Randomised controlled trials are needed

EDITOR,—It is still unclear from the literature whether investigative tests reassure patients with anxieties about the presence of serious disease.1 2 Ray Fitzpatrick discusses some of the possible reasons for this, including psychiatric morbidity, poor communication, and the “wild card effects” mentioned in the study by I G McDonald and colleagues.3

Other psychological processes in patients are also likely to influence outcome: early childhood experiences of illness, particularly when associated with lack of parental care, are a powerful risk factor for adult somatisation, and the accuracy of patients' medical knowledge and other cognitive errors such as catastrophic thinking4 are likely to influence the effectiveness of investigations to reassure.

The decision to investigate may also reflect a physician's obsessive fear of missing organic disease and an inability to cope with any diagnostic uncertainty, which will give patients mixed messages about their symptoms. Physicians may find it particularly difficult to communicate equivocal results to the patient because equivocal findings increase doctors' anxieties about diagnosis. Any reassurance that the patient derives from normal results of investigations may then be negated by the continued prescription of drug treatment: cardiac drugs have been prescribed for up to half of patients with normal coronary arteries despite there being no medical indication.5

Examination of the methodology used in the studies in this area can also explain the conflicting results in the literature. Few investigators have used objective measures of reassurance, such as patients' subsequent use of medical services or functional disability, or standardised measures of anxiety or health beliefs. The most rigorous way to test the hypothesis that a particular test does or does not reassure patients with no serious disease is a randomised controlled trial of that test. There have been few randomised controlled trials in this area even though, as Fitzpatrick points out, “reassuring patients who have unwarranted concerns that they are seriously ill is one of the commonest medical tasks.”