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Tribunal Decision Suggests You Need A Maths Degree To Decide If You Can Get PIP

January 7, 2016

With many thanks to Benefits And Work.


A recent personal independence payment (PIP) decision by an upper tribunal says that probability theory must be used to calculate eligibility for claimants who have more than one health condition. The decision even goes into great lengths about how to mathematically calculate the probability of two independent conditions occurring for more than 50% of the time.

Bad days
The bizarre decision relates to a claimant who had both chronic obstructive pulmonary disease (“COPD”) and rheumatoid arthritis.

The first tier tribunal found that the claimant had 3 bad days a week for COPD, and 2 to 3 bad days a week, depending on the weather, for rheumatoid arthritis. Each condition affected the claimant’s ability to carry out some of the activities in the PIP test, such as preparing food or dressing.

The tribunal decided that the claimant’s conditions did not cause him to satisfy any point scoring descriptors for over 50% of the time, as required by regulation 7, so he was not eligible for PIP.

Probability theory
The upper tribunal judge, however, held that the tribunal had failed to find out if the effect of one condition was enough to cause problems or whether there was only an issue when both conditions applied at the same time.

If the effects of either condition on its own was enough to allow points to be scored, it would still be necessary to work out how many days a week on average, the claimant was affected by one or both conditions. If 50% or less then no award of PIP could be made.

Relying on a submission by the DWP, the tribunal judge went on to set out in great detail how to calculate the probability of the two conditions occurring for more than 50% of the time.

We have reproduced, some, though by no means all, of the mathematical evidence below.

If we say that the rheumatoid arthritis occurs 3 times a week then the probability that regulation 7 is satisfied is worked out as follows:

Probability(A or B) = Probability(A) + Probability(B) – Probability(A and B)

The probability of event A (arthritis) occurring, 3/7, is added to the probability of event B (COPD) occurring. 3/7 + 3/7 =6/7.

However, this probability (6/7) also includes the times on which the COPD and arthritis both occur. This must be subtracted. It is double counting.

The probability of the COPD and arthritis both occurring is 3/7 x 3/7 = 9/49.

We need to subtract 9/49 from 6/7. To do this we convert 6/7 into 42/49 (by multiplying by 7). We can then do the simple sum 42/49 – 9/49 = 33/49. This is the probability of an operative condition being present on a given day.

33/49 can otherwise be understood as 4.71/7, if you were looking at this on a weekly basis (as we have been here).

Therefore the descriptor is satisfied for more than 50% of the days.

5 Comments leave one →
  1. January 7, 2016 1:53 pm

    Reblogged this on disabledsingleparent.

  2. January 7, 2016 1:53 pm

    Tweeted @melissacade68

  3. January 7, 2016 1:55 pm

    Reblogged this on Poppy's Place and commented:
    Very interesting blog here…..

  4. Andreew Longworth-Dames permalink
    January 7, 2016 5:28 pm

    Never heard such nonsense. As if two physical disabilities can conform to such mathematical niceties week in week out.. I am reminded of pinheads and angels! The message is don’t say if your condition is that variable. Anyway they sound like two conditions that don’t just turn off and on anyway. I suffer from a genetic form of athritis and made it quite clear that it is not variable. What I do find is that the pain emphasis is variable. Different joints can be more painful at any given time. My advice is to make sure you don’t give them the chance to belittle your condition. Always give the worst case scenario when describing your condition and stick to it.

  5. September 25, 2016 5:19 pm

    You seem to have missed the point – the disabled person WON this appeal!
    If you check the judgement you’ll see that formula was provided by the disabled person’s representative.
    What the judgement support the point that the disabled person was affected by two different and unrelated conditions. Each affected him less than 50% of the time. The first tier tribunal incorrectly refused the appeal on the basis that more than 50% of the time the disabled person’s ‘activities of daily living’ would not be affected.
    It is obviously true that disability varies and cannot be pinned down exactly to mathematical formulae – but the legislation has been written so that a judgment has to be made as to whether a person is affected more than 50% of the time (to be fair how else would if be drafted?; some cut-off is necessary) .
    Application has to be pragmatic and this appeal was successful for just the reason Andreew Longworth-Dames (sic) makes: the two conditions act independently and unpredictably so, hence rather than simply dismiss the need because both conditions occur less than 50% of the time (as the disabled person told the first tribunal) the appeal tribunal accepted the argument that at any point one of the two unrelated conditions was likely to be affecting the disabled person.
    A degree in mathematics is not needed, the court was simply illustrating the logic.

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