A multiplicative model of the utility of survival duration and health quality.

Survival duration and health quality are fundamentally important aspects of health. A utility model for survival duration and health quality is a model of the subjective value of these attributes. We investigate the hypothesis that the utility (subjective value) of survival duration and health quality is determined by a multiplicative model. According to this model, there are separate subjective scales for the utility of survival duration and health quality. If F(Y) equals the utility of surviving Y years, and G(Q) equals the utility of living in health state Q, then the multiplicative model proposes that F(Y)G(Q) equals the utility of surviving Y years in health state Q. This model provides a simple explanation for several intuitively compelling relationships. First, the distinction between better-than-death and worse-than-death health states corresponds to the assignment of positive or negative utilities to different health states. Second, a zero duration of survival removes any reason to prefer one health state over any other, just as multiplying the utility of health quality by zero eliminates differences between the utilities of different health states. Third, the subjective difference between Y years in pain and Y years free from pain increases as Y increases as if the difference in utility between pain and no pain were being multiplied by the utility of surviving Y years. A critical prediction of the multiplicative model is the hypothesis that preferences between gambles for health outcomes satisfy a property called utility independence. Individual analyses revealed that most subjects satisfy utility independence, thereby supporting the multiplicative utility model. Some subjects appear to violate a fundamental assumption of utility theory: They appear to violate the assumption that a single utility scale represents both the ordinal preference relations between certain outcomes and the subjective averaging that underlies the utility of gambles. The violation is inferred from an inconsistency between preferences for multiattribute outcomes when they are viewed as certain outcomes and when they are viewed as the outcomes of gambles.

Evaluation of a minimal-contact smoking cessation intervention in an outpatient setting.

We examined the ability of a provider-initiated, minimal-contact intervention to modify the smoking behavior of ambulatory clinic patients. Smokers at two outpatient sites were assigned to one of three groups: provider intervention only (PI); provider intervention plus self-help manual (PI/M); and usual care (control) group (C). The physician message emphasized the patient's personal susceptibility, the physician's concern, and the patient's ability to quit (self-efficacy). The nurse consultation concentrated on benefits and barriers associated with stopping, and on strategies for cessation. Telephone interviews were conducted with the 250 participants within a few days of their clinic visit and again at one and six months. Both PI and PI/M proved to be superior to usual care in motivating attempts to quit at both one-month and six-month follow-ups, and logistic regression analyses indicated that participants receiving the self-help manual in addition to the health provider message were between two and three times more likely to quit smoking during the study period than were participants in either of the other study groups.

Beliefs about control of smoking and smoking behavior: a comparison of different measures in different groups.

This study investigated several measures of beliefs about controlling smoking as predictors of cessation and reduction at one and six months after a medically-based control program. Smokers (n = 250 total) attending general medicine clinics at University and Veterans Administration facilities received advice to quit from both physicians and nurses. Beliefs about difficulty resisting urges to smoke in 15 situations, their frequency of occurrence, and general level of difficulty were assessed at baseline. For the University group of patients, significant relationships were found between both general and specific indexes and both cessation and reduction at one month. Although a greater change in smoking was seen at six months, few belief measures remained predictive. At one month, global measures were as useful as specific ones, although difficulty in situations of negative emotion was a consistent and strong predictor. Marked differences between the two sites were found; virtually no measure of difficulty proved predictive for the VA group.

To test or not to test--to treat or not to treat: the decision-threshold approach to patient management.

The inability to consider explicitly factors that should enter into clinical judgment compromises physician efforts to make cost-effective decisions regarding diagnostic testing and treatment. The authors describe the decision-threshold approach, a decision-analysis strategy that helps physicians identify an optimal test-treatment decision based upon the prior probability of disease, the characteristics of the test (sensitivity, specificity, risk), and the benefits/costs of treatment. They also present a microcomputer graphics program that makes the decision-threshold approach readily available to physicians.

Patient medication instruction and provider interactions: effects on knowledge and attitudes.

This prospective study examines whether a patient medication instruction sheet (PMI) given to clinic patients by their health care provider affects knowledge and/or attitudes with thiazide diuretic use as part of an antihypertensive regimen. Adult male patients (N = 285) in a general medicine clinic were assigned to groups receiving the American Medical Association PMI describing their diuretic. Patients getting the PMI obtained it either directly from their provider or at the pharmacy dispensing window. All patients were surveyed by phone 1 week following the clinic visit with regard to the PMI, knowledge of medication use, and attitudes toward drug use. Results indicate that a provider-dispensed PMI results in higher levels of drug knowledge and greater patient satisfaction with their knowledge than a pharmacy-dispensed PMI. In addition, the PMIs educational value may be lessened by an incomplete verbal consult. This study demonstrates that the AMA PMI is an effective educational tool when distributed by a provider and can promote better understanding and use of prescribed medications.

Evaluation of a minimal-contact smoking cessation program in a health care setting.

A controlled evaluation of a minimal-contact smoking cessation intervention was conducted with 213 inpatients and outpatients at a Veterans Administration Medical Center (VAMC). The intervention had three components: Brief consultation from a health practitioner; administration of a self-help smoking cessation manual; and provision of an incentive to adhere to recommendations in the manual. Enrollment procedures differed from those of many other smoking-intervention trials in that, instead of enrolling only smokers who were motivated to quit, all patients who smoked and who would normally be considered eligible for a smoking-cessation intervention were included. The evaluation examined acceptability of the program to patients who smoked, overall effectiveness of the intervention, and efficacy of the intervention for specific patient demographic, social status, and health status groups. The program had a high degree of acceptance by patients who smoked, with over 60% agreeing to participate and take home the self-help smoking-cessation manual. The program was effective in getting patients to reduce their daily smoking, and marginally effective in influencing smoking cessation, with some patient groups exhibiting higher cessation rates than others. Special problems to be considered when attempting to influence groups of smokers at high levels of psychological stress and with low levels of education and income--factors normally associated with high rates of smoking and failure in traditional smoking-cessation programs--are discussed in light of the results obtained.

Psychosocial aspects of changes in cigarette-smoking behavior.

This paper examines the relationships between patients' perceptions of susceptibility to illness, self-efficacy, anxiety, social support and subsequent changes in cigarette-smoking behavior through a prospective study involving 213 patients using a Veterans Administration Medical Center (VAMC). During an inpatient or outpatient visit to the VAMC, veterans received a questionnaire and were then enrolled in a smoking cessation intervention trial wherein some patients received a practitioner-initiated minimal-contact intervention and other patients received usual care. Smoking status was assessed 3 months following hospital discharge. Analyses revealed that patients most likely to have reduced their smoking, whether in the intervention or control group, were those reporting both high perceived susceptibility and high expectations of efficacy. Those least likely to have reduced their smoking were those reporting high susceptibility but low efficacy--what has been characterized as a 'learned helplessness' mode. Expectations of efficacy were inversely associated with general level of anxiety; that is, those reporting high levels of anxiety tended to report lower levels of self-efficacy. This relationship was powerfully buffered by a measure of social support. The results of this study suggest a number of potentially effective counseling strategies for practitioners who are trying to get their patients to quit smoking.

Smoking behavior, cessation techniques, and the health decision model.

The magnitude of the problem of smoking challenges health providers to persuade patients of the importance of trying to quit. Smoking behavior and cessation techniques are discussed in terms of the health decision model, a third-generation model combining health beliefs, decision analysis, and behavioral decision theory. This review suggests the need for physicians to emphasize factors such as health beliefs, self-efficacy, social support, and reduction of stress in smoking cessation efforts. Patients experiencing symptoms, particularly relating to the lungs or heart, may have stronger health beliefs and are clearly more likely to quit smoking. In the absence of a clear-cut advantage for any particular smoking cessation technique, physicians should provide advice about smoking as a regular part of every patient visit.

Parameter estimates for a QALY utility model.

This paper discusses a utility model for quality adjusted life years (QALY). According to this model, the utility of Y years of survival in health state Q is bYrH(Q), where b is a scaling constant and r and H(Q) are parameters. The parameter r is shown to be interpretable as a representation of a patient's risk attitude with respect to survival duration. The parameter H(Q) represents the proportionate reduction in the utility of survival when health state Q prevails. Methods are described for estimating these parameters from the results of an individual patient utility assessment. Results are then reported for empirical estimation of parameters r and H(Q) from the preference judgments of a sample of 46 coronary artery disease patients. In this empirical study, health state Q takes on two values--survival with angina pectoris and survival free from angina pectoris. Estimated values of parameters r and H(Q) are discussed in relation to the decision analysis of coronary artery bypass graft surgery. Finally, it is argued that the model deserves consideration as a medical utility model, despite some preliminary evidence that assumptions of the model are descriptively false, because it provides a simple representation of the utility of survival duration and health quality. These aspects of health outcomes are known to be critically important in the expected utility analysis of health decisions.

Understanding and improving patient compliance.

The problem of patient compliance, as well as the ability of the physician to understand, detect, and improve compliance are described in relation to a new model of health decisions and patient behavior. The health decision model combines decision analysis, behavioral decision theory, and health beliefs. This model provides a framework for modifying general health beliefs; treatment recommendations; experience with therapeutic regimens and health care providers; patient knowledge and social interaction patterns. Physicians, guided by certain ethical restraints, are in a unique position of responsibility and opportunity to actively encourage patient compliance with treatment.

How decisions are reached: physician and patient.

How can physicians consider patient preferences in reaching medical decisions? Physicians may intuitively agree about the importance of considering all significant aspects of alternative therapies, including patient preferences. However, it may be difficult to resolve or quantitate critical trade-offs between benefit and risk, and quality and quantity of life. One way to do this is decision analysis, a systematic approach to decision making under conditions of uncertainty. Behavioral research involving the assessment of values and probabilities may bear on the adequacy of decision analysis and help us to better understand patient preferences in clinical decisions.

The serum digoxin test and digoxin toxicity: a Bayesian approach to decision making.

The clinician may often be uncertain about the presence of digoxin toxicity. This uncertainty is particularly important when the clinician must make initial therapeutic decisions about continuing or discontinuing digoxin. We describe a method that helps to clarify the role of the serum digoxin test in decreasing the uncertainty surrounding the diagnosis and treatment of toxicity. The relation between the test and toxicity was first determined in our patient population. An approach to the interpretation of the test based on the likelihood ratio was then developed by combining our data with selected data from the literature. The relation between the pretest risk of toxicity (the estimated risk of toxicity in the population under investigation before the test result is known) and the predictive value of the test was established. This relation was also used to analyze the importance of the degree of elevation of the test. The appropriate threshold probability for institution of treatment of toxicity was then determined by an interview technique. The test was able to make the patient's probability of toxicity cross the threshold probability for treatment of toxicity for an intermediate range of pretest risk. Our analysis suggests that the serum digoxin test may have a critical effect on therapeutic decisions and can be best considered as contributing to the spectrum of risk.

Assessment of patients' preferences for therapeutic outcomes.

We sought to characterize patients' preferences in drug therapy decisions with uncertain outcomes by analyzing their responses to hypothetical therapeutic scenarios. In each scenario, the patient chose between two drugs with equivalent effects, one having two possible outcomes occurring by chance (uncertain outcome) and the other having a single outcome (certain outcome). Most patients chose a certain and intermediate therapeutic effect rather than taking a chance between no effect and a very large favorable effect. When the outcomes were adverse drug effects, there was a strong opposite trend. Rather than preferring a certain and intermediate adverse drug effect, most patients were willing to risk a possible severe drug side effect in order to have a chance of experiencing no adverse reaction. Thus, patients' willingness to accept risks in therapy decisions involving uncertain outcomes may depend on whether the outcomes are favorable or unfavorable.

Complete heart block with hyperthyroidism.

Thyrotoxicosis developed in a patient while receiving thyroid hormone therapy for clinical hypothyroidism. The development of second-degree heart block of Mobitz type 1 variety was followed by third- and then first-degree heart block. We conclude that the varying degrees of heart block were secondary to hyperthyroxinemia caused by Graves' disease and exogenous thyroid hormone.