Nigel 
May 19th,2010
the old-fashioned type
So there I was cleaning my teeth with the trusty old electric brush when quite naturally my thoughts fell to sleeping tablets.
Sometimes I collect Jenny’s prescription from the Doctors’surgery and fetch the medication. Last time the duty pharmacist,trying to be helpful,warned me about the number of sleeping pills included.
“She’s being given rather a lot. You need to be aware that clinical trials show this medication ceases to have any effect if you take it for more than three weeks.”(I think he said three weeks –thereabouts anyway).
“That’s okay,”I said,“that’s just clinical research. She gets them on repeat prescription and they work for her.”
He looked at me oddly. You’re not supposed to question the findings of clinical research,just take the raw findings as fact. “She may think they’re helping but they’re not. She really should stop taking them.”he said.
I smiled,hopefully in a warm rather than condescending way. “Actually research is limited in various ways. The tablets definitely help her sleep because if she doesn’t have any she doesn’t sleep at all.”
He seemed an intelligent guy and was clearly educated in some senses of the word,yet looked at me first blankly and then with mild annoyance. He,after all,was the qualified pharmacist.
The trouble is that research into the effects of medication is bound to be limited. Usually the number of people in the test sample is small. Also the people devising the test are handicapped by the limits of their own experience and imagination. I could ramble on about research into use of sleeping tablets but that’s a rather obscure area.
So let’s think about whether electric toothbrushes are more effective than non electric. Now all of us I hope use a toothbrush of some sort.
The electric ones were marketed in part as being more efficient than hand brushing. This claim has been tested,up to a point. The conclusion I’ve encountered several times is that they are not more effective. Common sense,and natural laziness,baulks at this outcome. As I brushed my teeth I’d been thinking up possible reasons why the research might have been flawed. And this applies to research into the use of sleeping tablets as well as (for a later post) whether or not tranquillisers are addictive.
So you take a random group of people and split them into three groups. One group must use electric brushes for the next,what,six months. One must brush by hand. The third carry on as normal. At the beginning and end of the period experts check everyone’s teeth. Surprise:no significant difference between the first two groups. In fact in one study the electric group showed more deterioration.
What happened?
As I brushed my own teeth I got to thinking about what I was physically doing,and what my attitudes to cleaning my teeth have been at various ages.
The brush has a timer. If you spend long enough on each tooth then shortly before you finish the motor stutters. If you don’t spend long enough then the brushing is far less effective.
Add this to one of the great advantages of the electric brush –it does most of the work and half the thinking for you. With a hand brush you not only must consider which part of your teeth to brush first,but also how you brush them. Brushing horizontally will miss a lot of enamel,so you need to use some sort of up and down motion. I was taught to start with edge of bristles on gum and roll so they sweep the whole length of the teeth,then repeat a couple of times before moving on –spend at least a second on each side of each tooth.
Now imagine a normal person being given an electric brush by the researchers. This requires a completely different technique. Were they taught how to use the brush effectively? I don’t know. I wasn’t. I just bought it and away we went till the first time the motor stuttered and I thought it must have broken. Then I read the instructions.
So people in the first group may not have been using their brushes correctly,but there’s a more compelling problem. We’re lazy. Given a dish washer,who hand washes the dishes? Given a car,who walks? You can feel how much faster the electric toothbrush is working. The busy buzzing tells you it’s more efficient. You can get carried away and just move it slowly across the line of teeth,but it also needs to move up and down in order to clean each tooth from gum to tip. It is so easy to halve the time with electric and actually leave your teeth inadequately cleaned.
And this had to be a long term project. The researchers were not observing their test subjects every time they brushed –simply not practical. How many of the electric people lapsed into lazy habits? We’ll never know. But it could dramatically affect the conclusions.
The only valid way to draw conclusions from scientific research is to read the full report,not just a summary. This is not easy,but unless you know exactly how the research was designed,how the data was processed,and what the exact statistical values were,you’re too likely to draw false conclusions. We trust experts to do this for us,but what if the ‘expert’is a journalist in a hurry,or a scientist who doesn’t really understand the limitations of research?
Mr Leech in the library with the sleeping tablets,obviously
sleeping tablets in fiction lol
In fiction,especially murder mysteries,sleeping tablets receive their own dose of poetic licence. How many times has the villain mixed powdered sleeping pill into someone’s bedtime drinking chocolate and the target has not only dozed off as quickly as if hit over the head with a railway sleeper but also stayed dead to the world for eight hours while noisy events happened round them? The pills don’t work like that.
A general anaesthetic does because it is more powerful and is injected straight into the main blood stream so it reaches the brain in seconds. Sleeping pills first have to be absorbed by the stomach lining. This is a slow process. There is a significant time lag while the concentration in the blood stream rises,and the person who took the tablets gradually feels more sleepy. Effectiveness of the medication is also influenced by whether or not you’ve used it recently,and what frame of mind you’re in –which can be affected by mental illness. Taking a dose does not force you to sleep. With luck it should make it easier to sleep.
Never mind,there are so many other factual inaccuracies in murder mysteries but we still enjoy them. Which real police force would allocate just an Inspector and his trusty Sergeant to investigating a murder? But we love the Morse books and films. Mind you I don’t think Colin Dexter ever has his characters supping a nightcap of drinking chocolate.
