At Prime Minister’s Questions yesterday the Prime Minister, David Cameron, had a go at the Leader of the Opposition, Ed Miliband. He said:

I am glad that he mentioned waiting times, because, two weeks ago, at that Dispatch Box, he said that waiting times “have risen month on month under this Government”. That is not true. The figures, which he had at the time, show that in-patient waiting times fell from 9.1 to 9 weeks. For out-patients, they went down from 4.8 weeks to 3.5 weeks, the lowest for a year. It is important when we come to this House and make statements that are inaccurate that we correct the record at the first available opportunity.

Forceful stuff. But what do “the figures” actually mean? We’ll come to that in a moment. But first of all, imagine that, in a parallel universe, David Cameron had stood at the dispatch box and said this:

He said long-term unemployment has gone up under this Government, but that is not true. The figures clearly show that the time people remain unemployed is going down. The median time out of work, for all new job-starters, actually fell last month, and now stands at the lowest level for a year. So there.

Okay, now the alarm bells are ringing. The objections are:

1. We aren’t interested in job-starters, we want to know about the unemployed.
2. Most job-starters come straight from another job, so of course the median time between employments is low.
3. The people we really want to hear about are the long-term unemployed. They could be out of work their whole lives and never be picked up by this statistic.

And so it is with NHS waiting times. The figures quoted by David Cameron are the median waiting times experienced by “inpatients” (called “adjusted admitted pathways” in the statistics) and “outpatients” (“non-admitted pathways”). Exactly the same objections apply:

1. We aren’t interested in the patients who get treated, we want to know about patients on the waiting list.
2. Many of the patients being treated have urgent clinical conditions, so of course the median waiting time is low.
3. The people we really want to hear about are the long-waiters. They could be waiting for years and never be picked up by this statistic.

If PMQs were an exercise in revealing deep truths about the government of the nation, and not a political boxing match, then the Prime Minister might have looked more carefully at the figures and said something like this:

I am glad that he mentioned waiting times, because, two weeks ago he said that waiting times “have risen month on month under this Government”. I would like to set the record straight. The figures for February, to which he was referring, show that ten per cent of patients on the waiting list had waited over 19.2 weeks since referral. This was actually a slight improvement on the previous month, so “month on month” is not strictly correct.

However it is true that waiting times have worsened significantly since the record performance achieved just before the election, when ten per cent of the waiting list was above just 16.5 weeks. It is important when we come to this House that we make statements that are meaningful and honest, and I have done so today.

[Hat Tip to joefd for tweeting about analogies]