We have discussed the diagnostic methods used by practitioners of alternative medicine several times before (see for instance here, here, here, here, here and here). Now a new article has been published which sheds more light on this important issue.
The authors point out that the so-called alternative medicine (SCAM) community promote and sell a wide range of tests, many of which are of dubious clinical significance. Many have little or no clinical utility and have been widely discredited, whilst others are established tests that are used for unvalidated purposes.
- The paper mentions the 4 key factors for evaluation of diagnostic methods:
Analytic validity of a test deﬁnes its ability to measure accurately and reliably the component of interest. Relevant parameters include analytical accuracy and precision, susceptibility to interferences and quality assurance.
- Clinical validity deﬁnes the ability to detect or predict the presence or absence of an accepted clinical disease or predisposition to such a disease. Relevant parameters include sensitivity, speciﬁcity, and an understanding of how these parameters change in different populations.
- Clinical utility refers to the likelihood that the test will lead to an improved outcome. What is the value of the information to the individual being tested and/or to the broader population?
- Ethical, legal and social implications (ELSI) of a test. Issues include how the test is promoted, how the reasons for testing are explained to the patient, the incidence of false-positive results and incorrect diagnoses, the potential for unnecessary treatment and the cost-effectiveness of testing.
The tests used by SCAM-practitioners range from the highly complex, employing state of the art technology, e.g. heavy metal analysis using inductively coupled plasma-mass spectrometry, to the rudimentary, e.g. live blood cell analysis. Results of ‘SCAM tests’ are often accompanied by extensive clinical interpretations which may recommend, or be used to justify, unnecessary or harmful treatments. There are now a small number of laboratories across the globe that specialize in SCAM testing. Some SCAM laboratories operate completely outside of any accreditation programme whilst others are fully accredited to the standard of established clinical laboratories.
In their review, the authors explore SCAM testing in the United States, the United Kingdom and Australia with a focus on the common tests on offer, how they are reported, the evidence base for their clinical application and the regulations governing their use. They also review proposed changed to in-vitro diagnostic device regulations and how these might impact on SCAM testing.
The authors conclude hat the common factor in all these tests is the lack of evidence for clinical validity and utility as used in SCAM practice. This should not be surprising since this is true for SCAM practice in general. Once there is a sound evidence base for an intervention, such as a laboratory test, then it generally becomes incorporated into conventional medical practice.
The paper also discusses possible reasons why SCAM-tests are appealing:
- Adding an element of science to the consultation. Patients know that conventional medicine relies heavily on laboratory diagnostics. If the SCAM practitioner orders laboratory tests, the patient may feel they are beneﬁting from a scientiﬁc approach.
- Producing material diagnostic data to support a diagnosis. SCAM lab reports are well presented in a format that is attractive to patients adding legitimacy to a diagnosis. Tests are often ordered as large proﬁles of multiple analytes. It follows that this will increase the probability of getting results outside of a given reference interval purely by chance. ‘Abnormal’ results give the SCAM practitioner something to build a narrative around if clinical ﬁndings are unclear. This is particularly relevant for patients who have chronic conditions, such as CFS or ﬁbromyalgia where a deﬁnitive cause has not been established and treatment options are limited.
- Generating business opportunities using abnormal results. Some practitioners may use abnormal laboratory results to justify further testing, supplements or therapies that they can offer.
- By offering tests that are not available through traditional healthcare services some SCAM practitioners may claim they are offering a unique specialist service that their doctor is unable to provide. This can be particularly appealing to patients with unexplained symptoms for which there are a limited range of evidenced-based investigations and treatments available.
Regulation of SCAM laboratory testing is clearly deﬁcient, the authors of this paper conclude. Where SCAM testing is regulated at all, regulatory authorities primarily evaluate analytical validity of the tests a laboratory offers. Clinical validity and clinical utility are either not evaluated adequately or not evaluated at all and the ethical, legal and social implications of a test may only be considered on a reactive basis when consumers complain about how tests are advertised.
I have always thought that the issue of SCAM tests is hugely important; yet it remains much-neglected. A rubbish diagnosis is likely to result in a rubbish treatment. Unreliable diagnostic methods lead to false-positive and false-negative diagnoses. Both harm the patient. In 1995, I thus published a review that concluded with this warning “alternative” diagnostic methods may seriously threaten the safety and health of patients submitted to them. Orthodox doctors should be aware of the problem and inform their patients accordingly.
Sadly, my warning has so far had no effect whatsoever.
I hope this new paper is more successful.