A medical indication to perform a particular test or to administer a particular treatment may be a medical reason to perform that test or administer that treatment. Stedman’s Medical Dictionary (2005) defines a medical indication as “the basis or rationale for using a particular treatment or diagnostic test,” and says that it “may be furnished by a knowledge of the cause (causal indication), by the symptoms present (symptomatic indication), or by the nature of the disease (specific indication).”1
A medical indication may also be a situation or condition in which a particular test or treatment is advised or recommended, based on the available scientific evidence. For example, according to the Physicians’ Desk Reference (2015), the indications for prescription of an albuterol inhaler include “Treatment or prevention of bronchospasm in patients 4 years of age and older with reversible obstructive airway disease,” and “Prevention of exercise-induced bronchospasm in patients 4 years of age and older.”2
A medical indication may also be an evidence-based justification for a particular test or treatment. The strength of the indication may depend on the strength of the available scientific evidence for that indication.
Factors affecting the indication for a particular test or treatment include not only the nature of the particular disease process under consideration, but also the potential benefits and efficacy of treatment, the age of the patient, the overall condition of the patient, the personal desires and preferences of the patient, the potential side-effects and burdens of treatment for the patient, the costs of treatment, the availability of treatment, and the projected goals of treatment.
A medical non-indication for the performance of a particular test or administration of a particular treatment is an absence or lack of indication to perform that test or administer that treatment. Reasons that medical tests or treatments may not be indicated include: the non-health-threatening nature of some medical conditions, the lack of treatment efficacy with regard to some medical conditions, the potential side-effects of some treatments, the potential financial burdens of some treatments, and the personal desires of some patients not to undergo arduous tests and treatment.
A medical contraindication to a particular test or treatment is a medical reason not to perform that test or treatment (because the test or treatment may be injurious or harmful to the patient). A contraindication may be described as relative or absolute. A relative contraindication to a test or treatment may sometimes be outweighed by the potential benefits of that test or treatment if the potential benefits are significant and the risk of harm is very low, but an absolute contraindication to a test or treatment is never outweighed by the potential benefits of that test or treatment (because of the severity and magnitude of the potential harms that the test or treatment may cause to the patient)
What then is the relation between medical indications and epistemic justifications? To say that a particular test or treatment is medically indicated is to make an epistemic claim regarding the appropriateness, correctness, and advisability of that test or treatment. If we make such a claim, then we may have an epistemic duty to justify it by thoroughly examining all the available evidence for and against it. In order to be epistemically justified in saying that a particular test or treatment is medically indicated, we must have sufficient epistemic grounds for saying so.
Let’s consider the following propositions (where the letter “T” stands for a medical test or treatment) as a method of investigating the role and function of medical indications as epistemic justifications:
1. If T is medically indicated, then it is medically (and epistemically, and ethically) justified.
2. If T is medically indicated, then there are good medical reasons for it that sufficiently outweigh any possible or actual reasons against it.
3. If T is medically indicated, then there is sufficient scientific evidence in favor of it, and there is insufficient scientific evidence against it.
4. If T is medically indicated, then there is sufficient scientific evidence of its benefit, safety, and efficacy.
5. The proposition P that a particular test or treatment T is medically indicated is epistemically justified if there is sufficient scientific evidence in favor of the truth of P.
The above propositions may all have their corresponding negations. Thus, if T is not medically indicated, then it is not medically (and not epistemically, and not ethically) justified, and so on.
To what extent may medical indications differ from epistemic justifications? Medical indications may be more than epistemic justifications, insofar as they may be not only epistemic, but also ethical (and practical) in nature. They may be not only situations or conditions in which particular tests or treatments are said to be appropriate or advisable, but also parameters and guidelines for performing tests and prescribing treatments.
Medical indications may also differ from epistemic justifications insofar as in some cases an argument can be made that a test or treatment may be epistemically (and ethically) justified without clearly being medically indicated (its justification may not be apparent at first glance and may only be apparent on later examination). A test or treatment that was not clearly indicated at first glance may turn out to have an unanticipated beneficial effect. However, such a possibility may still not provide sufficient grounds for the argument that the performance of non-indicated tests or treatments can in some cases be medically justified. The justifiability of a medical test or treatment may in fact depend on the strength, clarity, and sufficiency of the indications for that test or treatment. Tests or treatments that have weak, unclear, or insufficient indications may be medically (and epistemically, and ethically) compromised by their weak, unclear, or insufficient justification.
Non-indication, or lack of indication, for a test or treatment may in some cases be a contraindication to that test or treatment, insofar as that test or treatment may pose unnecessary risks to the patient and may expose the patient to unnecessary harms. Non-indicated tests or treatments may also cause unnecessary financial expenses for patients, for third-party payers, and for a whole healthcare system.
Medical indications may constitute reasons to perform particular tests, procedures, or treatments, based on our knowledge of the potential benefits, safety, and efficacy of those tests, procedures, and treatments, and based on our knowledge of the natural history of the disease processes under consideration. Medical indications may also affirm the usefulness, appropriateness, and rationality of particular tests, procedures, and treatments within the context of particular medical illnesses, disease processes, and conditions.
1Stedman’s Medical Dictionary for the Health Professions and Nursing, Fifth Edition, edited by Thomas Lathrop Stedman (Baltimore: Lippincott Williams & Wilkins, 2005), p. 735.
2PDR, LLC “Full Prescribing Information, ProAir HFA (albuterol sulfate),” 2015, at http://www.pdr.net/full-prescribing-information/proair-hfa?druglabelid=569.