Too Earnest about Evidence

Inspired by observation and inequity… and a question from a patient in my clinic yesterday.

In 1996 Sackett et al wrote an editorial in the BMJ titled:[1]

Evidence based medicine: what it is and what it isn’t.

The subtitle ran thus:

It’s about integrating individual clinical expertise and the best external evidence.

Note that individual clinical expertise is the first thing in the sentence, not best external evidence. Why is that? Because, to quote further from the same editorial:

Good doctors use both individual clinical expertise and the best available external evidence, and neither alone is enough. Without clinical expertise, practice risks becoming tyrannised by evidence, for even excellent external evidence may be inapplicable to or inappropriate for an individual patient. Without current best evidence, practice risks becoming rapidly out of date, to the detriment of patients.

My patient was a healthy-looking late octogenarian. She gave a history of medial scapula pain that had been treated by a famous medical acupuncturist in London some 50 years ago. He had to treat her 5 times before the pain disappeared. He treated her foot first then the top of her neck, and then other places that she could not recall, but never treated the painful area directly. Her pain had gone away for a year or so, and she had suffered on and off since. In the past she could reach a tender spot just medial to the left scapula at the level of the scapula spine. When the needle had been placed in her foot, the tender spot disappeared.

I had seen her some months ago and attempted to find a trigger point band in the rhomboids or mid trapezius. I could find bands of course, but she was never sure that I was on the right spot.

On this occasion, sensing the hope of the patient and with her consent, I tried to reproduce the sort of minimal treatment she described and I had read about from this renowned colleague.[2,3] Afterwards she asked me if he used meridians. He may well have done when he first treated her some 50 years ago. I tried to explain his vision, and how he came to change, and the profound effect this had on the practice of medical acupuncture in the UK.

Felix made careful observations in his own practice and systematically tested his ideas and assumptions. It was not what we now think of as evidence, but it was probably the best he had to go on at the time.

Without clinical expertise, practice risks becoming tyrannised by evidence

Surely now I have more to go on. First I must find a label to attach to my singular late octogenarian lady. Without a label I cannot search for evidence. Should I call it “medial scapula pain” or “dorsal back pain”? Well there are no systematic reviews or even RCTs with this combination of words in the title to be found on PubMed. Indeed there are no papers whatsoever.

So I could just go for “back pain”[ti] AND acup* – I will certainly get some reviews (57 today in fact) but how is that going to help me treat this patient? The best external evidence often tells me that there is little support for any interventions in the category labels I attach to most of my patients. Even if she had “back pain” as a label, she is not likely to be represented in the population samples tested. She would doubtless be excluded for age and comorbidities.

In the absence of external evidence from systematic reviews or RCTs I must rely on ideas developed from study of basic sciences [the best external evidence] together with clinical judgement. But am I allowed to do that in contemporary practice?

Sackett et al commented over 20 years ago:

Some fear that evidence based medicine will be hijacked by purchasers and managers to cut the costs of health care. This would not only be a misuse of evidence based medicine but suggests a fundamental misunderstanding of its financial consequences. Doctors practising evidence based medicine will identify and apply the most efficacious interventions to maximise the quality and quantity of life for individual patients; this may raise rather than lower the cost of their care.

I will leave the reader to judge what happened since Sackett.

The clue is in the title 😉

References

1         Sackett DL, Rosenberg WM, Gray JA, et al. Evidence based medicine: what it is and what it isn’t. BMJ 1996;312:71–2.

2         Mann F. Reinventing Acupuncture: A New Concept of Ancient Medicine. 1st ed. Oxford: Butterworth Heinemann 1992.

3         Mann F. Reinventing Acupuncture: A New Concept of Ancient Medicine. 2nd ed. Oxford: Butterworth Heinemann 2000.