Views & Reviews No Holds Barred

“Case finding” in dementia is simply screening with no evidence of benefit

BMJ 2014; 349 doi: https://doi.org/10.1136/bmj.g4791 (Published 24 July 2014) Cite this as: BMJ 2014;349:g4791
  1. Margaret McCartney, general practitioner, Glasgow
  1. margaret{at}margaretmccartney.com

The UK dementia czar, Alistair Burns, agrees that population screening for dementia lacks evidence of benefit.1 Therefore, the NHS has not contracted general practitioners in England to “screen” for dementia; rather, the NHS Commissioning Board has contracted GPs using local enhanced services to use “case finding” among groups of patients who are thought to be at higher risk of dementia. 2 3

What’s the difference? After all, approved NHS screening programmes offer their services only to defined subpopulations. Notably, the classic text on screening does not distinguish case finding from population screening in terms of the need for scrutiny or evidence base.

In 1968 Wilson and Jungner defined “selective screening” in their seminal World Health Organization report.4 “We use this term for the screening of selected high-risk groups in the population. It may still be large-scale, and can be considered as one form of population screening.”

Meanwhile, they describe case finding as “that form of screening of which the main object is to detect disease and bring patients to treatment, in contrast to epidemiological surveys,” which, in turn, simply detect and do not treat risk factors or abnormalities.4

A 2008 WHO review of Wilson and Jungner’s work highlighted the need for “scientific evidence of screening programme effectiveness” along with “quality assurance, with mechanisms to minimize potential risks of screening” and a need to “ensure informed choice, confidentiality and respect for autonomy.”5

So how is case finding different from population screening? WHO has described the search for tuberculosis among high risk populations as case finding.6 The term is also used to describe diagnoses made when a patient attends a healthcare provider for an initially unrelated reason—for example, if a person attends with painful knees, noting contributory obesity may lead to a new diagnosis of hypertension. Asking patients about memory problems when they have no related symptoms is, however, very different from a doctor taking note and acting on symptoms or signs of possible memory loss.

There is a lack of an agreed, formal definition of case finding. The dementia case finding programme is a form of population screening. The term case finding is being used when, to all intents and purposes, population screening is taking place—but without the evidence that would have enabled its approval as a screening programme.

Case finding, as used contemporaneously in the NHS, is full of fudge. The hunt for dementia can’t be called a screening programme because it would not meet the standards of the UK National Screening Committee.7 But call it case finding and suddenly there’s no need for evidence that it protects the public against false positives and negatives—or society from the injustice of more resources directed towards the least unwell. This can’t be right. We need a definition to include science and ensure accountability.

Notes

Cite this as: BMJ 2014;349:g4791

Footnotes

  • Competing interests: I have read and understood the BMJ Group policy on declaration of interests and declare the following interests: I’m an NHS GP partner, with income partly dependant on QOF points. I’m a part time undergraduate tutor at the University of Glasgow. I’ve authored a book and earned from broadcast and written freelance journalism. I’m unpaid patron of Healthwatch. I make a monthly donation to Keep Our NHS Public. I’m a member of MedAct. I’m occasionally paid for time, travel, and accommodation to give talks or have locum fees paid to allow me to give talks but never for any drug or public relations company. I was elected to the national council of the Royal College of General Practitioners in 2013.

  • Provenance and peer review: Commissioned; not externally peer reviewed.

  • Follow Margaret McCartney on Twitter, @mgtmccartney

References

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