Another Spectrum

Personal ramblings and rants of a somewhat twisted mind


On flu shots and statistical nonsense

This morning I took a pleasant twenty minute walk to my doctor’s surgery for a flu shot. This was the first time I have had a jab for the flu. It’s not that I’m afraid of injections, it’s just that I’ve never felt the need to be vaccinated against the flu.

Firstly, I’m one of those fortunate people who seldom catch the flu. If I do, It’s no more than a very minor nuisance.

Secondly flu shots aren’t cheap. My bank account would likely be lighter by around $50. That’s not an inconsiderable amount when my only regular income is my superannuation.

So why did I have one today?

It was free. As I recently turned 65, the health system in its wisdom has decided that I am eligible for a free flu vaccination. Do I really need it? possibly not. If the doctor’s surgery hadn’t phoned me, I would not have bothered But if it’s free, it’s worth considering. Besides, I’m not getting any younger, so I guess that the odds of becoming seriously ill with the flu is increasing.

While I was waiting the mandatory ten minutes after the shot before being allowed to leave, I picked up the morning newspaper. An article on the front page was titled “Dumb ways to . . . end up in hospital”. The statistics looked dubious immediately as one of the first “facts” they presented was that there were “nearly 200,000 hospital discharges in 2012”. That seemed to be an extraordinary low number for a population of 4.5 million people.

The article then went on to say that you were more likely to end up in hospital being injured by a powered lawn mower than being injured by a gun. Over 200 were injured by power mowers which means than more than 1 in a thousand admissions to hospital were caused by lawn mower injuries. That seemed an impossibly high rate. Perhaps I should stop mowing my lawn.

Following a few other statistics about the number of discharges following dog bites compared to bee and wasp stings, and similar inconsequential injuries, the article mentioned that almost 70,000 patients were discharged after suffering injuries arising from their medical or surgical care. What!? One in three people were injured while in hospital?

I’ve been in hospital more than 10 times over that last few years, so either I’ve been incredibly lucky, or there’s something I don’t know about but should. Then I remembered that lies and statistics often go hand in hand, and resolved to clarify the fact when I returned home.

Although I couldn’t find the statistics for the year quoted in the newspaper, I did manage to locate the statistics for the preceding year. And they paint a quite different picture.

The “nearly 200,000” referred not to total discharges, but to hospital discharges involving unintentional and intentional injury.The total number of discharges was a little over one million. This puts the rest of the statistics in a more reasonable light. The “statistic” on in hospital injuries included complications after surgery, abnormal reactions to medication, no matter how minor and several other cstegories. Actual “medical misadventures” totalled less than 500, or less than 0.05%. I can breathe a sigh of relief.

The statistic of one in a thousand discharges following lawn mower accidents drops to one in a thousand injuries requiring hospitalisation. Perhaps I’ll have to find another excuse to avoid mowing the lawn. 189 people were discharged following “contact with a powered lawnmower”, while 73 were discharged following firearms injuries. The statistics don’t mention the number of deaths, and as admissions nationwide don’t seem to be kept, I’m not able to ascertain the relative danger mowers and guns, but I think I can sleep safely knowing that mowers are more of a threat to life and limb than a gun.

One interesting fact that struck me was the difference in the rate of discharges between males and females. The total rates are quite similar, but of the more than 700 types of injuries listed I am hard pressed to find any where male injuries are less frequent than female injuries. For almost all types, males are two or three times more likely to be hospitalised than females. In the case of guns, 71 of the 73 cases were male, while for lawn mowers, 143 of the 189 cases were male. So far the only injuries I have found where females clearly outnumber males is falls on stairs (2341 vs 1431) and unspecified falls (3389 vs 2196). The disparity of injuries between the sexes is worthy of a post in itself.

I’ve always had a healthy dose of cynicism when reading/watching news, and the article in question does nothing but to reinforce that cynicism. It’s a shame that so many people are easily taken in by “facts” without doing a little research of their own.