Diagnosed Gonorrhea Among Privately Insured Women: Analysis of United States Claims Data.

Background: Gonorrhea incidence in the United States has risen by nearly 50% in the last decade, while screening rates have increased. Gonorrhea sequelae rates could indicate whether increased gonorrhea incidence is due to better screening. We estimated the association of gonorrhea diagnosis with pelvic inflammatory disease (PID), ectopic pregnancy (EP), and tubal factor infertility (TFI) in women and detected changes in associations over time. Materials and Methods: This retrospective cohort study included 5,553,506 women aged 18-49 tested for gonorrhea in the IBM MarketScan claims administrative database from 2013-2018 in the United States. We estimated incidence rates and hazard ratios (HRs) of gonorrhea diagnosis for each outcome, adjusting for potential confounders using Cox proportional hazards models. We tested the interaction between gonorrhea diagnosis and the initial gonorrhea test year to identify changes in associations over time. Results: We identified 32,729 women with a gonorrhea diagnosis (mean follow-up time in years: PID = 1.73, EP = 1.75, TFI = 1.76). A total of 131,500 women were diagnosed with PID, 64,225 had EP, and 41,507 had TFI. Women with gonorrhea diagnoses had greater incidence per 1000 person-years for all outcomes (PID = 33.5, EP = 9.4, TFI = 5.3) compared to women without gonorrhea diagnoses (PID = 13.9, EP = 6.7, TFI = 4.3). After adjustment, HRs were higher in women with a gonorrhea diagnosis vs. those without [PID = 2.29 (95% confidence interval, CI: 2.15-2.44), EP = 1.57, (95% CI: 1.41-1.76), TFI = 1.70 (95% CI: 1.47-1.97)]. The interaction of gonorrhea diagnosis and test year was not significant, indicating no change in relationship by initial test year. Conclusion: The relationship between gonorrhea and reproductive outcomes has persisted, suggesting a higher disease burden.

Barriers, opportunities, and potential costs of expanding HIV support services.

Experiencing housing instability, food insecurity, and financial stress can negatively impact retention in care and treatment adherence for people living with HIV. Expanding services that support socioeconomic needs could help improve HIV outcomes. Our objective was to investigate barriers, opportunities, and costs of expanding socioeconomic support programs. Semi-structured interviews were conducted with organizations serving U.S. Ryan White HIV/AIDS Program clients. Costs were estimated from interviews, organization documents, and city-specific wages. Organizations reported complex patient, organization, program, and system challenges as well as several opportunities for expansion. The average one-year per-person cost for engaging new clients was $196 for transportation, $612 for financial aid, $650 for food aid, and $2498 for short-term housing (2020 USD). Understanding potential expansion costs is important for funders and local stakeholders. This study provides a sense of magnitude for costs to scale-up programs to better meet socioeconomic needs of low-income patients living with HIV.

Evaluation of Strategies to Improve Uptake of Expedited Partner Therapy for Chlamydia trachomatis Treatment in Minnesota: A Decision Analytic Model.

Background. Despite the established effectiveness of expedited partner therapy (EPT) in partner treatment of bacterial sexually transmitted infections (STI), the practice is underutilized. Objective. To estimate the relative effectiveness of strategies to increase EPT uptake (numbers of partners treated for chlamydia). Methods. We developed a care cascade model of cumulative probabilities to estimate the number of partners treated under strategies to increase EPT uptake in Minnesota. The care cascade model used data from clinical trials, population-based studies, and Minnesota chlamydia surveillance as well as in-depth interviews of health providers who regularly treat STI patients and a statewide survey of health providers across Minnesota. Results. Several strategies could improve EPT uptake among providers, including facilitating treatment payment (additional 1,932 partners treated) and implementing electronic health record reminders (additional 1,755 partners treated). Addressing concerns about liability would have the greatest effect, resulting in 2,187 additional partners treated. Conclusions. Providers expressed openness to offering EPT under several scenarios, which reflect differences in knowledge about EPT, its legality, and potential risks to patients. While addressing concerns about provider liability would have the greatest effect on number of partners treated, provider education and procedural changes could make a substantial impact. Highlights: Addressing provider concerns about expedited partner therapy (EPT) legality and its potential risks would result in the most partners treated for chlamydia.EPT alerts and electronic EPT prescriptions may also streamline partner treatment.Provider education about the legality of EPT and its potential risks and training in counseling patients on EPT could also increase uptake.

Variation in local Ryan White HIV/AIDS program service use and impacts on viral suppression: informing quality improvement efforts.

The U.S. Ryan White HIV/AIDS Program (RWHAP) funds comprehensive services for people living with HIV to support viral suppression (VS). We analyzed five years of RWHAP data from the Minneapolis-St. Paul region to (1) assess variation and (2) evaluate the causal effect of each RWHAP service on sustained VS by race/ethnicity. Sixteen medical and support services were included. Descriptive analyses assessed service use and trends over time. Causal analyses used generalized estimating equations and propensity scores to adjust for the probability of service use. Receipt of AIDS Drug Assistance Program and financial aid consistently showed higher probabilities of sustained VS, while food aid and transportation aid had positive impacts on VS at higher levels of service encounters; however, the impact of services could vary by race/ethnicity. For example, financial aid increased the probability of sustained VS by at least 3 percentage points for white, Hispanic and Black/African American clients, but only 1.6 points for Black/African-born clients. This study found that services addressing socioeconomic needs typically had positive impacts on viral suppression, yet service use and impact of services often varied by race/ethnicity. This highlights a need to ensure these services are designed and delivered in ways that equitably serve all clients.

An Introductory Tutorial on Cohort State-Transition Models in R Using a Cost-Effectiveness Analysis Example.

Decision models can combine information from different sources to simulate the long-term consequences of alternative strategies in the presence of uncertainty. A cohort state-transition model (cSTM) is a decision model commonly used in medical decision making to simulate the transitions of a hypothetical cohort among various health states over time. This tutorial focuses on time-independent cSTM, in which transition probabilities among health states remain constant over time. We implement time-independent cSTM in R, an open-source mathematical and statistical programming language. We illustrate time-independent cSTMs using a previously published decision model, calculate costs and effectiveness outcomes, and conduct a cost-effectiveness analysis of multiple strategies, including a probabilistic sensitivity analysis. We provide open-source code in R to facilitate wider adoption. In a second, more advanced tutorial, we illustrate time-dependent cSTMs.

A Tutorial on Time-Dependent Cohort State-Transition Models in R Using a Cost-Effectiveness Analysis Example.

In an introductory tutorial, we illustrated building cohort state-transition models (cSTMs) in R, where the state transition probabilities were constant over time. However, in practice, many cSTMs require transitions, rewards, or both to vary over time (time dependent). This tutorial illustrates adding 2 types of time dependence using a previously published cost-effectiveness analysis of multiple strategies as an example. The first is simulation-time dependence, which allows for the transition probabilities to vary as a function of time as measured since the start of the simulation (e.g., varying probability of death as the cohort ages). The second is state-residence time dependence, allowing for history by tracking the time spent in any particular health state using tunnel states. We use these time-dependent cSTMs to conduct cost-effectiveness and probabilistic sensitivity analyses. We also obtain various epidemiological outcomes of interest from the outputs generated from the cSTM, such as survival probability and disease prevalence, often used for model calibration and validation. We present the mathematical notation first, followed by the R code to execute the calculations. The full R code is provided in a public code repository for broader implementation.

Optimal timing and effectiveness of COVID-19 outbreak responses in China: a modelling study.

BACKGROUND: In January 2020, an outbreak of atypical pneumonia caused by a novel coronavirus, SARS-CoV-2, was reported in Wuhan, China. On Jan 23, 2020, the Chinese government instituted mitigation strategies to control spread. Most modeling studies have focused on projecting epidemiological outcomes throughout the pandemic. However, the impact and optimal timing of different mitigation approaches have not been well-studied. METHODS: We developed a mathematical model reflecting SARS-CoV-2 transmission dynamics in an age-stratified population. The model simulates health and economic outcomes from Dec 1, 2019 through Mar 31, 2020 for cities including Wuhan, Chongqing, Beijing, and Shanghai in China. We considered differences in timing and duration of three mitigation strategies in the early phase of the epidemic: city-wide quarantine on Wuhan, travel history screening and isolation of travelers from Wuhan to other Chinese cities, and general social distancing. RESULTS: Our model estimated that implementing all three mitigation strategies one week earlier would have averted 35% of deaths in Wuhan (50% in other cities) with a 7% increase in economic impacts (16-18% in other cities). One week's delay in mitigation strategy initiation was estimated to decrease economic cost by the same amount, but with 35% more deaths in Wuhan and more than 80% more deaths in the other cities. Of the three mitigation approaches, infections and deaths increased most rapidly if initiation of social distancing was delayed. Furthermore, social distancing of working-age adults was most critical to reducing COVID-19 outcomes versus social distancing among children and/or the elderly. CONCLUSIONS: Optimizing the timing of epidemic mitigation strategies is paramount and involves weighing trade-offs between preventing infections and deaths and incurring immense economic impacts. City-wide quarantine was not as effective as city-wide social distancing due to its much higher daily cost than social distancing. Under typical economic evaluation standards, the optimal timing for the full set of control measures would have been much later than Jan 23, 2020 (status quo).

Cost-effectiveness of Fecal Microbiota Transplantation for First Recurrent Clostridioides difficile Infection.

BACKGROUND: Both the American College of Gastroenterology and the Infectious Diseases Society of America (IDSA)/Society for Healthcare Epidemiology of America 2021 Clostridioides difficile infection (CDI) guidelines recommend fecal microbiota transplantation (FMT) for persons with multiple recurrent CDI. Emerging data suggest that FMT may have high cure rates when used for first recurrent CDI. The aim of this study was to assess the cost-effectiveness of FMT for first recurrent CDI. METHODS: We developed a Markov model to simulate a cohort of patients presenting with initial CDI infection. The model estimated the costs, effectiveness, and cost-effectiveness of different CDI treatment regimens recommended in the 2021 IDSA guidelines, with the additional option of FMT for first recurrent CDI. The model includes stratification by the severity of initial infection, estimates of cure, recurrence, and mortality. Data sources were taken from IDSA guidelines and published literature on treatment outcomes. Outcome measures were quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs). RESULTS: When FMT is available for first recurrent CDI, the optimal cost-effective treatment strategy is fidaxomicin for initial nonsevere CDI, vancomycin for initial severe CDI, and FMT for first and subsequent recurrent CDI, with an ICER of $27 135/QALY. In probabilistic sensitivity analysis at a $100 000 cost-effectiveness threshold, FMT for first and subsequent CDI recurrence was cost-effective 90% of the time given parameter uncertainty. CONCLUSIONS: FMT is a cost-effective strategy for first recurrent CDI. Prospective evaluation of FMT for first recurrent CDI is warranted to determine the efficacy and risk of recurrence.

Occupational Segregation And Hypertension Inequity: The Implication Of The Inverse Hazard Law Among Healthcare Workers.

In the United States (US), Black-particularly Black female-healthcare workers are more likely to hold occupations with high job demand, low job control with limited support from supervisors or coworkers and are more vulnerable to job loss than their white counterparts. These work-related factors increase the risk of hypertension. This study examines the extent to which occupational segregation explains the persistent racial inequity in hypertension in the healthcare workforce and the potential health impact of workforce desegregation policies. We simulated a US healthcare workforce with four occupational classes: health diagnosing professionals (i.e., highest status), health treating professionals, healthcare technicians, and healthcare aides (i.e., lowest status). We simulated occupational segregation by allocating 25-year-old workers to occupational classes with the race- and gender-specific probabilities estimated from the American Community Survey data. Our model used occupational class attributes and workers' health behaviors to predict hypertension over a 40-year career. We tracked the hypertension prevalence and the Black-white prevalence gap among the simulated workers under the staus quo condition (occupational segregation) and the experimental conditions in which occupational segregation was eliminated. We found that the Black-white hypertension prevalence gap became approximately one percentage point smaller in the experimental than in the status quo conditions. These findings suggest that policies designed to desegregate the healthcare workforce may reduce racial health inequities in this population. Our microsimulation may be used in future research to compare various desegregation policies as they may affect workers' health differently. Supplementary Information: The online version contains supplementary material available at 10.1007/s41996-022-00098-5.

Cost-Effectiveness of HIV Retention and Re-engagement Interventions in High-Income Countries: A Systematic Literature Review.

Engagement in lifelong HIV care is critical for both patient and public health, yet there are limited resources to invest in improving HIV outcomes. We systematically reviewed evidence on the cost-effectiveness of retention and re-engagement interventions. We searched five databases for peer-reviewed studies published between 2010 and 2020. We assessed reporting and methods quality, extracted data on target populations, interventions, and cost-effectiveness, and evaluated overall strength of evidence. Eleven studies met inclusion criteria, and eight had moderate-high quality. Cost-effectiveness estimates ranged from cost-saving to over $1,000,000/quality-adjusted life year (QALY) gained. Of the 73 cost-effectiveness ratios reported, 64% were < $100,000/QALY gained. Interventions were more likely to be cost-effective when targeted to high-risk groups, implemented in locations where baseline retention levels were low, and when used in combination with other high-impact HIV interventions (such as prevention). Overall, existing evidence is moderately strong that retention and/or re-engagement interventions can be cost-effective in high-income countries.

Cost-Effectiveness of Interventions to Improve HIV Pre-exposure Prophylaxis Initiation, Adherence, and Persistence Among Men Who Have Sex With Men.

BACKGROUND: To help achieve Ending the HIV Epidemic (EHE) goals of reducing new HIV incidence, pre-exposure prophylaxis (PrEP) use and engagement must increase despite multidimensional barriers to scale-up and limitations in funding. We investigated the cost-effectiveness of interventions spanning the PrEP continuum of care. SETTING: Men who have sex with men in Atlanta, GA, a focal jurisdiction for the EHE plan. METHODS: Using a network-based HIV transmission model, we simulated lifetime costs, quality-adjusted life years (QALYs), and infections averted for 8 intervention strategies using a health sector perspective. Strategies included a status quo (no interventions), 3 distinct interventions (targeting PrEP initiation, adherence, or persistence), and all possible intervention combinations. Cost-effectiveness was evaluated incrementally using a $100,000/QALY gained threshold. We performed sensitivity analyses on PrEP costs, intervention costs, and intervention coverage. RESULTS: Strategies averted 0.2%-4.2% new infections and gained 0.0045%-0.24% QALYs compared with the status quo. Initiation strategies achieved 20%-23% PrEP coverage (up from 15% with no interventions) and moderate clinical benefits at a high cost, while adherence strategies were relatively low cost and low benefit. Under our assumptions, the adherence and initiation combination strategy was cost-effective ($86,927/QALY gained). Sensitivity analyses showed no strategies were cost-effective when intervention costs increased by 60% and the strategy combining all 3 interventions was cost-effective when PrEP costs decreased to $1000/month. CONCLUSION: PrEP initiation interventions achieved moderate public health gains and could be cost-effective. However, substantial financial resources would be needed to improve the PrEP care continuum toward meeting EHE goals.

Addressing Pediatric HIV Pretreatment Drug Resistance and Virologic Failure in Sub-Saharan Africa: A Cost-Effectiveness Analysis of Diagnostic-Based Strategies in Children ≥3 Years Old.

Improvement of antiretroviral therapy (ART) regimen switching practices and implementation of pretreatment drug resistance (PDR) testing are two potential approaches to improve health outcomes for children living with HIV. We developed a microsimulation model of disease progression and treatment focused on children with perinatally acquired HIV in sub-Saharan Africa who initiate ART at 3 years of age. We evaluated the cost-effectiveness of diagnostic-based strategies (improved switching and PDR testing), over a 10-year time horizon, in settings without and with pediatric dolutegravir (DTG) availability as first-line ART. The improved switching strategy increases the probability of switching to second-line ART when virologic failure is diagnosed through viral load testing. The PDR testing strategy involves a one-time PDR test prior to ART initiation to guide choice of initial regimen. When DTG is not available, PDR testing is dominated by the improved switching strategy, which has an incremental cost-effectiveness ratio (ICER) of USD 579/life-year gained (LY), relative to the status quo. If DTG is available, improved switching has a similar ICER (USD 591/LY) relative to the DTGstatus quo. Even when substantial financial investment is needed to achieve improved regimen switching practices, the improved switching strategy still has the potential to be cost-effective in a wide range of sub-Saharan African countries. Our analysis highlights the importance of strengthening existing laboratory monitoring systems to improve the health of children living with HIV.

Cost-effectiveness analysis of pre-ART HIV drug resistance testing in Kenyan women.

BACKGROUND: The prevalence of pre-treatment drug resistance (PDR) to non-nucleoside reverse-transcriptase inhibitor (NNRTI) agents is increasing in sub-Saharan Africa, which may decrease the effectiveness of efavirenz-based antiretroviral therapy (ART) programs. However, due to recent safety concerns, there has been hesitancy to replace efavirenz-based ART with dolutegravir in women of reproductive potential. Our objective was to evaluate whether PDR testing for women not initiating dolutegravir-based ART would be a cost-effective strategy to address the challenges posed by PDR. METHODS: We developed an HIV drug resistance model that simulates the emergence and transmission of resistance mutations, calibrated to the Kenyan epidemic. We modeled three care strategies for PDR testing among women not initiating dolutegravir-based ART: no PDR testing, PDR testing with a low-cost point mutation assay, known as oligonucleotide ligation assay (OLA), and PDR testing with consensus sequencing. Using a health sector perspective, this model was used to evaluate the health outcomes, lifetime costs, and cost-effectiveness under each strategy over a 15-year time horizon starting in 2019. FINDINGS: OLA and CS PDR testing were projected to have incremental cost-effectiveness ratios (ICER) of $10,741/QALY gained and $134,396/QALY gained, respectively, which are not cost-effective by national income standards. Viral suppression rates among women at 12 months after ART initiation were 87·8%, 89·0%, and 89·3% with no testing, OLA testing, and CS testing, respectively. PDR testing with OLA and CS were associated with a 0.5% and 0.6% reduction in incidence rate compared to no PDR testing. Initial PDR prevalence among women was 13.1% in 2019. By 2034, this prevalence was 17·6%, 17·4%, and 17·3% with no testing, OLA testing, and CS testing, respectively. INTERPRETATION: PDR testing for women is unlikely to be cost-effective in Kenya whether one uses a low-cost assay, such as OLA, or consensus sequencing. FUNDING: National Institutes of Health, Gilead Sciences.

A Multidimensional Array Representation of State-Transition Model Dynamics.

Cost-effectiveness analyses often rely on cohort state-transition models (cSTMs). The cohort trace is the primary outcome of cSTMs, which captures the proportion of the cohort in each health state over time (state occupancy). However, the cohort trace is an aggregated measure that does not capture information about the specific transitions among health states (transition dynamics). In practice, these transition dynamics are crucial in many applications, such as incorporating transition rewards or computing various epidemiological outcomes that could be used for model calibration and validation (e.g., disease incidence and lifetime risk). In this article, we propose an alternative approach to compute and store cSTMs outcomes that capture both state occupancy and transition dynamics. This approach produces a multidimensional array from which both the state occupancy and the transition dynamics can be recovered. We highlight the advantages of the multidimensional array over the traditional cohort trace and provide potential applications of the proposed approach with an example coded in R to facilitate the implementation of our method.

Follow the Sex: Influence of Network Structure on the Effectiveness and Cost-Effectiveness of Partner Management Strategies for Sexually Transmitted Infection Control.

BACKGROUND: It is well established that network structure strongly influences infectious disease dynamics. However, little is known about how the network structure impacts the cost-effectiveness of disease control strategies. We evaluated partner management strategies to address bacterial sexually transmitted infections (STIs) as a case study to explore the influence of the network structure on the optimal disease management strategy. METHODS: We simulated a hypothetical bacterial STI spread through 4 representative network structures: random, community-structured, scale-free, and empirical. We simulated disease outcomes (prevalence, incidence, total infected person-months) and cost-effectiveness of 4 partner management strategies in each network structure: routine STI screening alone (no partner management), partner notification, expedited partner therapy, and contact tracing. We determined the optimal partner management strategy following a cost-effectiveness framework and varied key compliance parameters of partner management in sensitivity analysis. RESULTS: For the same average number of contacts and disease parameters in our setting, community-structured networks had the lowest incidence, prevalence, and total infected person-months, whereas scale-free networks had the highest without partner management. The highly connected individuals were more likely to be reinfected in scale-free networks than in the other network structures. The cost-effective partner management strategy depended on the network structures, the compliance in partner management, the willingness-to-pay threshold, and the rate of external force of infection. CONCLUSIONS: Our findings suggest that contact network structure matters in determining the optimal disease control strategy in infectious diseases. Information on a population's contact network structure may be valuable for informing optimal investment of limited resources.

Cost-effectiveness of Treatment Regimens for Clostridioides difficile Infection: An Evaluation of the 2018 Infectious Diseases Society of America Guidelines.

BACKGROUND: In 2018, the Infectious Diseases Society of America (IDSA) published guidelines for diagnosis and treatment of Clostridioides (formerly Clostridium) difficile infection (CDI). However, there is little guidance regarding which treatments are cost-effective. METHODS: We used a Markov model to simulate a cohort of patients presenting with an initial CDI diagnosis. We used the model to estimate the costs, effectiveness, and cost-effectiveness of different CDI treatment regimens recommended in the recently published 2018 IDSA guidelines. The model includes stratification by the severity of the initial infection, and subsequent likelihood of cure, recurrence, mortality, and outcomes of subsequent recurrences. Data sources were taken from IDSA guidelines and published literature on treatment outcomes. Outcome measures were discounted quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs). RESULTS: Use of fidaxomicin for nonsevere initial CDI, vancomycin for severe CDI, fidaxomicin for first recurrence, and fecal microbiota transplantation (FMT) for subsequent recurrence (strategy 44) cost an additional $478 for 0.009 QALYs gained per CDI patient, resulting in an ICER of $31 751 per QALY, below the willingness-to-pay threshold of $100 000/QALY. This is the optimal, cost-effective CDI treatment strategy. CONCLUSIONS: Metronidazole is suboptimal for nonsevere CDI as it is less beneficial than alternative strategies. The preferred treatment regimen is fidaxomicin for nonsevere CDI, vancomycin for severe CDI, fidaxomicin for first recurrence, and FMT for subsequent recurrence. The most effective treatments, with highest cure rates, are also cost-effective due to averted mortality, utility loss, and costs of rehospitalization and/or further treatments for recurrent CDI.

Proactive Vs Reactive Therapeutic Drug Monitoring of Infliximab in Crohn's Disease: A Cost-Effectiveness Analysis in a Simulated Cohort.

BACKGROUND: Therapeutic drug monitoring (TDM) is increasingly performed for Infliximab (IFX) in patients with Crohn's disease (CD). Reactive TDM is a cost-effective strategy to empiric IFX dose escalation. The cost-effectiveness of proactive TDM is unknown. The aim of this study is to assess the cost-effectiveness of proactive vs reactive TDM in a simulated population of CD patients on IFX. METHODS: We developed a stochastic simulation model of CD patients on IFX and evaluated the expected health costs and outcomes of a proactive TDM strategy compared with a reactive strategy. The proactive strategy measured IFX concentration and antibody status every 6 months, or at the time of a flare, and dosed IFX to a therapeutic window. The reactive strategy only did so at the time of a flare. RESULTS: The proactive strategy led to fewer flares than the reactive strategy. More patients stayed on IFX in the proactive vs reactive strategy (63.4% vs 58.8% at year 5). From a health sector perspective, a proactive strategy was marginally cost-effective compared with a reactive strategy (incremental cost-effectiveness ratio of $146,494 per quality-adjusted life year), assuming a 40% of the wholesale price of IFX. The results were most sensitive to risk of flaring with a low IFX concentration and the cost of IFX. CONCLUSIONS: Assuming 40% of the average wholesale acquisition cost of biologic therapies, proactive TDM for IFX is marginally cost-effective compared with a reactive TDM strategy. As the cost of infliximab decreases, a proactive monitoring strategy is more cost-effective.

A Need for Change! A Coding Framework for Improving Transparency in Decision Modeling.

The use of open-source programming languages, such as R, in health decision sciences is growing and has the potential to facilitate model transparency, reproducibility, and shareability. However, realizing this potential can be challenging. Models are complex and primarily built to answer a research question, with model sharing and transparency relegated to being secondary goals. Consequently, code is often neither well documented nor systematically organized in a comprehensible and shareable approach. Moreover, many decision modelers are not formally trained in computer programming and may lack good coding practices, further compounding the problem of model transparency. To address these challenges, we propose a high-level framework for model-based decision and cost-effectiveness analyses (CEA) in R. The proposed framework consists of a conceptual, modular structure and coding recommendations for the implementation of model-based decision analyses in R. This framework defines a set of common decision model elements divided into five components: (1) model inputs, (2) decision model implementation, (3) model calibration, (4) model validation, and (5) analysis. The first four components form the model development phase. The analysis component is the application of the fully developed decision model to answer the policy or the research question of interest, assess decision uncertainty, and/or to determine the value of future research through value of information (VOI) analysis. In this framework, we also make recommendations for good coding practices specific to decision modeling, such as file organization and variable naming conventions. We showcase the framework through a fully functional, testbed decision model, which is hosted on GitHub for free download and easy adaptation to other applications. The use of this framework in decision modeling will improve code readability and model sharing, paving the way to an ideal, open-source world.

"Time Traveling Is Just Too Dangerous" but Some Methods Are Worth Revisiting: The Advantages of Expected Loss Curves Over Cost-Effectiveness Acceptability Curves and Frontier.

BACKGROUND: Cost-effectiveness acceptability curves (CEACs) and the cost-effectiveness acceptability frontier (CEAF) are the recommended graphical representations of uncertainty in a cost-effectiveness analysis (CEA). Nevertheless, many limitations of CEACs and the CEAF have been recognized by others. Expected loss curves (ELCs) overcome these limitations by displaying the expected foregone benefits of choosing one strategy over others, the optimal strategy in expectation, and the value of potential future research all in a single figure. OBJECTIVES: To revisit ELCs, illustrate their benefits using a case study, and promote their adoption by providing open-source code. METHODS: We used a probabilistic sensitivity analysis of a CEA comparing 6 cerebrospinal fluid biomarker test-and-treat strategies in patients with mild cognitive impairment. We showed how to calculate ELCs for a set of decision alternatives. We used the probabilistic sensitivity analysis of the case study to illustrate the limitations of currently recommended methods for communicating uncertainty and then demonstrated how ELCs can address these issues. RESULTS: ELCs combine the probability that each strategy is not cost-effective on the basis of current information and the expected foregone benefits resulting from choosing that strategy (ie, how much is lost if we recommended a strategy with a higher expected loss). ELCs display how the optimal strategy switches across willingness-to-pay thresholds and enables comparison between different strategies in terms of the expected loss. CONCLUSIONS: ELCs provide a more comprehensive representation of uncertainty and overcome current limitations of CEACs and the CEAF. Communication of uncertainty in CEA would benefit from greater adoption of ELCs as a complementary method to CEACs, the CEAF, and the expected value of perfect information.

HIV Care Trajectories as a Novel Longitudinal Assessment of Retention in Care.

Consistent engagement in care is associated with positive health outcomes among people living with HIV (PLWH). However, traditional retention measures ignore the evolving dynamics of engagement in care. To understand the longitudinal patterns of HIV care, we analyzed medical records from 2008 to 2015 of PLWH ≥ 18 years-old receiving care at a public, hospital-based HIV clinic (N = 2110). Using latent class analysis, we identified five distinct care trajectory classes: (1) consistent care (N = 1281); (2) less frequent care (N = 270); (3) return to care after initial attrition (N = 192); (4) moderate attrition (N = 163); and (5) rapid attrition (N = 204). The majority of PLWH in Class 1 (73.9%) had achieved sustained viral suppression (viral load ≤ 200 copies/mL at last test and > 12 months prior) by study end. Among the other care classes, there was substantial variation in sustained viral suppression (61.1% in Class 2 to 3.4% in Class 5). Care trajectories could be used to prioritize re-engagement efforts.