a lot of mathematical application.

Amidst the figures of risks, benefits, odds, ratios and so on, it's very common for people to be misled by default or by design. Take this example:
They [Tom Fahey and colleagues] wrote to 182 board members of district health authorities in England (all of whom would be in some way responsible for making important health service decisions), asking them which of four different rehabilitation programmes for heart attack victims they would prefer to fund:
  • Programme A reduced the rate of deaths by 20%;
  • Programme B produced an absolute reduction in deaths of 3%;
  • Programme C increased patients' survival rate from 84% to 87%;
  • Programme D meant that 31 people needed to enter the programme to avoid one death.
"How to Read a Paper" by Trisha Greenhalgh, 1997
Before you read on, give it a second of thought - which one would you choose? Which one is the most effective, and which one is the least effective?

The book author, Greenhalgh, proceeded to tell us the right answer: all of them are describing the same effect. Many of the health authorities (and I believe many of us as well) didn't notice it:
Of the 140 board members who responded, only three spotted that all four "programmes" in fact related to the same set of results. The other 137 preferred one or other of the programmes, thus revealing (as well as their own ignorance) the need for better basic training in epidemiology for health authority board members.
As a numerical example, let's say when the patients do not enter any program, 84 out of 100 patients survived; while for the rehabilitation program, 87 out of 100 patients survived. Rate of death is reduced from 16% to 13%, and therefore:
  • A) It's a (16-13/16) X 100% ≈ 20% death reduction .
  • B) The absolute death reduction is 16% - 13% = 3%.
  • C) From the figure directly.
  • D) Since the absolute death reduction is 3%, it means that 3 out of 100 patients have benefited through the rehabilitation program. That ratio is equivalent to 1 in 30 patients saved (rounded to the nearest ten, considering the significant digits).
It's amazing just how manipulable our mind is when it comes to numbers. The next time when you see a promotion claiming "buy two free one", remember that it's equivalent to 33% discount. For some reasons, "buy two free one" might seem more attractive to certain people than, say, 40% discount.

Errm.

7 comments:

At the Hospital Entrance

april30_transport_taxi3_webEveryday I enter the hospital early in the morning and leave for home in late afternoon. There's this hospital main entrance which I pass through everyday. Guess what I see every time as I pass through that area?

Smokers.

Or to be precise, a number of patients, some on wheelchairs, some with their drips on, who come out to have a puff.

Also, the ground in front of the hospital is littered with cigarette butts.

Isn't it ironic?


p/s: I have no prejudice against smokers (in particular, their choosing to smoke / not able to pull out from the habit despite knowing the adverse effects). This post is just reflecting on the irony of having smokers crowding a hospital entrance. I am in no way judgmental towards patients based no their smoking habit.

4 comments:

Monday, October 01, 2007

Pathetic Parents

At around 7am this morning, when I was walking to the hospital, I saw this family where the parents pushed their little baby on a pram for what appeared to be a morning walk. They seemed to be such lovely parents, and I told myself that I will emulate them when I become a parent in the future.

The next second, some smoke found its way and wafted into my nose. Naturally, I looked for the source of the nuisance. I literally recoiled when my eyes met the sight - the dad was puffing away on a cigarette, and the mum is enjoying one herself too. They seemed to be pretty engrossed in their conversation, and while they enjoyed their outing, the baby slept calmly, being totally unaware of the health hazards his parents were exposing him to.

How pathetic.

I am not a proponent of draconian legalism, but for a moment I seriously thought that we should punish parents who jeopardize their little kid's health irresponsibly. They don't deserve to be parents.

For a second, I also thought about something: Is it ever appropriate for a person (like myself) to approach the parents and advise them about their irresponsible deed? As a medical student? And if/when I become a doctor in the future, is there a moral obligation, and is it socially appropriate for such an advice?

Regardless, pathetic is the word of the day. Pathetic parents with a pitiful kid.


Image credit: 'Healthy' children with smoking parents aren't really so healthy

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