Modelling small block aperture in an in-house developed GPU-accelerated Monte Carlo-based dose engine for pencil beam scanning proton therapy.

Purpose. To enhance an in-house graphic-processing-unit accelerated virtual particle (VP)-based Monte Carlo (MC) proton dose engine (VPMC) to model aperture blocks in both dose calculation and optimization for pencil beam scanning proton therapy (PBSPT)-based stereotactic radiosurgery (SRS).Methods and materials. A module to simulate VPs passing through patient-specific aperture blocks was developed and integrated in VPMC based on simulation results of realistic particles (primary protons and their secondaries). To validate the aperture block module, VPMC was first validated by an opensource MC code, MCsquare, in eight water phantom simulations with 3 cm thick brass apertures: four were with aperture openings of 1, 2, 3, and 4 cm without a range shifter, while the other four were with same aperture opening configurations with a range shifter of 45 mm water equivalent thickness. Then, VPMC was benchmarked with MCsquare and RayStation MC for 10 patients with small targets (average volume 8.4 c.c. with range of 0.4-43.3 c.c.). Finally, 3 typical patients were selected for robust optimization with aperture blocks using VPMC.Results. In the water phantoms, 3D gamma passing rate (2%/2 mm/10%) between VPMC and MCsquare was 99.71 ± 0.23%. In the patient geometries, 3D gamma passing rates (3%/2 mm/10%) between VPMC/MCsquare and RayStation MC were 97.79 ± 2.21%/97.78 ± 1.97%, respectively. Meanwhile, the calculation time was drastically decreased from 112.45 ± 114.08 s (MCsquare) to 8.20 ± 6.42 s (VPMC) with the same statistical uncertainties of ~0.5%. The robustly optimized plans met all the dose-volume-constraints (DVCs) for the targets and OARs per our institutional protocols. The mean calculation time for 13 influence matrices in robust optimization by VPMC was 41.6 s and the subsequent on-the-fly 'trial-and-error' optimization procedure took only 71.4 s on average for the selected three patients.Conclusion. VPMC has been successfully enhanced to model aperture blocks in dose calculation and optimization for the PBSPT-based SRS.

Modelling small block aperture in an in-house developed GPU-accelerated Monte Carlo-based dose engine for pencil beam scanning proton therapy.

Purpose: To enhance an in-house graphic-processing-unit (GPU) accelerated virtual particle (VP)-based Monte Carlo (MC) proton dose engine (VPMC) to model aperture blocks in both dose calculation and optimization for pencil beam scanning proton therapy (PBSPT)-based stereotactic radiosurgery (SRS). Methods and Materials: A module to simulate VPs passing through patient-specific aperture blocks was developed and integrated in VPMC based on simulation results of realistic particles (primary protons and their secondaries). To validate the aperture block module, VPMC was first validated by an opensource MC code, MCsquare, in eight water phantom simulations with 3cm thick brass apertures: four were with aperture openings of 1, 2, 3, and 4cm without a range shifter, while the other four were with same aperture opening configurations with a range shifter of 45mm water equivalent thickness. Then, VPMC was benchmarked with MCsquare and RayStation MC for 10 patients with small targets (average volume 8.4 cc with range of 0.4 - 43.3 cc). Finally, 3 typical patients were selected for robust optimization with aperture blocks using VPMC. Results: In the water phantoms, 3D gamma passing rate (2%/2mm/10%) between VPMC and MCsquare was 99.71±0.23%. In the patient geometries, 3D gamma passing rates (3%/2mm/10%) between VPMC/MCsquare and RayStation MC were 97.79±2.21%/97.78±1.97%, respectively. Meanwhile, the calculation time was drastically decreased from 112.45±114.08 seconds (MCsquare) to 8.20±6.42 seconds (VPMC) with the same statistical uncertainties of ~0.5%. The robustly optimized plans met all the dose-volume-constraints (DVCs) for the targets and OARs per our institutional protocols. The mean calculation time for 13 influence matrices in robust optimization by VPMC was 41.6 seconds and the subsequent on-the-fly "trial-and-error" optimization procedure took only 71.4 seconds on average for the selected three patients. Conclusion: VPMC has been successfully enhanced to model aperture blocks in dose calculation and optimization for the PBSPT-based SRS.

Healthcare costs and outcomes associated with laboratory-confirmed Lyme disease in Ontario, Canada: A population-based cohort study.

BACKGROUND: The objective of this study was to estimate the economic burden attributable to laboratory-confirmed Lyme disease (LD) in Ontario, Canada and assess health outcomes associated with LD. METHOD: We conducted a cohort study using laboratory-confirmed LD cases accrued between 2006 and 2018. The exposed cohort was matched 1:3 to the unexposed cohort using a combination of hard and propensity score matching. We used phase-of-care costing methods to calculate attributable costs for four phases of illness: pre-diagnosis, acute care, post-acute care, and continuing care in 2018 Canadian dollars. We used ICD-10-CA and OHIP billing codes to identify emergency department visits, physician billings and hospitalizations related to LD sequelae to assess health outcomes. RESULTS: A total of 2,808 cases were identified with a mean age of 46.5 (20.7) years and 44% female. Within 30-days, 404 (14.3%) cases required an ED visit and 63 (2.4%) cases required hospitalization. The mean (95% CI) total costs for LD cases in pre-diagnosis, acute, and post-acute care phases were $209 ($181, 238), $1,084 ($956, $1,212), and $1,714 ($1,499, $1,927), respectively. The highest mean attributable 10-day cost was $275 ($231, $319) during acute care. At 1-year post-infection, LD increased the relative risk of nerve palsies by 62 (20, 197), and polyneuropathy by 24 (3.0, 190). LD resulted in 16 Lyme meningitis events vs. 0 events in the unexposed. CONCLUSION: Individuals with laboratory-confirmed LD have increased healthcare resource use pre-diagnosis and up to six months post-diagnosis, and were more likely to seek healthcare services related to LD sequelae.

Renin-Angiotensin Inhibition and Outcomes in HFrEF and Advanced Kidney Disease.

BACKGROUND: Renin-angiotensin system inhibitors improve outcomes in patients with heart failure with reduced ejection fraction (HFrEF). However, less is known about their effectiveness in patients with HFrEF and advanced kidney disease. METHODS: In the Medicare-linked Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure (OPTIMIZE-HF), 1582 patients with HFrEF (ejection fraction ≤40%) had advanced kidney disease (estimated glomerular filtration rate <30 mL/min/1.73 m2). Of these, 829 were not receiving angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) prior to admission, of whom 214 were initiated on these drugs prior to discharge. We calculated propensity scores for receipt of these drugs for each of the 829 patients and assembled a matched cohort of 388 patients, balanced on 47 baseline characteristics (mean age 78 years; 52% women; 10% African American; 73% receiving beta-blockers). Hazard ratios (HR) and 95% confidence intervals (CI) were estimated comparing 2-year outcomes in 194 patients initiated on ACE inhibitors or ARBs to 194 patients not initiated on those drugs. RESULTS: The combined endpoint of heart failure readmission or all-cause mortality occurred in 79% and 84% of patients initiated and not initiated on ACE inhibitors or ARBs, respectively (HR associated with initiation, 0.79; 95% CI, 0.63-0.98). Respective HRs (95% CI) for the individual endpoints of - Respective HRs (95% CI) for the individual endpoints of all-cause mortality and heart failure readmission were 0.81 (0.63-1.03) and 0.63 (0.47-0.85). CONCLUSIONS: The findings from our study add new information to the body of cumulative evidence that suggest that renin-angiotensin system inhibitors may improve clinical outcomes in patients with HFrEF and advanced kidney disease. These hypothesis-generating findings need to be replicated in contemporary patients.

Patient Accessibility to Eye Care in the United States.

PURPOSE: The United States (US) federal government uses health provider shortage areas (HPSAs) to define patient accessibility to primary care physicians. It is unclear whether HPSAs can be applied to eye care providers (ECPs). Our study determined the applicability of federal HPSA designations to ECP availability in the US. DESIGN: Cross-sectional study. PARTICIPANTS: US general population and ophthalmologists/optometrists in the Medicare database. METHODS: The primary care HPSA score, visual impairment prevalence, and ECP location were determined for each census tract or county using data from the US Department of Health and Human Services, the Centers for Disease Control and Prevention, and Centers for Medicare and Medicaid Services. MAIN OUTCOME MEASURES: Association of HPSA with vision loss and ECP density was examined. The 2-step floating catchment area approach was used to newly define eye care shortage areas (patient accessibility score [PAS], higher being worse accessibility) for every county in the US, by weighting the 2-step FCA scores by prevalence of vision loss and ECP density. Multivariable logistic regression was used to identify sociodemographic variables associated with areas of ECP shortage. RESULTS: Among 72 735 census tracts included, statistically significant but weak correlations of HPSA score with visual impairment (VI) (r = 0.38; P < 0.0001) and ECP density per county population (r = -0.18; P < 0.0001) were found. Only 54.0% of census tracts with < 25th percentile ECP density per county were HPSAs (P < 0.0001). Of census tracts > than 75th percentile for VI only 58.0% were HPSAs (P < 0.0001). Multivariable regression found a higher odds of ECP PAS ≥ 75th percentile (worse accessibility) in rural counties (adjusted odds ratio [aOR], 2.47; 95% confidence interval [CI], 1.93-3.67; P < 0.001) and counties with a greater prevalence of residents with less than a high school education (aOR, 1.21; 95% CI, 1.19-1.25; P < 0.001), residents ≥ 65 years of age (aOR, 1.10; 95% CI, 1.07-1.13; P < 0.001), and uninsured residents (aOR, 1.04; 95% CI, 1.01-1.06; P < 0.001). Counties with a greater proportion of men (aOR, 0.93; 95% CI, 0.89-0.967; P < 0.001) or White residents (aOR, 0.99; 95% CI, 0.98-0.99) had a lower odds of ECP PAS ≥ 75th percentile. CONCLUSIONS: Current HPSAs only weakly correlate with ECP supply. We propose a new approach to identify counties with high need but limited access to eye care. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Gout incidence and management during the COVID-19 pandemic in England, UK: a nationwide observational study using OpenSAFELY.

BACKGROUND: Gout is the most prevalent inflammatory arthritis, yet one of the worst managed. Our objective was to assess how the COVID-19 pandemic impacted incidence and quality of care for people with gout in England, UK. METHODS: With the approval of National Health Service England, we did a population-level cohort study using primary care and hospital electronic health record data for 17·9 million adults registered with general practices using TPP health record software, via the OpenSAFELY platform. The study period was from March 1, 2015, to Feb 28, 2023. Individuals aged 18-110 years were defined as having incident gout if they were assigned index diagnostic codes for gout, were registered with TPP practices in England for at least 12 months before diagnosis, did not receive prescriptions for urate-lowering therapy more than 30 days before diagnosis, and had not been admitted to hospital or attended an emergency department for gout flares more than 30 days before diagnosis. Outcomes assessed were incidence and prevalence of people with recorded gout diagnoses, incidence of gout hospitalisations, initiation of urate-lowering therapy, and attainment of serum urate targets (≤360 µmol/L). FINDINGS: From a reference population of 17 865 145 adults, 246 695 individuals were diagnosed with incident gout. The mean age of individuals with incident gout was 61·3 years (SD 16·2). 66 265 (26·9%) of 246 695 individuals were female, 180 430 (73·1%) were male, and 189 035 (90·9%) of 208 050 individuals with available ethnicity data were White. Incident gout diagnoses decreased by 30·9% in the year beginning March, 2020, compared with the preceding year (1·23 diagnoses vs 1·78 diagnoses per 1000 adults). Gout prevalence was 3·07% in 2015-16, and 3·21% in 2022-23. Gout hospitalisations decreased by 30·1% in the year commencing March, 2020, compared with the preceding year (9·6 admissions vs 13·7 admissions per 100 000 adults). Of 228 095 people with incident gout and available follow-up, 66 560 (29·2%) were prescribed urate-lowering therapy within 6 months. Of 65 305 individuals who initiated urate-lowering therapy with available follow-up, 16 790 (25·7%) attained a serum urate concentration of 360 µmol/L or less within 6 months of urate-lowering therapy initiation. In interrupted time-series analyses, urate-lowering therapy prescribing improved modestly during the pandemic, compared with pre-pandemic, whereas urate target attainment was similar. INTERPRETATION: Using gout as an exemplar disease, we showed the complexity of how health care was impacted during the COVID-19 pandemic. We observed a reduction in gout diagnoses but no effect on treatment metrics. We showed how country-wide, routinely collected data can be used to map disease epidemiology and monitor care quality. FUNDING: None.

Pan-Canadian consensus recommendations for proton beam therapy access in Canada.

PURPOSE: Proton Beam Therapy (PBT)is a treatment option for select cancer patients. It is currently not available in Canada. Assessment and referral processes for out-of-country treatment for eligible patients vary by jurisdiction, leading to variability in access to this treatment for Canadian cancer patients. The purpose of this initiative was to develop a framework document to inform consistent and equitable PBT access for appropriate patients through the creation of pan-Canadian PBT access consensus recommendations. MATERIALS AND METHODS: A modified Delphiprocess was used to develop pan-Canadian recommendations with input from 22 PBT clinical and administrative experts across all provinces, external peer-review by provincial cancer and system partners, and feedback from a targeted community consultation. This was conducted by electronic survey and live discussion. Consensus threshold was set at 70% agreement. RESULTS: Fourconsensus rounds resulted in a final set of 27 recommendations divided into three categories: patient eligibility (n = 9); program level (n = 10); and system level (n = 8). Patient eligibility included: anatomic site (n = 4), patient characteristics (n = 3), clinical efficacy (n = 2). Program level included: regulatory and staff requirements (n = 5), equipment and technologies (n = 4), quality assurance (n = 1). System level included: referral process (n = 5), costing, budget impact and quality adjusted life years (n = 2), eligible patient estimates (n = 1). Recommendations were released nationally in June 2021 and distributed to all 43 cancer programs in Canada. CONCLUSION: A pan-Canadian consensus-building approach was successful in creating an evidence-based, peer-reviewed suite of recommendations thatsupportapplication of consistent clinical criteria to inform treatment options, facility set-up and access to high quality proton therapy.

Virtual particle Monte Carlo: A new concept to avoid simulating secondary particles in proton therapy dose calculation.

BACKGROUND: In proton therapy dose calculation, Monte Carlo (MC) simulations are superior in accuracy but more time consuming, compared to analytical calculations. Graphic processing units (GPUs) are effective in accelerating MC simulations but may suffer thread divergence and racing condition in GPU threads that degrades the computing performance due to the generation of secondary particles during nuclear reactions. PURPOSE: A novel concept of virtual particle (VP) MC (VPMC) is proposed to avoid simulating secondary particles in GPU-accelerated proton MC dose calculation and take full advantage of the computing power of GPU. METHODS: Neutrons and gamma rays were ignored as escaping from the human body; doses of electrons, heavy ions, and nuclear fragments were locally deposited; the tracks of deuterons were converted into tracks of protons. These particles, together with primary and secondary protons, are considered to be the realistic particles. Histories of primary and secondary protons were replaced by histories of multiple VPs. Each VP corresponded to one proton (either primary or secondary). A continuous-slowing-down-approximation model, an ionization model, and a large angle scattering event model corresponding to nuclear interactions were developed for VPs by generating probability distribution functions (PDFs) based on simulation results of realistic particles using MCsquare. For efficient calculations, these PDFs were stored in the Compute Unified Device Architecture textures. VPMC was benchmarked with TOPAS and MCsquare in phantoms and with MCsquare in 13 representative patient geometries. Comparisons between the VPMC calculated dose and dose measured in water during patient-specific quality assurance (PSQA) of the selected 13 patients were also carried out. Gamma analysis was used to compare the doses derived from different methods and calculation efficiencies were also compared. RESULTS: Integrated depth dose and lateral dose profiles in both homogeneous and inhomogeneous phantoms all matched well among VPMC, TOPAS, and MCsquare calculations. The 3D-3D gamma passing rates with a criterion of 2%/2 mm and a threshold of 10% was 98.49% between MCsquare and TOPAS and 98.31% between VPMC and TOPAS in homogeneous phantoms, and 99.18% between MCsquare and TOPAS and 98.49% between VPMC and TOPAS in inhomogeneous phantoms, respectively. In patient geometries, the 3D-3D gamma passing rates with 2%/2 mm/10% between dose distributions from VPMC and MCsquare were 98.56 ± 1.09% in patient geometries. The 2D-3D gamma analysis with 3%/2 mm/10% between the VPMC calculated dose distributions and the 2D measured planar dose distributions during PSQA was 98.91 ± 0.88%. VPMC calculation was highly efficient and took 2.84 ± 2.44 s to finish for the selected 13 patients running on four NVIDIA Ampere GPUs in patient geometries. CONCLUSION: VPMC was found to achieve high accuracy and efficiency in proton therapy dose calculation.

Initiation of anti-hypertensive drugs and outcomes in patients with heart failure with preserved ejection fraction and persistent hypertension.

BACKGROUND: National heart failure (HF) guidelines recommend that in patients with HF with preserved ejection fraction (EF;HFpEF) and hypertension, systolic blood pressure (SBP) should be maintained below 130 mmHg. The objective of the study is to examine the association between initiation of anti-hypertensive drugs and outcomes in patients with HFpEF with persistent hypertension. METHODS: Of the 8873 hospitalized patients with HFpEF (EF ≥50%) with a history of hypertension without renal failure in Medicare-linked OPTIMIZE-HF, 3315 had a discharge SBP ≥130 mmHg, of whom 1971 were not receiving anti-hypertensive drugs, thiazides and calcium channel blockers, before hospitalization. Of these, 366 received discharge prescriptions for those drugs. We assembled a propensity score-matched cohort of 365 pairs of patients initiated and not initiated on anti-hypertensive drugs, balanced on 37 baseline characteristics. Hazard ratios (HR) and 95% confidence intervals (CI) for outcomes associated with anti-hypertensive drug initiation were estimated in the matched cohort. RESULTS: Matched patients (n = 730) had a mean age of 78 years; 67% were women and 17% African Americans. During 6 (median 2.5) years of follow-up, 66% of the patients died and 45% had HF readmission. HRs (95% CIs) for all-cause mortality at 30 days, 12 months and 6 years associated with anti-hypertensive drug initiation were 0.64 (0.30-1.36), 0.70 (0.51-0.97), and 0.95 (0.79-1.13), respectively. Respective HRs (95% CIs) for HF readmission were 1.65 (0.97-2.80), 1.18 (0.90-1.56) and 1.09 (0.88-1.35). CONCLUSIONS: Among hospitalized older patients with HFpEF with uncontrolled hypertension, the initiation of therapy with anti-hypertensive drugs was not associated with all-cause mortality or hospital readmission.

GPU-accelerated Monte Carlo-based online adaptive proton therapy: A feasibility study.

PURPOSE: To develop an online graphic processing unit (GPU)-accelerated Monte Carlo-based adaptive radiation therapy (ART) workflow for pencil beam scanning (PBS) proton therapy to address interfraction anatomical changes in patients treated with PBS. METHODS AND MATERIALS: A four-step workflow was developed using our in-house developed GPU-accelerated Monte Carlo-based treatment planning system to implement online Monte Carlo-based ART for PBS. The first step conducts diffeomorphic demon-based deformable image registration (DIR) to propagate contours on the initial planning CT (pCT) to the verification CT (vCT) to form a new structure set. The second step performs forward dose calculation of the initial plan on the vCT with the propagated contours after manual approval (possible modifications involved). The third step triggers a reoptimization of the plan depending on whether the verification dose meets the clinical requirements or not. A robust evaluation will be done for both the verification plan in the second step and the reopotimized plan in the third step. The fourth step involves a two-stage (before and after delivery) patient-specific quality assurance (PSQA) of the reoptimized plan. The before-delivery PSQA is to compare the plan dose to the dose calculated using an independent fast open-source Monte Carlo code, MCsquare. The after-delivery PSQA is to compare the plan dose to the dose recalculated using the log file (spot MU, spot position, and spot energy) collected during the delivery. Jaccard index (JI), dice similarity coefficients (DSCs), and Hausdorff distance (HD) were used to assess the quality of the propagated contours in the first step. A commercial plan evaluation software, ClearCheck™, was integrated into the workflow to carry out efficient plan evaluation. 3D Gamma analysis was used during the fourth step to ensure the accuracy of the plan dose from reoptimization. Three patients with three different disease sites were chosen to evaluate the feasibility of the online ART workflow for PBS. RESULTS: For all three patients, the propagated contours were found to have good volume conformance [JI (lowest-highest: 0.833-0.983) and DSC (0.909-0.992)] but suboptimal boundary coincidence [HD (2.37-20.76 mm)] for organs-at-risk. The verification dose evaluated by ClearCheck™ showed significant degradation of the target coverage due to the interfractional anatomical changes. Reoptimization on the vCT resulted in great improvement of the plan quality to a clinically acceptable level. 3D Gamma analyses of PSQA confirmed the accuracy of the plan dose before delivery (mean Gamma index = 98.74% with a threshold of 2%/2 mm/10%), and after delivery based on the log files (mean Gamma index = 99.05% with a threshold of 2%/2 mm/10%). The average time cost for the complete execution of the workflow was around 858 s, excluding the time for manual intervention. CONCLUSION: The proposed online ART workflow for PBS was demonstrated to be efficient and effective by generating a reoptimized plan that significantly improved the plan quality.

Technical note: Evaluation and second check of a commercial Monte Carlo dose engine for small-field apertures in pencil beam scanning proton therapy.

PURPOSE: To evaluate the accuracy of the RayStation Monte Carlo dose engine (RayStation MC) in modeling small-field block apertures in proton pencil beam scanning. Furthermore, we evaluate the suitability of MCsquare as a second check for RayStation MC. METHODS: We have enhanced MCsquare to model block apertures. To test the accuracy of both RayStation MC and the newly enhanced MCsquare, we compare the dose predictions of each to in-water dose measurements obtained using diode detectors and radiochromic film. Nine brass apertures with openings of 1, 2, 3, 4, and 5 cm and either 2 cm or 4 cm thickness were used in the irradiation of a water phantom. Two measurement setups were used, one with a range shifter and 119.7 MeV proton beam energy and the other with no range shifter and 147 MeV proton beam energy. To further test the validity of RayStation MC and MCsquare in modeling block apertures and to evaluate MCsquare as a second check tool, 10 small-field (average target volume 8.3 cm3 ) patient treatment plans were calculated by each dose engine followed by a statistical comparison. RESULTS: Comparing to the absolute dose measurements in water, RayStation MC differed by 1.2% ± 1.0% while MCsquare differed by -1.8% ± 3.7% in the plateau region of a pristine Bragg peak. Compared to the in-water film measurements, RayStation MC and MCsquare both performed well with an average 2D-3D gamma passing rate of 99.4% and 99.7% (3%/3 mm), respectively. A t-test comparing the agreement with the film measurements between RayStation MC and MCsquare suggested that the relative spatial dose distributions calculated by MCsquare and RayStation MC were statistically indistinguishable. Directly comparing the dose calculations between MCsquare and RayStation MC over 10 patients resulted in an average 3D-3D gamma passing rates of 98.5% (3%/3 mm) and 94.1% (2%/2 mm), respectively. CONCLUSION: The validity of RayStation MC algorithm for use with patient-specific apertures has been expanded to include small apertures. MCsquare has been enhanced to model apertures and was found to be an adequate second check of RayStation MC in this scenario.

In-Hospital Weight Loss and Outcomes in Patients With Heart Failure.

BACKGROUND: Acute decompensation of heart failure (HF) is often marked by fluid retention, and weight loss is a marker of successful diuresis. We examined the relationship between in-hospital weight loss and post-discharge outcomes in patients with HF. METHODS: We conducted a propensity score-matched study of 8830 patients hospitalized for decompensated HF in the Medicare-linked Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure (OPTIMIZE-HF) registry, in which 4415 patients in the weight-loss group and 4415 patients in the no-weight-loss group were balanced on 75 baseline characteristics. We defined weight loss as an admission-to-discharge weight loss of 1-30 kilograms, and we defined no weight loss as a weight gain or loss of < 1 kilogram. Hazard ratios (HRs) and 95% confidence intervals (CIs) for outcomes associated with weight loss were estimated. RESULTS: Patients had a mean age of 78 years, 57% were women, and 11% were African American. The median weight loss in the weight-loss group was 3.6 (interquartile range, 2.0-6.0) kilograms. HRs and 95% CIs for 30-day all-cause mortality, all-cause readmission and HF readmission associated with weight loss were 0.75 (0.63-0.90), 0.90 (0.83-0.99) and 0.83 (0.72-0.96), respectively. Respective 60-day HRs (95% CIs) were 0.80 (0.70-0.92), 0.91 (0.85-0.98) and 0.88 (0.79-0.98). These associations were attenuated and lost significance during 6 months of follow-up. CONCLUSIONS: Among older patients hospitalized for decompensated HF, in-hospital weight loss was associated with a lower risk of mortality and hospital readmission. These findings suggest that in-hospital weight loss, a marker of successful diuresis and decongestion, is also a marker of improved clinical outcomes.

Initiation of Anti-Hypertensive Drugs and Outcomes in Patients with Heart Failure with Reduced Ejection Fraction.

BACKGROUND: In patients with heart failure with reduced ejection fraction (HFrEF) and hypertension, systolic blood pressure is recommended to be maintained below 130 mmHg, although this has not been shown to be associated with improved outcomes. We examined the association between anti-hypertensive drug initiation and outcomes in patients with HFrEF. METHODS: In the Medicare-linked OPTIMIZE-HF, 7966 patients with HFrEF (ejection fraction ≤40%) without renal failure were not receiving anti-hypertensive drugs before hospitalization, of whom 692 received discharge prescriptions for those drugs (thiazides and calcium channel blockers). We assembled a propensity score-matched cohort of 687 pairs of patients initiated and not initiated on anti-hypertensive drugs, balanced on 38 baseline characteristics. Hazard ratios (HR) and 95% confidence intervals (CIs) for outcomes associated with anti-hypertensive drug initiation were estimated in the matched cohort. RESULTS: Matched patients (n = 1374) had a mean age of 74 years, 41% were female, 17% were African-American, 66% were discharged on renin-angiotensin system inhibitors and beta blockers, and 10% on aldosterone antagonists. During 6 (median 2.5) years of follow-up, 70% of the patients died and 53% had heart failure readmission. Anti-hypertensive drug initiation was not significantly associated with all-cause mortality (HR, 0.95; 95% CI, 0.83-1.07) or heart failure readmission (HR, 0.93; 95% CI, 0.80-1.07). Similar associations were observed during 30 days and 12 months of follow-up. CONCLUSIONS: Among hospitalized older patients with HFrEF receiving contemporary treatments for heart failure, initiation of an anti-hypertensive drug was not associated with a lower risk of all-cause mortality or hospital readmission.

Establishing Cost-Effective Allocation of Proton Therapy for Patients With Mediastinal Hodgkin Lymphoma.

PURPOSE: For curative treatment of Hodgkin lymphoma, radiation therapy benefit must be weighed against toxicity. Although more costly, proton radiation therapy reduces dose to healthy tissue, potentially improving the therapeutic ratio compared with photons. We sought to determine the cost-effectiveness of proton versus photon therapy for mediastinal Hodgkin lymphoma (MHL) based on reduced heart disease. METHODS AND MATERIALS: Our model approach was 2-fold: (1) Use patient-level dosimetric information for a cost-effectiveness analysis using a Markov cohort model. (2) Use population-based data to develop guidelines for policymakers to determine thresholds of proton therapy favorability for a given photon dose. The HD14 trial informed relapse risk; coronary heart disease risk was informed by the Framingham risk calculator modified by the mean heart dose (MHD) from radiation. Sensitivity analyses assessed model robustness and identified the most influential model assumptions. A 30-year-old adult with MHL was the base case using 30.6-Gy proton therapy versus photon intensity modulated radiation therapy. RESULTS: Proton therapy was not cost-effective in the base case for male ($129,000/ quality-adjusted life years [QALYs]) or female patients ($196,000/QALY). A 5-Gy MHD decrease was associated with proton therapy incremental cost-effectiveness ratio <$100,000/QALY in 40% of scenarios. The hazard ratio associating MHD and heart disease was the most influential clinical parameter. CONCLUSIONS: Proton therapy may be cost-effective a select minority of patients with MHL based on age, sex, and MHD reduction. We present guidance for clinicians using MHD to aid decision-making for radiation therapy modality.

Estimating the population health burden of Lyme disease in Ontario, Canada: a microsimulation modelling approach.

BACKGROUND: If untreated, Lyme disease can lead to long-term sequelae and post-treatment Lyme disease syndrome (PTLDS), resulting in reduced health-related quality of life. The objective of this study was to develop a microsimulation model to estimate the population-level health burden of Lyme disease in Ontario, Canada. METHODS: We developed a Lyme disease history model using microsimulation, simulating 100 000 people (mean age 37.6 yr, 51% female) from 2017 in Ontario over a lifetime risk of infection and time horizon. We extracted the sensitivity and specificity of the 2-tier testing recommended by the Canadian Public Health Laboratory Network, probabilities and health state utility values from the published literature and health administrative data. Our reported outcomes from our stochastic analysis include diagnosed cases of Lyme disease (stratified by stage), undiagnosed infections, sequelae, individuals with PTLDS and quality-adjusted life-years (QALYs) lost. RESULTS: Our model estimated 333 (95% confidence interval [CI] 329-337) infections over the lifetime of 100 000 simulated people (mean age 37.6 yr, 51% female), with 92% (95% CI 91%-93%) of infections diagnosed. Of those 308 people with Lyme Disease diagnoses, 67 (95% CI 65-69) developed sequelae (e.g., arthritic, cardiac, neurologic sequelae), and 34 (95% CI 33-35) developed PTLDS. Lyme disease resulted in a loss of 84.5 QALYs (95% CI 82.9-86.2) over the lifetime of the simulated cohort. Sensitivity and scenario analysis showed that increasing incidence rates of Lyme disease, potential underreporting, duration of PTLDS and quality of life (health state utility) associated with PTLDS had the greatest impact on health burden. INTERPRETATION: Lyme disease contributes considerable health burden in terms of QALYs lost. Our analysis provides evidence to understand the disease burden and lays the foundation to assess the cost-effectiveness of pharmaceutical and nonpharmaceutical interventions.

Indirect costs associated with out-of-country referral for proton therapy: a survey of adult and pediatric patients in Alberta, Canada.

BACKGROUND: Patients in Alberta, Canada are referred to the United States (US) for proton treatment. The Alberta Ministry of Health pays for the proton treatment and the cost of flights to and from the United States. This study aimed to determine the out-of-pocket expenses incurred by patients or patients' families. METHODS: An electronic survey was sent to 59 patients treated with proton therapy between January 2008 and September 2019. Survey questions asked about expenses related to travel to the US and those incurred while staying in the US, reimbursement of expenses, and whether any time away from work was paid or unpaid leave. RESULTS: Seventeen respondents (response rate, 29%) reported expenses of flights for family members (mean, CAD 1886; range CAD 0-5627), passports/visas and other travel costs (mean, CAD 124; range CAD 0-546), accommodation during travel to the US (mean, CAD 50; range CAD 0-563), food during travel to the US (mean, CAD 89; range CAD 0-338), accommodation in the US (rented home/apartment mean, CAD 7394; range CAD 3075-13,305; hotel mean, CAD 4730; range CAD 3564-5895; other accommodation mean CAD 2660; range CAD 0-13,842), transportation in the US (car mean, CAD 2760; range CAD 0-7649; bus/subway mean, CAD 413; range CAD 246-580), and food in the US (mean, CAD 2443; range 0-6921). Expenses were partially reimbursed or covered by not-for-profit organizations or government agencies for some patients (35%). Patients missed a mean of 59 days of work; accompanying family members missed an average of 34 days. For 29% this time away from work was paid, but unpaid for 71% of respondents. CONCLUSIONS: Multiple factors contributed to the expenses incurred including age of the patient, number of accompanying individuals, available accommodation, mode of transportation within the US, and whether the patient qualified for financial support. Added to this burden is the potential loss of wages for time away from work. The study showed a large variation in indirect costs for each family and supports actively seeking more opportunities for financial support for families with children with cancer.

Costs of Definitive Chemoradiation, Surgery, and Adjuvant Radiation Versus De-Escalated Adjuvant Radiation per MC1273 in HPV+ Cancer of the Oropharynx.

PURPOSE: De-escalated treatment for human papillomavirus (HPV)+ oropharynx squamous cell carcinoma (OPSCC) has shown promising initial results. Health-care policy is increasingly focusing on high-value care. This analysis compares the cost of care for HPV+ OPSCC treated with definitive chemoradiation (CRT), surgery and adjuvant radiation (RT), and surgery and de-escalated CRT on MC1273. METHODS AND MATERIALS: MC1273 is a prospective, phase 2 study evaluating adjuvant CRT to 30 to 36 Gy plus docetaxel for HPV+ OPSCC after surgery for high-risk patients. Matched standard-of-care control groups were retrospectively identified for patients treated with definitive CRT or adjuvant RT. Standardized costs were evaluated before radiation, during treatment (during RT), and at short-term (6 month) and long-term (7-24 month) follow-up periods. RESULTS: A total of 56 definitive CRT, 101 adjuvant RT, and 66 MC1273 patients were included. The CRT arm had more T3-4 disease (63% vs 17-21%) and higher N2c-N3 disease (52% vs 20-24%) vs both other groups. The total treatment costs in the CRT, adjuvant RT, and MC1273 groups were $47,763 (standard deviation [SD], $19,060], $57,845 (SD, $17,480), and $46,007 (SD, $9019), respectively, and the chemotherapy and/or RT costs were $39,936 (SD, $18,480), $26,603 (SD, $12,542), and $17,864 (SD, $3288), respectively. The per-patient, per-month, average short-term follow-up costs were $3860 (SD, $10,525), $1072 (SD, $996), and $972 (SD, $833), respectively, and the long-term costs were $978 (SD, $2294), $485 (SD, $1156), and $653 (SD, $1107), respectively. After adjustment for age, T-stage, and N-stage, treatment costs remained lower for CRT and MC1273 versus adjuvant RT ($45,450 and $47,114 vs $58,590, respectively; P < .001), whereas the total per-patient, per-month follow-up costs were lower in the MC1273 study group and adjuvant RT versus CRT ($853 and $866 vs $2030, respectively; P = .03). CONCLUSIONS: MC1273 resulted in 10% and 20% reductions in global costs compared with standard-of-care adjuvant RT and definitive CRT treatments. Substantial cost savings may be an added benefit to the already noted low toxicity and maintained quality of life of treatment per MC1273.

Systolic Blood Pressure and Outcomes in Older Patients with HFpEF and Hypertension.

BACKGROUND: New hypertension and heart failure guidelines recommend that systolic blood pressure (SBP) in patients with heart failure with preserved ejection fraction (HFpEF) and hypertension be lowered to <130 mm Hg. METHODS: Of the 6778 hospitalized patients with HFpEF and a history of hypertension in the Medicare-linked OPTIMIZE-HF registry, 3111 had a discharge SBP <130 mm Hg. Using propensity scores for SBP <130 mm Hg, we assembled a matched cohort of 1979 pairs with SBP <130 versus ≥130 mm Hg, balanced on 66 baseline characteristics (mean age, 79 years; 69% women; 12% African American). We then assembled a second matched cohort of 1326 pairs with SBP <120 versus ≥130 mm Hg. Hazard ratios (HRs) and 95% confidence intervals (CIs) for outcomes associated with SBP <130 and <120 mm Hg were separately estimated in the matched cohorts using SBP ≥130 mm Hg as the reference. RESULTS: HRs (95% CIs) for 30-day, 12-month, and 6-year all-cause mortality associated with SBP <130 mm Hg were 1.20 (0.91-1.59; P = 0.200), 1.11 (0.99-1.26; P = 0.080), and 1.05 (0.98-1.14; P = 0.186), respectively. Respective HRs (95% CIs) associated with SBP <120 mm Hg were 1.68 (1.21-2.34; P = 0.002), 1.28 (1.11-1.48; P = 0.001), and 1.11 (1.02-1.22; P = 0.022). There was no association with readmission. CONCLUSIONS: Among older patients with HFpEF and hypertension, compared with SBP ≥130 mm Hg, the new target SBP <130 mm Hg had no association with outcomes but SBP <120 mm Hg was associated with a higher risk of death but not of readmission. Future prospective studies need to evaluate optimal SBP treatment goals in these patients.

Sociodemographic Factors Influencing Rhegmatogenous Retinal Detachment Presentation and Outcome.

PURPOSE: The impact of sociodemographic factors on the presentation and outcomes of rhegmatogenous retinal detachment (RRD) in the United States has not been described. We analyzed the impact of these factors on the presenting fovea-on or off status of RRD, single operation anatomic success (SOAS) of repair, and postoperative visual acuity (VA). DESIGN: Retrospective, single-center, cohort study. PARTICIPANTS: Participants included 4061 patients from Wills Eye Hospital/Mid Atlantic Retina from February 2015 to February 2020. METHODS: Sociodemographic factors including age, gender, race, and regional mean household income (MHI) as determined by ZIP code were recorded. The VA at baseline and 12 months post-RRD repair was recorded. Multiple regression analysis was used to evaluate the relationship between sociodemographic factors to fovea-on or off presentation of RRD, SOAS, and 12-month VA. MAIN OUTCOME MEASURES: Foveal attachment at presentation of RRD, SOAS, and 12-month VA. RESULTS: Older age (odds ratio [OR], 1.34 per decade, 95% confidence interval [CI], 1.27-1.41, P < 0.001), male gender (OR, 1.27, 95% CI, 1.11-1.45, P < 0.001), non-White race (OR, 2.41, 95% CI, 1.92-3.03, P < 0.001), and lower MHI (OR, 0.94 per $10 000, 95% CI, 0.91-0.98, P = 0.005) were independent risk factors for fovea-off presentation of RD. The need for reoperation to repair RRD within 90 days was independently associated with fovea-off presentation (OR, 1.47, 95% CI, 1.24-1.74, P < 0.001) and non-White race (OR, 1.72, 95% CI, 1.27-2.39, P < 0.001). Finally, 12-month postoperative VA was worse in patients who were fovea-off (P < 0.001), older (P = 0.041), male (P = 0.038), and non-White (P = 0.007) but was not related to MHI (P = 0.24). CONCLUSIONS: These findings reveal associations between the sociodemographic factors and the presentation and outcomes of RRD. Physicians should be aware that socioeconomic disparities can negatively impact the prognosis of patients with RRD. Further study confirming these findings and efforts to mitigate their effects are warranted and will be of interest to the greater ophthalmology community.