Cognitive reflection and antibiotic prescribing for acute respiratory infections

BACKGROUND

Variation in clinical decision-making could be explained by clinicians' tendency to make 'snap-decisions' versus making more reflective decisions. One common clinical decision with unexplained variation is the prescription of antibiotics for acute respiratory infections (ARIs).

OBJECTIVE

We hypothesized that clinicians who tended toward greater cognitive reflection would be less likely to prescribe antibiotics for ARIs.

METHODS

The Cognitive Reflection Test (CRT) is a psychological test with three questions with intuitive but incorrect answers that respondents reach if they do not consider the question carefully. The CRT is scored from 0 to 3, representing the number of correct answers. A higher score indicates greater cognitive reflection. We administered the CRT to 187 clinicians in 50 primary care practices. From billing and electronic health record data, we calculated clinician-level antibiotic prescribing rates for ARIs in 3 categories: all ARIs, antibiotic-appropriate ARIs and non-antibiotic-appropriate ARIs.

RESULTS

A total of 57 clinicians (31%) scored 0 points on the CRT; 38 (20%) scored 1; 51 (27%) scored 2; and 41 (22%) scored 3. We found a roughly U-shaped association between cognitive reflection and antibiotic prescribing. The antibiotic prescribing rate for CRT scores of 0, 1, 2 and 3 for all ARIs (n = 37080 visits) was 32%, 26%, 25% and 30% (P = 0.10); for antibiotic-appropriate ARIs (n = 11220 visits) was 60%, 55%, 54% and 58% (P = 0.63); and for non-antibiotic-appropriate ARIs (n = 25860 visits) was 21%, 17%, 13% and 18%, respectively (P = 0.03).

CONCLUSIONS

In contrast to our hypothesis, there appears to be a 'sweet-spot' of cognitive reflection for antibiotic prescribing for non-antibiotic-appropriate ARIs. Differences in clinicians' cognitive reflection may be associated with other variations in care.

Effect of Behavioral Interventions on Inappropriate Antibiotic Prescribing Among Primary Care Practices: A Randomized Clinical Trial

IMPORTANCE

Interventions based on behavioral science might reduce inappropriate antibiotic prescribing.

OBJECTIVE

To assess effects of behavioral interventions and rates of inappropriate (not guideline-concordant) antibiotic prescribing during ambulatory visits for acute respiratory tract infections.

DESIGN, SETTING, AND PARTICIPANTS

Cluster randomized clinical trial conducted among 47 primary care practices in Boston and Los Angeles. Participants were 248 enrolled clinicians randomized to receive 0, 1, 2, or 3 interventions for 18 months. All clinicians received education on antibiotic prescribing guidelines on enrollment. Interventions began between November 1, 2011, and October 1, 2012. Follow-up for the latest-starting sites ended on April 1, 2014. Adult patients with comorbidities and concomitant infections were excluded.

INTERVENTIONS

Three behavioral interventions, implemented alone or in combination: suggested alternatives presented electronic order sets suggesting nonantibiotic treatments; accountable justification prompted clinicians to enter free-text justifications for prescribing antibiotics into patients' electronic health records; peer comparison sent emails to clinicians that compared their antibiotic prescribing rates with those of "top performers" (those with the lowest inappropriate prescribing rates).

MAIN OUTCOMES AND MEASURES

Antibiotic prescribing rates for visits with antibiotic-inappropriate diagnoses (nonspecific upper respiratory tract infections, acute bronchitis, and influenza) from 18 months preintervention to 18 months afterward, adjusting each intervention's effects for co-occurring interventions and preintervention trends, with random effects for practices and clinicians.

RESULTS

There were 14,753 visits (mean patient age, 47 years; 69% women) for antibiotic-inappropriate acute respiratory tract infections during the baseline period and 16,959 visits (mean patient age, 48 years; 67% women) during the intervention period. Mean antibiotic prescribing rates decreased from 24.1% at intervention start to 13.1% at intervention month 18 (absolute difference, -11.0%) for control practices; from 22.1% to 6.1% (absolute difference, -16.0%) for suggested alternatives (difference in differences, -5.0% [95% CI, -7.8% to 0.1%]; P = .66 for differences in trajectories); from 23.2% to 5.2% (absolute difference, -18.1%) for accountable justification (difference in differences, -7.0% [95% CI, -9.1% to -2.9%]; P < .001); and from 19.9% to 3.7% (absolute difference, -16.3%) for peer comparison (difference in differences, -5.2% [95% CI, -6.9% to -1.6%]; P < .001). There were no statistically significant interactions (neither synergy nor interference) between interventions.

CONCLUSIONS AND RELEVANCE

Among primary care practices, the use of accountable justification and peer comparison as behavioral interventions resulted in lower rates of inappropriate antibiotic prescribing for acute respiratory tract infections.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01454947.

Use of Insurance Against a Small Loss as an Incentive Strategy

The success of extended warranties and buyer protection plans suggests that insurance against a small loss has high decision utility. We explore whether the behavioral insight that people are highly averse to small chances of loss can be used to create a powerful incentive that has very low expected value. We compare decisions of individuals offered fixed payments for healthy choices to those offered insurance in exchange for healthy choices. We test the prediction that aversion to small losses will result in very high rates of health behavior uptake in exchange for insurance. Three hundred participants endowed with a $2 bonus randomly received one of two incentives for completing a scheduled health risk assessment: (1) an insurance guarantee against the 1% risk of losing the $2 bonus or (2) a fixed payment at the expected value of the insurance. Relative to the fixed payment condition, participants in the insurance intervention were 70% more likely to meet their health risk assessment appointment (p < 0.01). Fixed payments of $2.59 were needed for every $1 spent on insurance to achieve the same behavioral effect. Loss aversion, probability weighting, and the certainty effect may account for this result. Incentive design may benefit from utilizing an insurance paradigm.

Factors associated with increased cesarean risk among African American women: evidence from California, 2010

OBJECTIVES

We studied if both observed and unobserved maternal health in African American women in hospitals or communities were associated with cesarean delivery of infants.

METHODS

We examined the relationship between African American race and cesarean delivery among 493 433 women discharged from 255 Californian hospitals in 2010 using administrative data; we adjusted for patient comorbidities and maternal, fetal, and placental risk factors, as well as clustering of patients within hospitals.

RESULTS

Cesarean rates were significantly higher overall for African American women than other women (unadjusted rate 36.8% vs 32.7%), as were both elective and emergency primary cesarean rates. Elevated risks persisted after risk adjustment (odds ratio generally > 1.27), but the prevalence of particular risk factors varied. Although African American women were clustered in some hospitals, the proportion of African Americans among all women delivering in a hospital was not related to its overall cesarean rate.

CONCLUSIONS

To address the higher likelihood of elective cesarean delivery, attention needs to be given to currently unmeasured patient-level health factors, to the quality of provider-physician interactions, as well as to patient preferences.

Nudging physician prescription decisions by partitioning the order set: results of a vignette-based study

BACKGROUND

Healthcare professionals are rapidly adopting electronic health records (EHRs). Within EHRs, seemingly innocuous menu design configurations can influence provider decisions for better or worse.

OBJECTIVE

The purpose of this study was to examine whether the grouping of menu items systematically affects prescribing practices among primary care providers.

PARTICIPANTS

We surveyed 166 primary care providers in a research network of practices in the greater Chicago area, of whom 84 responded (51% response rate). Respondents and non-respondents were similar on all observable dimensions except that respondents were more likely to work in an academic setting.

DESIGN

The questionnaire consisted of seven clinical vignettes. Each vignette described typical signs and symptoms for acute respiratory infections, and providers chose treatments from a menu of options. For each vignette, providers were randomly assigned to one of two menu partitions. For antibiotic-inappropriate vignettes, the treatment menu either listed over-the-counter (OTC) medications individually while grouping prescriptions together, or displayed the reverse partition. For antibiotic-appropriate vignettes, the treatment menu either listed narrow-spectrum antibiotics individually while grouping broad-spectrum antibiotics, or displayed the reverse partition.

MAIN MEASURES

The main outcome was provider treatment choice. For antibiotic-inappropriate vignettes, we categorized responses as prescription drugs or OTC-only options. For antibiotic-appropriate vignettes, we categorized responses as broad- or narrow-spectrum antibiotics.

KEY RESULTS

Across vignettes, there was an 11.5 percentage point reduction in choosing aggressive treatment options (e.g., broad-spectrum antibiotics) when aggressive options were grouped compared to when those same options were listed individually (95% CI: 2.9 to 20.1%; p = .008).

CONCLUSIONS

Provider treatment choice appears to be influenced by the grouping of menu options, suggesting that the layout of EHR order sets is not an arbitrary exercise. The careful crafting of EHR order sets can serve as an important opportunity to improve patient care without constraining physicians' ability to prescribe what they believe is best for their patients.

pSCANNER: patient-centered Scalable National Network for Effectiveness Research

This article describes the patient-centered Scalable National Network for Effectiveness Research (pSCANNER), which is part of the recently formed PCORnet, a national network composed of learning healthcare systems and patient-powered research networks funded by the Patient Centered Outcomes Research Institute (PCORI). It is designed to be a stakeholder-governed federated network that uses a distributed architecture to integrate data from three existing networks covering over 21 million patients in all 50 states: (1) VA Informatics and Computing Infrastructure (VINCI), with data from Veteran Health Administration's 151 inpatient and 909 ambulatory care and community-based outpatient clinics; (2) the University of California Research exchange (UC-ReX) network, with data from UC Davis, Irvine, Los Angeles, San Francisco, and San Diego; and (3) SCANNER, a consortium of UCSD, Tennessee VA, and three federally qualified health systems in the Los Angeles area supplemented with claims and health information exchange data, led by the University of Southern California. Initial use cases will focus on three conditions: (1) congestive heart failure; (2) Kawasaki disease; (3) obesity. Stakeholders, such as patients, clinicians, and health service researchers, will be engaged to prioritize research questions to be answered through the network. We will use a privacy-preserving distributed computation model with synchronous and asynchronous modes. The distributed system will be based on a common data model that allows the construction and evaluation of distributed multivariate models for a variety of statistical analyses.

Public hospital quality report awareness: evidence from National and Californian Internet searches and social media mentions, 2012

OBJECTIVES

Publicly available hospital quality reports seek to inform consumers of important healthcare quality and affordability attributes, and may inform consumer decision-making. To understand how much consumers search for such information online on one Internet search engine, whether they mention such information in social media and how positively they view this information.

SETTING AND DESIGN

A leading Internet search engine (Google) was the main focus of the study. Google Trends and Google Adwords keyword analyses were performed for national and Californian searches between 1 August 2012 and 31 July 2013 for keywords related to 'top hospital', best hospital', and 'hospital quality', as well as for six specific hospital quality reports. Separately, a proprietary social media monitoring tool was used to investigate blog, forum, social media and traditional media mentions of, and sentiment towards, major public reports of hospital quality in California in 2012.

PRIMARY OUTCOME MEASURES

(1) Counts of searches for keywords performed on Google; (2) counts of and (3) sentiment of mentions of public reports on social media.

RESULTS

National Google search volume for 75 hospital quality-related terms averaged 610 700 searches per month with strong variation by keyword and by state. A commercial report (Healthgrades) was more commonly searched for nationally on Google than the federal government's Hospital Compare, which otherwise dominated quality-related search terms. Social media references in California to quality reports were generally few, and commercially produced hospital quality reports were more widely mentioned than state (Office of Statewide Healthcare Planning and Development (OSHPD)), or non-profit (CalHospitalCompare) reports.

CONCLUSIONS

Consumers are somewhat aware of hospital quality based on Internet search activity and social media disclosures. Public stakeholders may be able to broaden their quality dissemination initiatives by advertising on Google or Twitter and using social media interactively with consumers looking for relevant information.

Cost-effectiveness of prolonged exposure therapy versus pharmacotherapy and treatment choice in posttraumatic stress disorder (the Optimizing PTSD Treatment Trial): a doubly randomized preference trial

OBJECTIVE

Cost-effectiveness of treatment for posttraumatic stress disorder (PTSD) may depend on type of treatment (eg, pharmacotherapy vs psychotherapy) and patient choice of treatment. We examined the cost-effectiveness of treatment with prolonged exposure therapy versus pharmacotherapy with sertraline, overall treatment preference, preference for choosing prolonged exposure therapy, and preference for choosing pharmacotherapy with sertraline from the US societal perspective.

METHOD

Two hundred patients aged 18 to 65 years with PTSD diagnosis based on DSM-IV criteria enrolled in a doubly randomized preference trial. Patients were randomized to receive their treatment of choice (n = 97) or to be randomly assigned treatment (n = 103). In the choice arm, patients chose either prolonged exposure therapy (n = 61) or pharmacotherapy with sertraline (n = 36). In the no-choice arm, patients were randomized to either prolonged exposure therapy (n = 48) or pharmacotherapy with sertraline (n = 55). The total costs, including direct medical costs, direct nonmedical costs, and indirect costs, were estimated in 2012 US dollars; and total quality-adjusted life-year (QALY) was assessed using the EuroQoL Questionnaire-5 dimensions (EQ-5D) instrument in a 12-month period. This study was conducted from July 2004 to January 2009.

RESULTS

Relative to pharmacotherapy with sertraline, prolonged exposure therapy was less costly (-$262; 95% CI, -$5,068 to $4,946) and produced more QALYs (0.056; 95% CI, 0.014 to 0.100) when treatment was assigned, with 93.2% probability of being cost-effective at $100,000/QALY. Independently, giving a choice of treatment also yielded lower cost (-$1,826; 95% CI, -$4,634 to $749) and more QALYs (0.010; 95% CI, -0.019 to 0.044) over no choice of treatment, with 87.0% probability of cost-effectiveness at $100,000/QALY.

CONCLUSIONS

Giving PTSD patients a choice of treatment appears to be cost-effective. When choice is not possible, prolonged exposure therapy may provide a cost-effective option over pharmacotherapy with sertraline.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00127673.

Nudging guideline-concordant antibiotic prescribing: a randomized clinical trial

IMPORTANCE

"Nudges" that influence decision making through subtle cognitive mechanisms have been shown to be highly effective in a wide range of applications, but there have been few experiments to improve clinical practice.

OBJECTIVE

To investigate the use of a behavioral "nudge" based on the principle of public commitment in encouraging the judicious use of antibiotics for acute respiratory infections (ARIs).

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial in 5 outpatient primary care clinics. A total of 954 adults had ARI visits during the study timeframe: 449 patients were treated by clinicians randomized to the posted commitment letter (335 in the baseline period, 114 in the intervention period); 505 patients were treated by clinicians randomized to standard practice control (384 baseline, 121 intervention).

INTERVENTIONS

The intervention consisted of displaying poster-sized commitment letters in examination rooms for 12 weeks. These letters, featuring clinician photographs and signatures, stated their commitment to avoid inappropriate antibiotic prescribing for ARIs.

MAIN OUTCOMES AND MEASURES

Antibiotic prescribing rates for antibiotic-inappropriate ARI diagnoses in baseline and intervention periods, adjusted for patient age, sex, and insurance status.

RESULTS

Baseline rates were 43.5% and 42.8% for control and poster, respectively. During the intervention period, inappropriate prescribing rates increased to 52.7% for controls but decreased to 33.7% in the posted commitment letter condition. Controlling for baseline prescribing rates, we found that the posted commitment letter resulted in a 19.7 absolute percentage reduction in inappropriate antibiotic prescribing rate relative to control (P = .02). There was no evidence of diagnostic coding shift, and rates of appropriate antibiotic prescriptions did not diminish over time.

CONCLUSIONS AND RELEVANCE

Displaying poster-sized commitment letters in examination rooms decreased inappropriate antibiotic prescribing for ARIs. The effect of this simple, low-cost intervention is comparable in magnitude to costlier, more intensive quality-improvement efforts.

TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT01767064.

Use of behavioral economics and social psychology to improve treatment of acute respiratory infections (BEARI): rationale and design of a cluster randomized controlled trial [1RC4AG039115-01]--study protocol and baseline practice and provider characteristics

BACKGROUND

Inappropriate antibiotic prescribing for nonbacterial infections leads to increases in the costs of care, antibiotic resistance among bacteria, and adverse drug events. Acute respiratory infections (ARIs) are the most common reason for inappropriate antibiotic use. Most prior efforts to decrease inappropriate antibiotic prescribing for ARIs (e.g., educational or informational interventions) have relied on the implicit assumption that clinicians inappropriately prescribe antibiotics because they are unaware of guideline recommendations for ARIs. If lack of guideline awareness is not the reason for inappropriate prescribing, educational interventions may have limited impact on prescribing rates. Instead, interventions that apply social psychological and behavioral economic principles may be more effective in deterring inappropriate antibiotic prescribing for ARIs by well-informed clinicians.

METHODS/DESIGN

The Application of Behavioral Economics to Improve the Treatment of Acute Respiratory Infections (BEARI) Trial is a multisite, cluster-randomized controlled trial with practice as the unit of randomization. The primary aim is to test the ability of three interventions based on behavioral economic principles to reduce the rate of inappropriate antibiotic prescribing for ARIs. We randomized practices in a 2 × 2 × 2 factorial design to receive up to three interventions for non-antibiotic-appropriate diagnoses: 1) Accountable Justifications: When prescribing an antibiotic for an ARI, clinicians are prompted to record an explicit justification that appears in the patient electronic health record; 2) Suggested Alternatives: Through computerized clinical decision support, clinicians prescribing an antibiotic for an ARI receive a list of non-antibiotic treatment choices (including prescription options) prior to completing the antibiotic prescription; and 3) Peer Comparison: Each provider's rate of inappropriate antibiotic prescribing relative to top-performing peers is reported back to the provider periodically by email. We enrolled 269 clinicians (practicing attending physicians or advanced practice nurses) in 49 participating clinic sites and collected baseline data. The primary outcome is the antibiotic prescribing rate for office visits with non-antibiotic-appropriate ARI diagnoses. Secondary outcomes will examine antibiotic prescribing more broadly. The 18-month intervention period will be followed by a one year follow-up period to measure persistence of effects after interventions cease.

DISCUSSION

The ongoing BEARI Trial will evaluate the effectiveness of behavioral economic strategies in reducing inappropriate prescribing of antibiotics.

TRIALS REGISTRATION

ClinicalTrials.gov: NCT01454947.

Minimal clinically important differences for the EQ-5D and QWB-SA in Post-traumatic Stress Disorder (PTSD): results from a Doubly Randomized Preference Trial (DRPT)

OBJECTIVE

To determine the minimal clinically important difference (MCID) for the health-utility measures EuroQol-5 dimensions (EQ-5D) and Quality of Well Being Self-Administered (QWB-SA) Scale in PTSD patients.

RESEARCH DESIGN AND METHODS

Two hundred patients aged 18 to 65 years with PTSD enrolled in a doubly randomized preference trial (DRPT) examining the treatment and treatment-preference effects between cognitive behavioral therapy and pharmacotherapy with sertraline and completed the EQ-5D and QWB-SA at baseline and 10-week post-treatment. The anchor-based methods utilized a Clinical Global Impression-Improvement (CGI-I) and Clinical Global Impression-Severity. We regressed the changes in EQ-5D and QWB-SA scores on changes in the anchors using ordinary least squares regression. The slopes (beta coefficients) were the rates of change in the anchors as functions of change in EQ-5D and QWB, which represent our estimates of MCID. In addition, we performed receiver operating characteristic (ROC) curve analysis to examine the relationship between the changes in EQ-5D and QWB-SA scores and treatment-response status. The MCIDs were estimated from the ROC curve where they best discriminate between treatment responders and non-responders. The distribution-based methods used small to moderate effect size in terms of 0.2 and 0.5 of standard deviation of the pre-treatment EQ-5D and QWB-SA scores.

RESULTS

The anchor-based methods estimated the MCID ranges of 0.05 to 0.08 for the EQ-5D and 0.03 to 0.05 for the QWB. The MCID ranges were higher with the distribution-based methods, ranging from 0.04 to 0.10 for the EQ-5D and 0.02 to 0.05 for the QWB-SA.

CONCLUSIONS

The established MCID ranges of EQ-5D and QWB-SA can be a useful tool in assessing meaningful changes in patient's quality of life for researchers and clinicians, and assisting health-policy makers to make informing decision in mental health treatment.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov; Identifier: NCT00127673.

Quality of life in haemophilia A: Hemophilia Utilization Group Study Va (HUGS-Va)

This study describes health-related quality of life (HRQoL) of persons with haemophilia A in the United States (US) and determines associations between self-reported joint pain, motion limitation and clinically evaluated joint range of motion (ROM), and between HRQoL and ROM. As part of a 2-year cohort study, we collected baseline HRQoL using the SF-12 (adults) and PedsQL (children), along with self-ratings of joint pain and motion limitation, in persons with factor VIII deficiency recruited from six Haemophilia Treatment Centres (HTCs) in geographically diverse regions of the US. Clinically measured joint ROM measurements were collected from medical charts of a subset of participants. Adults (N = 156, mean age: 33.5 ± 12.6 years) had mean physical and mental component scores of 43.4 ± 10.7 and 50.9 ± 10.1, respectively. Children (N = 164, mean age: 9.7 ± 4.5 years) had mean total PedsQL, physical functioning, and psychosocial health scores of 85.9 ± 13.8, 89.5 ± 15.2, and 84.1 ± 15.3, respectively. Persons with more severe haemophilia and higher self-reported joint pain and motion limitation had poorer scores, particularly in the physical aspects of HRQoL. In adults, significant correlations (P < 0.01) were found between ROM measures and both self-reported measures. Except among those with severe disease, children and adults with haemophilia have HRQoL scores comparable with those of the healthy US population. The physical aspects of HRQoL in both adults and children with haemophilia A in the US decrease with increasing severity of illness. However, scores for mental aspects of HRQoL do not differ between severity groups. These findings are comparable with those from studies in European and Canadian haemophilia populations.

Comparative effectiveness of statin plus fibrate combination therapy and statin monotherapy in patients with type 2 diabetes: use of propensity-score and instrumental variable methods to adjust for treatment-selection bias

PURPOSE

Type 2 diabetes is associated with increased cardiovascular risk. The comparative effectiveness of statin plus fibrate combination therapy and statin monotherapy in reducing risk of cardiovascular disease in real-world settings is unknown.

METHODS

A retrospective database analysis was performed using a large managed care claims database of patients identified with type 2 diabetes based on diagnosis codes from January 2002 through December 2003 and continuously enrolled for the entire study period, 5.5 years. A statin plus fibrate combination therapy group (patients who used statins less than 6 months and augmented with fibrates for more than 6 months) and a statin monotherapy group (patients who used statins persistently) among patients with type 2 diabetes were followed for 3 years to examine the relationship between the intervention and cardiovascular events using a multivariable logistic regression model, propensity score method, and instrumental variable approach.

RESULTS

The statin plus fibrate combination therapy group of 318 and the statin monotherapy group of 9928 were identified from 75,515 diabetics. After adjusting for factors that can impact cardiovascular outcomes, the combination therapy group did not significantly experience a reduction in cardiovascular disease, as compared with the statin monotherapy group (OR = 0.77; p = 0.083). The statin plus fibrate combination therapy group was significantly associated with a reduction in cardiovascular events after propensity matching (OR = 0.53; p = 0.002). Using the physician prescribing preference instrument to adjust for unmeasured confounding, we did not find evidence that subjects in the statin plus fibrate combination therapy group versus stain monotherapy group experienced a significant reduction in cardiovascular events (p = 0.124).

CONCLUSIONS

We did not find a difference in effectiveness regarding cardiovascular outcomes between the statin plus fibrate combination therapy and the statin monotherapy after controlling for hidden bias.

Applying the XForms Standard to Public Health Case Reporting and Alerting

Notifiable condition reporting and alerting are two important public health functions. Today, a variety of methods are used to transfer these types of information. The increasing use of electronic health record systems by healthcare providers makes new types of electronic communication possible. We used the XForms standard and nationally recognized technical profiles to demonstrate the communication of both notifiable condition reports and patient-tailored public health alerts. This demonstration of bi-directional communication took placein a prototypical health information exchange environment. We successfully transferred information between provider electronic health record systems and public health systems for notifiable condition reporting. Patient-specific alerts were successfully sent from public health to provider systems. In this paper we discuss the benefits of XForms, including the use of XML, advanced form controls, form initialization and reduction in scripting. We also review implementation challenges, the maturity of the technology and its suitability for use in public health.

How to Aggregate Health? Separability and the Effect of Framing

Background. Unweighted summation or quality-adjusted life year (QALY) utilitarianism is the most common way to aggregate health benefits in a cost-effectiveness analysis. A key qualitative principle underlying QALY utilitarianism is separability: those individuals unaffected by a policy choice should not influence the policy choice. Separability also underlies several of the alternatives for QALY utilitarianism that have been proposed. Objectives. To test separability and to test whether the support for separability is affected by the framing of the choice questions. Methods. In 2 experiments, 345 student subjects (162 in the first experiment, and 183 in the second experiment) were asked to select 1 of 2 possible treatments, with each treatment resulting in a different distribution of health across individuals. The only aspect that varied across choice questions was the state of the patients whose health was unaffected by the act of choosing a policy. In each experiment, we used 2 frames. In the implicit frame, it was implied but not plainly expressed what outcomes the treatments had in common. In the explicit frame, common outcomes of the 2 treatments were directly stated. The 2 experiments differed in the way the explicit frame was presented (verbal v. numerical). Results. The support for separability was significantly greater in the explicit frame. The proportion of violations in the implicit frame was 44% in Experiment 1 and 31% in Experiment 2, while in the explicit frame, the proportion of violations was 28% in Experiment 1 and 8% in Experiment 2. Conclusions. Framing affected the support for separability, raising issues as to whether it is possible to achieve a canonical representation of social choices.

Comparison of one and two-stage revision of total hip arthroplasty complicated by infection: a Markov expected-utility decision analysis

BACKGROUND

Two-stage revisions of total hip arthroplasties complicated by chronic infection result in reinfection rates that are lower than those following single-stage revisions but may also result in increased surgical morbidity. Using a decision analysis, we compared single-stage and two-stage revisions to determine which treatment modality resulted in greater quality-adjusted life years (QALYs).

METHODS

A review of the literature on the treatment of patients with an infection at the site of a total hip arthroplasty provided probabilities; utility values for common postoperative health states were determined in a previously published study. With these data, we conducted a Markov cohort simulation decision analysis. Sensitivity analysis validated the model, and comparisons were made in terms of QALYs.

RESULTS

The twelve-month model favored direct-exchange revision over the two-stage approach, regardless of whether surgeon or patient-derived utilities were used (0.945 versus 0.896 and 0.897 versus 0.861 QALYs for the patient and surgeon models, respectively). Similar results were observed in a lifetime model with a ten-year life expectancy (7.853 versus 7.771, and 7.438 versus 7.362 QALYs, respectively). The findings were found to be robust in sensitivity analyses in which clinically relevant ranges of input variables were used.

CONCLUSIONS

This analysis favored the direct-exchange arthroplasty over the two-stage approach. This study should be considered hypothesis-generating for future randomized controlled trials in which, ideally, health end points will be considered in addition to the eradication of infection.

Predictors of health-related quality-of-life utilities among persons with posttraumatic stress disorder

OBJECTIVES

This study had two objectives: to elicit preferences for current health in a sample of persons with posttraumatic stress disorder (PTSD ) in order to establish quality-of-life estimates for this disorder and to identify symptoms and problems that predict these estimates.

METHODS

The authors used the standard gamble (SG), time tradeoff (TTO), and visual analog scale (VAS) methods for quality-of-life estimation at baseline among 184 individuals with chronic PTSD who were participating in a multisite clinical trial. Descriptive statistics were used to characterize quality-of-life estimates for the sample. A linear mixed-effects regression model was conducted to evaluate predictors of quality of life.

RESULTS

The modal participant was a single, white female (77%). The mean ± SD age of the sample was 37.31 ± 11.33. On a scale where full health is 1.0 and death is 0.0, mean quality-of-life estimates for living with PTSD were .87 ±.25, .66 ± .28, and .64 ± .20 for SG, TTO, and VAS, respectively. Linear mixed-effects model regression revealed that elicitation method (SG, TTO, and VAS), arousal (a symptom of PTSD), and endorsement of anxiety or depressive symptoms were the strongest predictors of lower quality-of-life scores. Avoidance and re-experiencing of trauma were not predictive of reduced quality of life.

CONCLUSIONS

Significant decrements in health-related quality of life were found among persons seeking treatment for PTSD. Although arousal and anxiety and depressive symptoms were predictive of quality-of-life estimates, avoidance and re-experiencing were not. These findings identify targets for symptom resolution that may improve quality of life among persons with PTSD.

Detecting 'wrong blood in tube' errors: Evaluation of a Bayesian network approach

OBJECTIVE

In an effort to address the problem of laboratory errors, we develop and evaluate a method to detect mismatched specimens from nationally collected blood laboratory data in two experiments.

METHODS

In Experiments 1 and 2 using blood labs from National Health and Nutrition Examination Survey (NHANES) and values derived from the Diabetes Prevention Program (DPP) respectively, a proportion of glucose and HbA1c specimens were randomly mismatched. A Bayesian network that encoded probabilistic relationships among analytes was used to predict mismatches. In Experiment 1 the performance of the network was compared against existing error detection software. In Experiment 2 the network was compared against 11 human experts recruited from the American Academy of Clinical Chemists. Results were compared via area under the receiver-operator characteristic curves (AUCs) and with agreement statistics.

RESULTS

In Experiment 1 the network was most predictive of mismatches that produced clinically significant discrepancies between true and mismatched scores ((AUC of 0.87 (±0.04) for HbA1c and 0.83 (±0.02) for glucose), performed well in identifying errors among those self-reporting diabetes (N=329) (AUC=0.79 (±0.02)) and performed significantly better than the established approach it was tested against (in all cases p<.0.05). In Experiment 2 it performed better (and in no case worse) than 7 of the 11 human experts. Average percent agreement was 0.79 and Kappa (κ) was 0.59, between experts and the Bayesian network.

CONCLUSIONS

Bayesian network can accurately identify mismatched specimens. The algorithm is best at identifying mismatches that result in a clinically significant magnitude of error.

Detecting Blood Laboratory Errors Using a Bayesian Network

Objectives: To detect errors in blood laboratory results using a Bayesian network (BN), to compare results with an established method for detecting errors based on frequency patterns (LabRespond) and logistic regression model. Methods: In Experiment 1 and 2 using a sample of 5,800 observations from the National Health and Nutrition Examination Survey dataset, large, medium and small errors were randomly generated and introduced to liver enzymes (ALT, AST, and LDH) of the dataset. Experiment 1 examined systematic errors, while Experiment 2 investigated random errors. The outcome of interest was the correct detection of liver enzymes as “error” or “not error.” With the BN, the outcome was predicted by exploiting probabilistic relationships among AST, ALT, LDH, and gender. In addition to AST, ALT, LDH, and gender, LabRespond required more information on related analytes to achieve optimal prediction. We assessed performance by examining the area under the receiver operating characteristics curves using a 10-fold cross validation method, as well as risk stratification tables. Results: In Experiment 1, the BN significantly outperformed both LabRespond and logistic regression in detecting large (both at p < 0.001), medium ( p = 0.01 and p < 0.001, respectively), and small ( p = 0.03 and, p = 0.05, respectively) systematic errors. In Experiment 2, the BN performed significantly better than LabRespond and multinomial logistic regression in detecting large ( p = 0.04 and p < 0.001, respectively) and medium ( p = 0.05 and p < 0.001, respectively) random errors. Conclusion: A Bayesian network is better at detection and can detect errors with less information than existing automated models, suggesting that Bayesian model may be an effective means for reducing medical costs and improving patient safety.

When are person tradeoffs valid?

The person tradeoff (PTO) is commonly used in health economic applications. However, to date it has no theoretical basis. The purpose of this paper is to provide this basis from a set of assumptions that together justify the most common applications of the PTO method. Our analysis identifies the central assumptions in PTO measurements. We test these assumptions in an experiment, but find only limited support for the validity of the PTO.