Six million people can be wrong

There are a lot of statistics bouncing around about extended hours. One that keeps coming up is the demand of six million patients for them. Here we have no less a figure than the Secretary of State for Health answering a question in parliament.

About 6 million people in our patients survey said that they want improved access to their GP in the evenings and on Saturdays, which is why we are seeking to reach a negotiated settlement with the BMA.

The survey he seems to be talking about here is the 2007 GP patient survey. Looking at the results things are not quite as clear as they might seem from the above answer. For a start six million people did not say anything of the sort. There were not even six million in the survey. The survey was only sent to 4.7 million people and less than half of them (2.3 million) sent it back. The people sent surveys were picked largely from those that had been to their GP in the previous six months.

So where does this figure of six million come from? Well out of those who replied 16% said that they were, in some way, dissatisfied with opening hours. Take that figure together with the population of England over 18 (just shy of 40 million) - multiply and you get a figure of around around about six million. Clearly what Mr Johnson intended to say was that if the whole adult population had been asked and they all replied he believed that six million people would say that.

Now that is a pretty rotten bit of statistical conjecture. It assumes that all of those people who did not reply would think the same way as those who did. Of course it may be they did not reply because they had not particular views. Even more ambitiously it assumes that that group that were not polled - people who had not seen their GP recently - had identical views.

Worse still it ignores the fact that only ten per cent were able to say in what way they were unhappy with the opening hours (lunchtimes, evenings etc). Only 208,000 asked for increases outside of the usual 8-6.30 Monday to Friday - about 9% of the total responses. It is difficult to call this a massive pressure. Even with the simplistic extrapolation this would only be 3.6 million. The pie chart graphically shows the responses (click on it to enlarge).

Its not just me saying this. When you pay 11 million pounds for a survey MORI gives you some quite detailed analysis - in this case 111 pages (2.4Mb) of it. So what do the experts have to say?

When interpreting the findings, it is important to remember that the results are based on a sample of patients registered with a GP in England who responded to the survey, and not the entire population of England.

The vast majority of patients (84%) say they are satisfied with the hours their GP practice was open during the last six months, while the remaining 16% say they are dissatisfied with the opening hours.

What do we know for sure then? Simply there is some demand for extended hours, but not a lot. You can read the MORI report for some detailed socioeconomic breakdown of the figures. What is quite clear though is the figure of six million people is definitely wrong.