Innovating without inventing something new

9562611683_cd9584baca_zI’m a pathologist, which means that I run the lab, and I’m continually shocked by all the unnecessary lab work that comes my way. Doctors have to find something wrong with you, because preventative measures aren’t sexy. They know that you’re more likely to appreciate them if they tell you something’s wrong, than if they tell you to stop drinking 40 oz sodas. Humans of New York

This week a report was released that documents changes in Australian GPs’ ordering of X-rays and scans in the decade 2002- 2012. The report includes an evaluation of the quality of GP test ordering against available guidelines. The team compared two periods: Apr 2002- March 2005 inclusive (Period 1) and April 2009 to March 2012 inclusive (Period 2). Three factors were found to be relevant:

  • The number of encounters between doctors and patients
  • The number of problems managed at encounters
  • The rate of ordering tests in the management of problems encountered

It was not surprising that people are attending doctors more often and that they are presenting more problems than before. However the rate of imaging tests ordered significantly increased from 8.7 per 100 encounters in Period 1, to 10.2 per 100 in Period 2. Extrapolation of this result suggests an average 8.45 million imaging tests ordered by GPs per year in Period 1 and 12.23 million per year in Period 2, an increase of 44.7%, equating to approximately 3.78 million more orders per year over the 3 years in Period 2 than in the years of Period 1. With respect to the guidelines current ordering behaviour for new back problems, shoulder sprains/strains, knee problems, and knee sprains/strains, has room for improvement, according to the researchers.  The results were not entirely unexpected. There has long been a concern about unnecessary test ordering. In a paper published in 2008 unnecessary laboratory tests may be defined as those that have a ‘vanishingly small’ chance of:

  • revealing any unexpected pathological process.
  • contributing to the diagnosis of the cause of a patient’s presenting symptoms.
  • assisting in the monitoring of the progress of a known pathological process.
  • helping to assess the management of a known disease process.

An interesting insight is offered:

The millions of dollars spent on unnecessary tests are, in [doctors’] minds, balanced against the tens of millions involved in adverse court judgments.

In this context I recently asked colleagues what test they would perform on me if I presented as ‘tired all the time’, adding that I had no physical signs, was not depressed and was not taking anything (prescribed or otherwise) that would account for my fatigue. The answer was unanimous-‘Thyroid function test’. This was based on published advice on the approach to such patients:

However, even though laboratory evaluations rarely play a crucial role, they should be used to exclude underlying organic illness.

So, I asked my colleagues how they would interpret the findings if my results were found to be just over the limit of normal. What, in their view was the probability that I have hypothyroidism? ‘High’ came the answer. ‘We would put you on thyroxine.’ The published data suggests that the positive predictive value of tests on people in this context is  less than 12%. Which means it is highly unlikely that I have anything physical wrong with me, much less that I need to take thyroxine. At a time when there is an increasing demand for GP services, it is going to be helpful for colleagues to be aware of the positive predictive value of the tests they order and to share that information with patients before recommending tests. The article listing laboratory tests to screen for a host of highly unlikely conditions assumes that the doctor has spoken to and examined the patient and that the indications for the tests are based on specific clinical findings.  In most cases the patient who has a life limiting pathology does not look or feel well. However every patient needs to know what the test results mean- they are often meaningless and place the patient in harms way. The approach in the Dutch paper to postpone tests for 4 weeks resulted in benefit to people with unexplained fatigue who may otherwise have been harmed by further investigation of equivocal test results. The study is testimony to what  can be achieved by practitioners sharing information with patients while harnessing the power of observation, applying a little bit of science and dispensing a tincture of common sense.

Picture by Send me adrift.

2 thoughts on “Innovating without inventing something new”

  1. Using the example of (presumably) a TSH reading just over 4 or 5 in the context of long standing tiredness, if I understand you correctly, there is a lot you can do to clarify the situation. The first is to compare with previous results if these exist, to see if they are in the same quartile of the reference range. The next is to get a fT4 level, as the relative positions in the ranges (or a ratio of the results) of TSH and fT4 is a better guide. If they are high and low respectively, that is very suspicious. If suspicion remains, I use a therapeutic trial of T3 20mcg, see http://www.holistic-doc-pain-supportDOTcom/thyroid-medicine.html and /reference-ranges.html
    People do not get suddenly tired for no reason, but “It’s probably a virus” would be correct a lot of the time and preferable to “I don’t know what is wrong but please wait 4 weeks before we attempt to find out.” You would have to be very careful about how such a policy was explained. Pathology tests would probably be less drain on the public purse than a further consultation with another GP. The path labs get paid for only the most expensive three of tests if more are ordered, if I understand correctly.

  2. Hi James,
    Thanks for taking the time to comment- much appreciated.
    Yes, you are right there is a lot that can be done- not least monitoring the TSH- in most cases it doesn’t move much and the T4 remains euthyroid- not much to be done other than reassure. Nonetheless that was the reaction I received. In my experience people do present as tired without any obvious cause- often it is because I don’t know the whole story- a bully-boy boss, boredom, tension at home, a few sleepless nights about the mortgage etc. The patient doesn’t feel it’s the place to talk about it, or hasn’t made the connection. We do eventually get around to those issues and agree that we are going to monitor the situation. Tests are ordered when things are not resolving-the patient is made to feel that they have been heard and that it hasn’t just been dismissed as ‘a virus’ which many people take as short hand for ‘I don’t really know and( BTW: I’m not interested)’.

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