Background

Dual processing theory of human cognition postulates that reasoning and decision-making can be described as a function of both an intuitive, experiential, affective system (system I) and/or an analytical, deliberative (system II) processing system. To date no formal descriptive model of medical decision-making based on dual processing theory has been developed. Here we postulate such a model and apply it to a common clinical situation: whether treatment should be administered to the patient who may or may not have a disease.

Methods

We developed a mathematical model in which we linked a recently proposed descriptive psychological model of cognition with the threshold model of medical decision-making and show how this approach can be used to better understand decision-making at the bedside and explain the widespread variation in treatments observed in clinical practice.

Results

We show that physician’s beliefs about whether to treat at higher (lower) probability levels compared to the prescriptive therapeutic thresholds obtained via system II processing is moderated by system I and the ratio of benefit and harms as evaluated by both system I and II. Under some conditions, the system I decision maker’s threshold may dramatically drop below the expected utility threshold derived by system II. This can explain the overtreatment often seen in the contemporary practice. The opposite can also occur as in the situations where empirical evidence is considered unreliable, or when cognitive processes of decision-makers are biased through recent experience: the threshold will increase relative to the normative threshold value derived via system II using expected utility threshold. This inclination for the higher diagnostic certainty may, in turn, explain undertreatment that is also documented in the current medical practice.

Conclusions

We have developed the first dual processing model of medical decision-making that has potential to enrich the current medical decision-making field, which is still to the large extent dominated by expected utility theory. The model also provides a platform for reconciling two groups of competing dual processing theories (parallel competitive with default-interventionalist theories).

Thousands of Americans are injured or die each year from adverse drug reactions, many of which are preventable. The burden of harm conveyed by the use of medications is a significant public health problem and, therefore, improving the medication-use process is a priority. Recent and ongoing efforts to improve the medication-use process focus primarily on improving medication prescribing, and not much emphasis has been put on improving medication discontinuation. A formalized approach for rationally discontinuing medications is a necessary antecedent to improving medication safety and improving the nation’s quality of care. This paper proposes a conceptual framework for revising the prescribing stage of the medication-use process to include discontinuing medications. This framework has substantial practice and research implications, especially for the clinical care of older persons, who are particularly susceptible to the adverse effects of medications.

Purpose

To determine how hypnosis and empathic attention during percutaneous tumor treatments affect pain, anxiety, drug use, and adverse events.

Methods

For their tumor embolization or radiofrequency ablation 201 patients were randomized to receive standard care, empathic attention with defined behaviors displayed by an additional provider, or self-hypnotic relaxation including the defined empathic attention behaviours. All had local anesthetic and access to intravenous medication. Main outcome measures were: Pain and anxiety, assessed every 15 min by patient self-report; medication use with 50μg fentanyl or 1 mg midazolam = 1 unit; adverse events, defined as occurrences requiring extra medical attention including systolic blood pressure fluctuations >50mm Hg and surpassing 180 mm Hg or falling below 105 mm Hg, vaso-vagal episodes; cardiac events, and respiratory impairment.

Results

Hypnosis patients experienced significantly less pain and anxiety than standard care and empathy patients at several time intervals and received significantly less median drug units (mean 2.00, interquartile range (IQR)1-4) than standard (mean 3.00; IQR 1.5-5.0; p = 0.0147) and empathy group patients (mean 3.50, IQR; 2.0-5.9; p = 0.0026). 31 of 65 (48%) patients in the empathy group had adverse events, significantly more than those in the hypnosis (8/66 (12%); p=0.0001) and standard care groups (18/70 (26%); p=0.0118).

Conclusions

Procedural hypnosis including empathic attention reduces pain, anxiety, and medication use. Conversely, empathic approaches which provide an external focus of attention and do not enhance patients’ self-coping can result in more adverse events. These findings should have major implications for the education of procedural personnel.

OBJECTIVE

To describe the rate and types of events reported in acute care hospitals using an electronic error reporting system (e-ERS).

DESIGN

Descriptive study of reported events using the same e-ERS between January 1, 2001 and September 30, 2003.

SETTING

Twenty-six acute care nonfederal hospitals throughout the U.S. that voluntarily implemented a web-based e-ERS for at least 3 months.

PARTICIPANTS

Hospital employees and staff.

INTERVENTION

A secure, standardized, commercially available web-based reporting system.

RESULTS

Median duration of e-ERS use was 21 months (range 3 to 33 months). A total of 92,547 reports were obtained during 2,547,154 patient-days. Reporting rates varied widely across hospitals (9 to 95 reports per 1,000 inpatient-days; median=35). Registered nurses provided nearly half of the reports; physicians contributed less than 2%. Thirty-four percent of reports were classified as nonmedication-related clinical events, 33% as medication/infusion related, 13% were falls, 13% as administrative, and 6% other. Among 80% of reports that identified level of impact, 53% were events that reached a patient (“patient events”), 13% were near misses that did not reach the patient, and 14% were hospital environment problems. Among 49,341 patient events, 67% caused no harm, 32% temporary harm, 0.8% life threatening or permanent harm, and 0.4% contributed to patient deaths.

CONCLUSIONS

An e-ERS provides an accessible venue for reporting medical errors, adverse events, and near misses. The wide variation in reporting rates among hospitals, and very low reporting rates by physicians, requires investigation.

Many difficult medical decisions involve uncertainty. Decision analysis—an explicit, normative and analytic approach to making decisions under uncertainty—provides a probabilistic framework for exploring difficult problems in nondeterministic domains. As the methodology has advanced, clinical decision analysis has been applied to increasingly complex medical problems and disseminated widely in the medical literature. Unfortunately, this approach imposes a heavy computational burden on analysts. Microcomputer-based decision-support software can ease this burden.

In this paper we apply the techniques of decision analysis and a standard decision tree folding computer program to the problem of choosing treatment for a patient with an abdominal aortic aneurysm and severe coronary artery disease. Using this methodology, we are able to collate data on the surgical experience and survival of patients with abdominal aortic aneurysms and patients with coronary artery disease, which allowed us to determine the expected utility of aneurysm repair in a patient with both of these diseases.

Clinical problems are often complex, repetitive and time dependent. Using only the classical decision tree formalism to model such details are often impractical if not impossible. A number of techniques are described here that could be used to reduce the complexity and to improve the representation. A case illustration describes how such techniques may be used.

The pitfall of several reviews of noninvasive venous assessment has been the expression of the test data solely in terms of diagnostic accuracy (the number of correct tests in ratio to all tests performed), where results of a test will vary according to disease prevalence. The advantages of receiver operator characteristic curve analysis are twofold: (1) it describes the dynamic relationship between sensitivity (the ratio of the number of true positive tests to the patients with deep venous thrombosis) and specificity (the ratio of true negative tests to the number of patients with no deep venous thrombosis) independent of disease prevalence; and (2) the threshold criteria that defines a positive test can be set by the best balance between sensitivity and specificity and then applied to a given patient population for its diagnostic accuracy.

Venous volume plethysmography is a widely used, simple and rapid method. It was compared to the “gold standard” of phlebography in a prospective blind study of 70 limbs that were clinically suspect of having deep venous thrombosis (DVT). Venous volume displacement plethysmography was defined objectively by three quantitative parameters: (1) maximum venous outflow, (2) integer ratio, and (3) segmental venous capacitance ratio. The DVT (22 to 70 positive phlebograms) was divided by anatomic location into either calf vein DVT or proximal DVT (popliteal vein or above).

By combining these three parameters, a balance between sensitivity and specificity was obtained to provide a rapid, objective method for screening patients with suspected DVT.

The decision which prospective parents face concerning mid-trimester amniocentesis for prenatal diagnosis was examined by decision analysis. The prospective parents' decision depends on the likelihood of the birth of a child affected by a genetic disorder, the risk of amniocentesis, and the probability that the diagnoses provided by the amniocentesis will be correct. The couple's decision must also depend on their attitudes toward each possible outcome. The likelihoods of the outcomes can be obtained from appropriate medical consultation, while the relative costs or burdens of the outcomes should be obtained from the prospective parents. A truly informed decision for this couple can then be formulated from these probabilities and values, thus allowing genetic counseling to be more directive. The technique is illustrated for the prenatal diagnosis of Down's syndrome, meningomyelocele, and Duchenne muscular dystrophy.