The contribution of a non-invasive test to clinical care. The impact of echocardiography on diagnosis, management and patient anxiety

The Value of Diagnostic Information to Patients with Chest Pain Suggestive of Coronary Artery Disease

Background. The results of diagnostic tests often have a profound impact on the way patients view their health. Decision analyses and clinical guidelines do not routinely consider this, in part because methods are not well developed for measuring the value of testing to patients. Objectives. To measure the value of stress testing to patients with chest pain suggestive of coronary artery disease (CAD) and to improve methods for measuring the value of diagnostic information. Methods. The authors conducted a prospective cohort study of patients with chest pain who were referred from 44 primary care practices for treadmill testing (N = 320). Current health status, perceived life expectancy, anxiety, uncertainty, and preferences for current health states were measured before and 1 week after testing and receipt of the results. Patients also reported the diagnosis given by their physicians after testing. The authors used paired t tests to assess changes before and after testing. Results. Perceived life expectancy lengthened, anxiety decreased, and uncertainty decreased 1 week after exercise testing, compared to before (P < 0.01). For many patients, sytoms were less bothersome after testing than before. There were few changes in perceptions of current health status, as measured by the SF-36. The authors found evidence of reassurance among patients who reported that CAD had been excluded and no evidence of psychological harm among patients who reported a new CAD diagnosis. Conclusions. Patients experienced measurable psychological benefits from noninvasive diagnostic testing for CAD. Similar measurements should be standard components of diagnostic test evaluation.

The potential of a placebo/nocebo effect in pharmacogenetics

Pharmacogenetic testing holds great promise to improve health outcomes and reduce adverse drug responses through enhanced selection of therapeutic agents. Since drug responses can be manipulated by verbal suggestions, it is of particular interest to understand the potential impact of pharmacogenetic test results on drug response. Placebo and nocebo-like effects may be possible due to the suggestive nature of pharmacogenetic information that a drug will or will not likely lead to improved health outcomes. For example, pharmacogenetic testing could provide further reassurance to patients that a given drug will be effective and/or cause minimal side effects. However, pharmacogenetic information could adversely affect drug response through negative expectations that a drug will be less than optimally effective or cause an adverse response, known as a nocebo-like effect. Therefore, a patient's perceived value of testing, their understanding of the test results, and the manner in which they are communicated may influence therapeutic outcome. As such, physicians should consider the potential effect of pharmacogenetic test results on therapeutic outcome when communicating results to patients. Studies are needed to investigate the impact of pharmacogenetic information of therapeutic outcome.

Cardiac disease construction on the borderland

The diagnosis of possible heart disease in the well patient has undergone remarkable shifts over the past century. The traditional medical view places strong emphasis on the contribution of technological data to the diagnosis of disease. In the case of serious heart disease, cardiac diagnostic technologies can play a defining role but, more often in the clinical context, patients are assessed for heart disease which is minor. The question is whether disease is present at all. In this borderland between health and disease, the interpretation of technological data is inherently uncertain. The diagnosis then depends more heavily on the social utility of particular disease categories. Shifts in diagnostic categorisation are not therefore attributable solely to more extensive forms of cardiac imaging but are socially constructed in an interactive context which involves the technology, the medical profession and the wider social structures which exist at the time of diagnosis. Claims of technological certainty create a social space within which the medical profession generates disease categories. These shifting disease categories may serve the needs of patients but may also be influenced by those of other players.

The use and interpretation of commercial APC gene testing for familial adenomatous polyposis

BACKGROUND

The use of commercially available tests for genes linked to familial cancer has aroused concern about the impact of these tests on patients. Familial adenomatous polyposis is an autosomal dominant disease caused by a germ-line mutation of the adenomatous polyposis coli (APC) gene that causes colorectal cancer if prophylactic colectomy is not performed. We evaluated the clinical use of commercial APC gene testing.

METHODS

We assessed indications for APC gene testing, whether informed consent was obtained and genetic counseling was offered before testing, and the interpretation of the results through telephone interviews with physicians and genetic counselors in a nationwide sample of 177 patients from 125 families who underwent testing during 1995.

RESULTS

Of the 177 patients tested, 83.0 percent had clinical features of familial adenomatous polyposis or were at risk for the disease-both valid indications for being tested. The appropriate strategy for presymptomatic testing was used in 79.4 percent (50 of 63 patients). Only 18.6 percent (33 of 177) received genetic counseling before the test, and only 16.9 percent (28 of 166) provided written informed consent. In 31.6 percent of the cases the physicians misinterpreted the test results. Among the patients with unconventional indications for testing, the rate of positive results was only 2.3 percent (1 of 44).

CONCLUSIONS

Patients who underwent genetic tests for familial adenomatous polyposis often received inadequate counseling and would have been given incorrectly interpreted results. Physicians should be prepared to offer genetic counseling if they order genetic tests.

Opening Pandora's box: the unpredictability of reassurance by a normal test result

OBJECTIVES

To determine the rate of failure of patient reassurance after a normal test result and study the determinants of failure.

DESIGN

Replicated single case study with qualitative and quantitative data analysis.

SETTING

University teaching hospital.

SUBJECTS

40 consecutive patients referred for echocardiography either because of symptoms (10 patients) or because of a heart murmur (30). 39 were shown to have a normal heart.

INTERVENTIONS

Medical consultations and semistructured patient interviews were tape recorded. Structured interviews with consultant cardiologists were recorded in survey form.

MAIN OUTCOME MEASURES

Patient recall of the explanation and residual understanding, doubt, and anxiety about the heart after the test and post-test consultation.

RESULTS

All 10 patients presenting with symptoms were left with anxiety about the heart despite a normal test result and reassurance by the consultant. Of 28 patients referred because of a murmur but shown to have no heart abnormality, 20 became anxious after detection of the murmur; 11 had residual anxiety despite the normal test result.

CONCLUSIONS

Reassurance of the "worried well"-anxious patients with symptoms or patients concerned by a health query resulting from a routine medical examination or from screening-constitutes a large part of medical practice. It seems to be widely assumed that explaining that tests have shown no abnormality is enough to reassure. The results of this study refute this and emphasise the importance of personal and social factors as obstacles to reassurance.

The appropriateness of use and the clinical impact of micturating cystourethrography in paediatric practice

STUDY OBJECTIVE

To determine the appropriateness of use and the clinical impact of micturating cystourethrography (MCU) in paediatric practice.

DESIGN

Retrospective medical record review.

SETTING

A major teaching children's hospital in the Trent region.

PATIENTS

Consecutive sample of 120 children undergoing MCU during 1991-1992, identified from the radiology records.

MAIN OUTCOME MEASURES

The referring clinician's reasons for requesting an MCU; the clinical management plan pursued before and after the MCU, and the change in management initiated by the result of the examination; the appropriateness of use of the test, as determined by the presence or absence of a valid indication for MCU in the specific clinical situation.

RESULTS

The change in patient management attributable to the MCU result could be categorized as: no change (19%); decision to end the imaging investigation of the patient (33%); decision to end all investigations, and prophylactic or therapeutic interventions (16%); decision to discontinue chemoprophylaxis (2%); decision to end the imaging investigation and introduce chemoprophylaxis and follow-up for bacteriuria (6%); decision to continue the imaging investigation and introduce chemoprophylaxis and follow-up for bacteriuria (13%); and decision to operate or help in planning the surgical treatment required (11%). Inappropriate use of the test was observed in 20% of the cases.

CONCLUSIONS

This study provides a basis for understanding the use of MCU in paediatric practice. The findings that 19% of the cystourethrograms had no appreciable effect, and that 20% of the examinations were used inappropriately show the need for increased effort to minimize overuse of the test.

The clinical utility of transcranial Doppler ultrasound in suspected vertebrobasilar ischemia

The impact of transcranial Doppler ultrasound (TCD) on the management of 107 consecutively referred patients with suspected vertebrobasilar ischemia was studied. Physicians who referred patients for TCD of the posterior circulation were interviewed before and after being given the results of the TCD examination. Management plans devised prior to knowledge of the TCD results were compared to those devised after TCD results were given. Management changed in 42% of the patients after TCD results were given, and there was a 58% reduction in the use of angiography (p = 0.04) and a 128% increase in the use of aspirin (p = 0.005). Changes in the use of anticoagulants and other diagnostic or therapeutic approaches were not significant. TCD appears to have a significant impact on the management of patients with suspected vertebrobasilar ischemia.

Research methods for obtaining primary evidence

The use of new therapeutic and diagnostic technologies has become commonplace in modern medical practice. To avoid both clinical disappointment and the waste of money, health, and lives, the introduction of these technologies will have to be based on evidence that these technologies will do more good than harm. The evidence supporting their use should be derived using research methods designed to deal with placebo effects, confounders, and biases. Some of these methods, and the rationale for their use, are discussed in this article. Although the value of evidence derived from randomized controlled trials is stressed, the importance of reviewing critically the methodological details of such trials and interpreting their results with caution is emphasized. The benefits and risks of relying on case-control and cohort studies are reviewed.

Utility of echocardiography in patients with suspected mitral valve prolapse

PURPOSE

Echocardiography has become a widely utilized test since its introduction into clinical medicine in the early 1970s. Although it has frequently been performed in patients suspected of having mitral valve prolapse (MVP), its usefulness in this setting has not been systematically studied. To investigate the use and value of echocardiography in patients suspected of having MVP, we conducted a prospective study in which physicians were interviewed before and after ordering echocardiographic testing for patients in whom there was a suspicion of MVP.

PATIENTS AND METHODS

The study population included consecutive patients referred to the echocardiography laboratory at Boston University Medical Center because of suspected MVP between January 1 and December 31, 1987. Two standardized telephone interviews were conducted with the physician most responsible for ordering the echocardiogram. The following information was obtained during the first interview, which was always conducted before the echocardiogram was performed: patient demographic and clinical data; the reason for ordering the echocardiogram; the physician's most likely clinical diagnosis; the physician's estimate of the likelihood that the patient had MVP; and the physician's proposed management plans. After the referring physician received the echocardiographic results, a second interview was conducted to determine changes in the most likely clinical diagnosis and management plans. The impact of the echocardiogram on diagnosis and management was evaluated by comparing physician responses before and after reception of echocardiographic results. Receiver operating characteristic (ROC) curves were constructed to assess the physician's skills at distinguishing patients with echocardiographic-documented MVP from those without MVP.

RESULTS

A total of 106 echocardiograms were ordered by 45 different physicians. More than 80% of all echocardiograms were ordered to address diagnostic or therapeutic concerns. On echocardiography, 47 (44%) patients were found to have MVP, six (6%) had mitral regurgitation without prolapse, and 53 (50%) had normal results. On the basis of the ROC curve analysis, the physician's ability to discriminate between patients with and without echocardiographic MVP varied significantly by physician specialty and practice setting. The echocardiographic results led to a change in diagnosis in 59 (56%) patients. A change in management occurred in 29 (27%) patients, with 25 of these 29 changes (86%) related to the initiation or discontinuation of antibiotics.

CONCLUSIONS

Echocardiography frequently alters diagnostic assessments and leads to therapeutic changes in some patients suspected of having MVP. However, the benefits of such changes have not yet been demonstrated.