Treatment decisions under ambiguity

Behavioural 'nudging' interventions to reduce low-value care for low back pain in the emergency department (NUDG-ED): protocol for a 2×2 factorial, before-after, cluster randomised trial

INTRODUCTION

Opioids and imaging are considered low-value care for most people with low back pain. Yet around one in three people presenting to the emergency department (ED) will receive imaging, and two in three will receive an opioid. NUDG-ED aims to determine the effectiveness of two different behavioural 'nudge' interventions on low-value care for ED patients with low back pain.

METHODS AND ANALYSIS

NUDG-ED is a 2×2 factorial, open-label, before-after, cluster randomised controlled trial. The trial includes 8 ED sites in Sydney, Australia. Participants will be ED clinicians who manage back pain, and patients who are 18 years or over presenting to ED with musculoskeletal back pain. EDs will be randomly assigned to receive (i) patient nudges, (ii) clinician nudges, (iii) both interventions or (iv) no nudge control. The primary outcome will be the proportion of encounters in ED for musculoskeletal back pain where a person received a non-indicated lumbar imaging test, an opioid at discharge or both. We will require 2416 encounters over a 9-month study period (3-month before period and 6-month after period) to detect an absolute difference of 10% in use of low-value care due to either nudge, with 80% power, alpha set at 0.05 and assuming an intra-class correlation coefficient of 0.10, and an intraperiod correlation of 0.09. Patient-reported outcome measures will be collected in a subsample of patients (n≥456) 1 week after their initial ED visit. To estimate effects, we will use a multilevel regression model, with a random effect for cluster and patient, a fixed effect indicating the group assignment of each cluster and a fixed effect of time.

ETHICS AND DISSEMINATION

This study has ethical approval from Southwestern Sydney Local Health District Human Research Ethics Committee (2023/ETH00472). We will disseminate the results of this trial via media, presenting at conferences and scientific publications.

TRIAL REGISTRATION NUMBER

ACTRN12623001000695.

Health care provider decision-making and the quality of maternity care: An analysis of postpartum care in Kenyan hospitals

Evidence suggests that health care providers' non-adherence to clinical guidelines is widespread and contributes to poor patient outcomes across low- and middle-income countries. Through observations of maternity care in Kenya, we found limited adherence to guideline-recommended active monitoring of patients for signs of postpartum hemorrhage, the leading cause of maternal mortality, despite providers' having the necessary training and equipment. Using survey vignettes conducted with 144 maternity providers, we documented evidence consistent with subjective risk and perceived uncertainty driving providers' decisions to actively monitor patients. Motivated by these findings, we introduced a simple model of providers' decision-making about whether to monitor a patient, which may depend on their perceptions of risk, diagnostic uncertainty, and the value of new information. The model highlights key trade-offs between gathering diagnostic information through active monitoring versus waiting for signs and symptoms of hemorrhage to manifest. Our work provides a template for understanding provider decision-making and could inform interventions to encourage more proactive obstetric care.

Decision thresholds with genetic testing

A genetic test is a test for the presence or absence of a genetic mutation. A positive test outcome that reveals a mutation associated with increased risk for a disease may lead a patient to seek preventive treatment provided that the penetrance (probability of developing the disease given the mutation) is sufficiently high. We derive the test threshold and the test-treatment threshold, which confine the mutation probability interval for the use of the genetic test. Test and treatment costs as well as a low penetrance rate of the mutation narrow this interval. We illustrate the model with parameters of the test for BRCA1 and BRCA2 genes as well as of preventive treatment options for breast cancer.

Decision Thresholds for Medical Tests Under Ambiguity Aversion

We consider medical decision-making under diagnostic and therapeutic uncertainty and analyze how ambiguity aversion affects the decisions to test and treat, thereby contributing to the understanding of the observed heterogeneity of such decisions. We show that under diagnostic ambiguity (i.e., the probability of disease is ambiguous), prior testing becomes more attractive if the default option is no treatment and less so if the default option is treatment. Conversely, with therapeutic ambiguity (i.e., the probability of a successful treatment is ambiguous), ambiguity aversion reduces the tolerance toward treatment failure so that the test option is chosen at a lower probability of failure. We differentiate between conditional and unconditional ambiguity aversion and show that this differentiation has implications for the propensity to test. We conclude by discussing the normative scope of ambiguity aversion for the recommendations and decisions of regulatory bodies.

Informed Consent from a Historical, Societal, Ethical, Legal, and Practical Perspective

Informed consent is often perceived as a regulatory obligation without recognizing its educational potential in the dynamic provider/patient relationship. This article discusses the complex interaction of ethics, society, and law through a historical and practical perspective. The purpose is to provide general dentists and specialists with a comprehensive understanding of the complexity and practical dimensions of informed consent.

Ambiguity aversion: bibliometric analysis and literature review of the last 60 years

We conduct a bibliometric analysis and review the literature of the last six decades on ambiguity aversion. Comparing trends in theoretical, experimental, and empirical contributions, our study presents the main aspects that are discussed in this literature. We show the increasing relevance of ambiguity aversion for decision-making research and discuss factors influencing attitudes on ambiguity. Our literature review reveals unsolved problems in the research on ambiguity and gives an outlook on new ventures for future research.

On the effect of uncertainty on personal vaccination decisions

This study investigates the effect of ambiguity on personal vaccination decisions. We first characterize the vaccination decision in the absence of ambiguity. We then show that uncertainty about the probability of side effects and the efficacy of the vaccine always reduces take-up under ambiguity aversion. However, uncertainty about the underlying disease, being the probability of sickness or the probability of a severe course of disease, may either encourage or discourage vaccination. Our results are relevant for policy because reducing uncertainty associated with the vaccine always has the desired effect whereas reducing uncertainty associated with the disease may have unintended consequences.

Reducing the relative value of cigarettes: Considerations for nicotine and non-nicotine factors

Despite notable progress in recent decades, cigarette smoke persists as a leading cause of premature death and preventable disease. To weaken the link between nicotine reinforcement and the toxicity associated with combusted tobacco, the United States Food and Drug Administration is considering a product standard targeting cigarette nicotine content. In this review, we summarize research assessing the potential impacts of reducing nicotine in cigarettes. Evidence to date suggests cigarette smoking, toxicant exposure and dependence would decline following substantial reductions in nicotine content. However, reduced nicotine content may not eliminate smoking entirely. Regulatory efforts that shape the nicotine and tobacco marketplace should consider that non-nicotine reinforcing factors and decision-making biases can contribute to the value of smoking. The impact of reducing nicotine in cigarettes will likely depend on the alternative nicotine products available to current smokers. This article is part of the special issue on 'Contemporary Advances in Nicotine Neuropharmacology'.

The treatment decision under uncertainty: The effects of health, wealth and the probability of death

Medical treatment reduces diagnostic risk, increases therapeutic risk and lowers the probability of death. This paper analyzes the effects of initial health, wealth and the probability of death on the propensity to treat under diagnostic and therapeutic risk. It shows that treatment propensity increases with the probability of death, but can decrease with the severity of illness. The effect of wealth depends on the cross-derivative of the utility function with respect to health and wealth. These results have implications for treatment decisions at the end of life.

The willingness to pay for health improvement under comorbidity ambiguity

Accumulated medical information is necessary to determine comorbidity risk between a primary disease and secondary diseases. However, medical decisions often must be made without conclusive evidence because individuals do not have sufficient information. By introducing ambiguity regarding comorbidities, we describe situations in which individuals face a set of plausible comorbidity risks that determines the correlations between primary and secondary diseases. This study examines the conditions under which the willingness to pay for health improvement is larger with comorbidity ambiguity than without it. This study also examines the effect of changes in ambiguity and ambiguity aversion on the willingness to pay.

Ambiguity preferences for health

In most medical decisions, probabilities are ambiguous and not objectively known. Empirical evidence suggests that people's preferences are affected by ambiguity. Health economic analyses generally ignore ambiguity preferences and assume that they are the same as preferences under risk. We show how health preferences can be measured under ambiguity, and we compare them with health preferences under risk. We assume a general ambiguity model that includes many of the ambiguity models that have been proposed in the literature. For health gains, ambiguity preferences and risk preferences were indeed the same. For health losses, they differed with subjects being more pessimistic in decision under ambiguity. Utility and loss aversion were the same for risk and ambiguity. Our results imply that reducing the clinical ambiguity of health losses has more impact than reducing the ambiguity of health gains, that utilities elicited with known probabilities may not carry over to an ambiguous setting, and that ambiguity aversion may impact value of information analyses if losses are involved. These findings are highly relevant for medical decision making, because most medical interventions involve losses.

Threshold analysis in the presence of both the diagnostic and the therapeutic risk

The well-established a priori probability of illness threshold in medical decision making, introduced by Pauker and Kassirer (N Engl J Med 293:229-234, 1975; N Engl J Med 302:1109-1117, 1980), involves the diagnostic risk only. We generalize the threshold analysis by adding the therapeutic risk, i.e., in accounting for the risk that a treatment might sometimes fail. We derive a priori probability of illness threshold as a function of the probability of successful treatment, as well as the inverted function, where the successful treatment probability threshold is a function of the a priori probability of illness. The thresholds in the general model are higher than those in the special cases where one of the two risks is absent. Applications show that the changes in the thresholds can be substantial. Our general model might explain empirical findings of much higher thresholds than the Pauker-Kassirer model suggests.

Decision Criterion and Value of Information Analysis: Optimal Aspirin Dosage for Secondary Prevention of Cardiovascular Events

BACKGROUND

In value of information (VOI) calculations, such as the expected value of perfect information (EVPI), partial perfect information (EVPPI), sample information (EVSI) or implementation (EVIM), the maximum expected value criterion defines the decision making criterion for the adoption of decisions for treatments. However, because decision makers are often risk averse, the uncertainty that accompanies a decision problem may influence adoption decisions.

METHODS

VOI estimates were studied based on 2 alternate decision making criteria: 1) maximum expected value and 2) 95% credible intervals. These criteria were applied to a probabilistic minimal lifetime model of incident cardiovascular events and mortality among target patients comparing 2 daily doses of aspirin (81 mg and 325 mg). Model parameters were based on literature reviews and data analyses.

RESULTS

Expected life-years under 81 v. 325 mg of aspirin were estimated to be 14.86 (SE, 0.10) and 14.72 (0.31) respectively, with a difference of 0.14 (0.29). The probability that 81 mg was optimal was estimated to be 67%. Under Decision Criterion 1, EVIM and EVPI were about 233-thousand and 411-thousand years, respectively. Under Criterion 2, EVIM was undefined, as there remains ambiguity about what to implement. Consequently, EVPI becomes the entire 644-thousand years. Also, under Criterion 1, EVSI reaches an asymptote at a sample size of 10,000 per arm, with minimal gains in value beyond a 5,000 person per arm trial. With Criterion 2, a sample size of 10,000 per arm or higher is substantially more valuable than lower sample sizes.

CONCLUSION

Alternative decision criteria for treatment adoption change the VOI. Decision criteria should be justified for VOI analyses. If multiple criteria may be relevant, analysts should complete VOI estimates using multiple criteria.

Antiretroviral pill count and clinical outcomes in treatment-naïve patients with HIV infection

OBJECTIVES

Treatment guidelines recommend single-tablet regimens for patients with HIV infection starting antiretroviral therapy. These regimens might be as effective and cost less if taken as separate drugs. We assessed whether the one pill once a day combination of efavirenz, emtricitabine and tenofovir reduces the risk of disease progression compared with multiple-pill formulations of the same regimen.

METHODS

We selected treatment-naïve patients starting one-, two- or three-pill formulations of this regimen in data from the Antiretroviral Therapy Cohort Collaboration. These patients were followed until an AIDS event or death or until they modified their regimen. We analysed these data using Cox regression models, then used our models to predict the potential consequences of exposing a future population to either a one-pill regimen or a three-pill regimen.

RESULTS

Among 11 739 treatment-naïve patients starting the regimen, there were 386 AIDS events and 87 deaths. Follow-up often ended when patients switched to the same regimen with fewer pills. After the first month, two pills rather than one was associated with an increase in the risk of AIDS or death [hazard ratio (HR) 1.39; 95% confidence interval (CI) 1.01-1.91], but three pills rather than two did not appreciably add to that increase (HR 1.19; 95% CI 0.84-1.68). We estimate that 77 patients would need to be exposed to a one-pill regimen rather than a three-pill regimen for 1 year to avoid one additional AIDS event or death.

CONCLUSIONS

This particular single-tablet regimen is associated with a modest decrease in the risk of AIDS or death relative to multiple-pill formulations.

Negotiating "Unmeasurable Harm and Benefit": Perspectives of General Practitioners and Consultant Pharmacists on Deprescribing in the Primary Care Setting

The use of multiple medicines, known as polypharmacy, poses a risk of harm that is greatest in older adults with multimorbidity. Deprescribing aims to improve health outcomes through ceasing medicines that are no longer necessary or appropriate due to changing clinical circumstances and patient priorities. General practitioners (GPs) and consultant pharmacists (CPs) are well positioned to facilitate deprescribing in primary care in partnership with older adults who present with inappropriate polypharmacy. In this article, we explore GPs' and CPs' views about inappropriate polypharmacy, the reasoning they apply to deprescribing in primary care, and identify factors that support or inhibit this process. Using focus group methodology and the Framework Method for thematic analysis, two major themes were discerned from the data-working through uncertainty and risk perception as a frame of reference. The findings provide important insights when devising methods for advancing and supporting deprescribing in primary care.

How do general practitioners implement decision-making regarding COPD patients with exacerbations? An international focus group study

PURPOSE

To explore the decision-making of general practitioners (GPs) concerning treatment with antibiotics and/or oral corticosteroids and hospitalization for COPD patients with exacerbations.

METHODS

Thematic analysis of seven focus groups with 53 GPs from urban and rural areas in Norway, Germany, Wales, Poland, Russia, the Netherlands, and Hong Kong.

RESULTS

Four main themes were identified. 1) Dealing with medical uncertainty: the GPs aimed to make clear medical decisions and avoid unnecessary prescriptions and hospitalizations, yet this was challenged by uncertainty regarding the severity of the exacerbations and concerns about overlooking comorbidities. 2) Knowing the patient: contextual knowledge about the individual patient provided a supplementary framework to biomedical knowledge, allowing for more differentiated decision-making. 3) Balancing the patients' perspective: the GPs considered patients' experiential knowledge about their own body and illness as valuable in assisting their decision-making, yet felt that dealing with disagreements between their own and their patients' perceptions concerning the need for treatment or hospitalization could be difficult. 4) Outpatient support and collaboration: both formal and informal caregivers and organizational aspects of the health systems influenced the decision-making, particularly in terms of mitigating potentially severe consequences of "wrong decisions" and concerning the negotiation of responsibilities.

CONCLUSION

Fear of overlooking severe comorbidity and of further deteriorating symptoms emerged as a main driver of GPs' management decisions. GPs consider a holistic understanding of illness and the patients' own judgment crucial to making reasonable decisions under medical uncertainty. Moreover, GPs' decisions depend on the availability and reliability of other formal and informal carers, and the health care systems' organizational and cultural code of conduct. Strengthening the collaboration between GPs, other outpatient care facilities and the patients' social network can ensure ongoing monitoring and prompt intervention if necessary and may help to improve primary care for COPD patients with exacerbations.

Health Insurance, Health Savings Accounts and Healthcare Utilization

Assuming symmetric information, we show that a high-deductible health plan (HDHP) combined with a tax-favored health savings account (HSA) induces more savings and less treatment compared with a full coverage plan under reasonable risk preferences. Furthermore, a higher tax subsidy increases savings in any case but decreases medical utilization if and only if treatment expenses are above the deductible. A larger deductible increases savings but does not necessarily decrease healthcare utilization. Whether an HDHP/HSA combination is preferred over a full coverage contract depends on absolute risk aversion. A higher tax advantage increases the attractiveness of an HDHP/HSA combination, whereas the effects of changes in the deductible are ambiguous. The paper shows that a potential regulator needs to carefully set the size of the deductible as only in a certain corridor of the probability of sickness, its effect on aggregate healthcare costs are unambiguously favorable.

Patients' diagnosis decisions in Alzheimer's disease: the influence of family factors

It is surprising to observe that the number of patients receiving a late diagnosis for Alzheimer's disease (AD) remains high even in countries promoting early diagnosis campaigns. We explore the impact of family history and family support on the risks of receiving a delayed diagnosis. We use French data of 1131 patients diagnosed between 1991 and 2005. We find that the presence of AD history in the family increased the risks of receiving a delayed diagnosis. This was true especially when AD history involved brothers, sisters and other relatives (uncles or cousins). The presence of an informal caregiver at the time of the first warning signs reduced the risks of receiving a late diagnosis, regardless of the informal caregiver concerned (spouse, son, daughter etc.). We identify several opportunities for early detection campaigns. Families with history of disease should be targeted. Campaigns should also target isolated patients, who do not benefit from informal care. Our results underline the importance of improving the diagnosis access for old patients and for men.