Background: Alzheimer’s Disease (AD) can be conceptualized as a continuum: patients progress from normal cognition to mild cognitive impairment (MCI) due to AD, followed by increasing severity of AD dementia. Prior research has measured transition probabilities among later stages of AD, but not for the complete spectrum. Objective: To estimate annual progression rates across the AD continuum and evaluate the impact of a delay in MCI due to AD on the trajectory of AD dementia and clinical outcomes. Methods: Patient-level longitudinal data from the National Alzheimer’s Coordinating Center for n=18,103 patients with multiple visits over the age of 65 were used to estimate annual, age-specific transitional probabilities between normal cognition, MCI due to AD, and AD severity states (defined by Clinical Dementia Rating score). Multivariate models predicted the likelihood of death and institutionalization for each health state, conditional on age and time from the previous evaluation. These probabilities were used to populate a transition matrix describing the likelihood of progressing to a particular disease state or death for any given current state and age. Finally, a health state model was developed to estimate the expected effect of a reduction in the risk of transitioning from normal cognition to MCI due to AD on disease progression rates for a cohort of 65-year-old patients over a 35-year time horizon. Results: Annual transition probabilities to more severe states were 8%, 22%, 25%, 36%, and 16% for normal cognition, MCI due to AD, and mild/moderate/severe AD, respectively, at age 65, and increased as a function of age. Progression rates from normal cognition to MCI due to AD ranged from 4% to 10% annually. Severity of cognitive impairment and age both increased the likelihood of institutionalization and death. For a cohort of 100 patients with normal cognition at age 65, a 20% reduction in the annual progression rate to MCI due to AD avoided 5.7 and 5.6 cases of MCI due to AD and AD, respectively. This reduction led to less time spent in severe AD dementia health states and institutionalized, and increased life expectancy. Conclusion: Transition probabilities from normal cognition through AD severity states are important for understanding patient progression across the AD spectrum. These estimates can be used to evaluate the clinical benefits of reducing progression from normal cognition to MCI due to AD on lifetime health outcomes.

Design, study conduct, and financial support for this study were provided by AbbVie. AbbVie participated in the interpretation of data, review, and approval of the abstract. All authors contributed to the development of the publication and maintained control over the final content. Rubin has received consulting fees or research support from AbbVie, Amgen, Emmi, Genentech, Ironwood, Janssen, Pfizer, Prometheus, Shire, and Takeda. Skup and Mittal are employees and stockholders of AbbVie. Chao was an employee of AbbVie at the time of the study and may hold AbbVie stock. Johnson and Davis are employees of Medicus Economics, which received payment from AbbVie to participate in this research. Study concept and design were contributed by Rubin, Mittal, Chao, and Skup, along with Davis and Johnson. Davis and Johnson took the lead in data collection, with assistance from the other authors, and data interpretation was performed by Rubin, Mittal, Chao, and Skup, with assistance from Davis and Johnson. All authors contributed to the writing and revision of the manuscript. The abstract for this study was published as Rubin DT, Skup M, Davis M, Johnson S, Chao J. Impact of AbbVie's patient support program on resource costs in Crohn's disease, ulcerative colitis, rheumatoid arthritis, psoriasis, psoriatic arthritis, and ankylosing spondylitis. J Manag Care Spec Pharm. 2015;21(Suppl 4a):S74-75 (poster presentation at Academy of Managed Care, 27th Annual Meeting and Expo; April 7-10, 2015; San Diego, CA) and as abstract 2339 in Arthritis Rheumatol. 2015;67(Suppl 10; poster presentation at American College of Rheumatology 2015 ACR/AHRP Annual Meeting; November 7-11, 2015; San Francisco, CA).

BACKGROUND: The U.S. health care system is currently evolving from a volume-based care to a value-based care approach, which is in part supported by the introduction of patient support programs (PSP). For patients treated with adalimumab (ADA), the addition of a dedicated, trained nurse to the PSP (HUMIRA Complete, rolled out nationally in 2015) provides further emphasis on value-based care.OBJECTIVE: To determine the effectiveness of the HUMIRA Complete PSP, including the Nurse Ambassador component, in a real-world setting for patients receiving ADA across a broad range of approved indications (rheumatoid arthritis, Crohn's disease, ulcerative colitis, psoriasis, psoriatic arthritis, ankylosing spondylitis, uveitis, and hidradenitis suppurativa).METHODS: A longitudinal retrospective study was conducted using patientlevel data from the HUMIRA Complete PSP data linked to the real-world, patient-level Symphony Health Solutions administrative claims database. Commercially insured patients were included who were aged ≥ 18 years with ≥ 2 diagnoses of an indicated disease who were biologically naive before initiating ADA or who had no claims for synthetic-targeted immune modulator therapy before their earliest ADA claim in the database between January 2015 and February 2017. The first claim had to have occurred in 2015 or later, and continuous medical and drug data coverage were required for ≥ 6 months before and ≥ 12 months after the first ADA claim and index date. PSP patients (with at least an initial and follow-up dedicated nurse call) were matched 1:1 to non-PSP patients based on pharmacy type, indication, and propensity score, estimated with covariates for age, sex, year of first ADA use, and baseline comorbidities. Adherence to ADA was compared using proportion of days covered along with discontinuation of ADA, defined as a gap in treatment greater than the previous days supply with no additional ADA claim, total costs, medical costs, and drug costs (2017 U.S. dollars) over 12 months. Baseline demographic and clinical characteristics were summarized descriptively. Differences between cohorts were assessed using t-tests for adherence and costs and log-rank tests for discontinuation. RESULTS: 2,268 patients (1,134 per group) were included. Baseline characteristics were similar between cohorts after matching. Participation in the PSP was associated with 29.3% higher ADA adherence (64.8% vs. 50.1%; P < 0.0001) and 22.0% lower ADA discontinuation rate (51.4% vs.

Oxiranes are a class of cyclic ethers formed in abundance during lowtemperature combustion of hydrocarbons and biofuels, either via chainpropagating steps that occur from unimolecular decomposition of βhydroperoxyalkyl radicals (β-QOOH) or from reactions of HOȮ with alkenes. The cis-and trans-isomers of 2,3-dimethyloxirane are intermediates of n-butane oxidation, and while rate coefficients for β-QOOH → 2,3-dimethyloxirane +ȮH are reported extensively, subsequent reaction mechanisms of the cyclic ethers are not. As a result, chemical kinetics mechanisms commonly adopt simplified chemistry to describe the consumption of 2,3-dimethyloxirane by convoluting several elementary reactions into a single step, which may introduce mechanism truncation error-uncertainty derived from missing or incomplete chemistry. The present research examines the isomer dependence of 2,3-dimethyloxirane reaction mechanisms in support of ongoing efforts to minimize mechanism truncation error. Reaction mechanisms are inferred via the detection of products from Cl-initiated oxidation of both cis-2,3-dimethyloxirane and trans-2,3-dimethyloxirane using multiplexed photoionization mass spectrometry (MPIMS). The experiments were conducted at 10 Torr and temperatures of 650 K and 800 K. To complement the experiments, the enthalpies of stationary points on theṘ + O 2 surfaces were computed at the ccCA-PS3 level of theory. In total, 28 barrier heights were computed on the 2,3-dimethyloxiranylperoxy surfaces. Two notable aspects are low-lying pathways that form resonancestabilized ketohydroperoxide-type radicals caused byQOOH ring-opening when the unpaired electron is localized adjacent to the ether group, and cis-trans isomerization ofṘ andQOOH radicals, via inversion, which enable reaction pathways otherwise restricted by stereochemistry. Several species were identified in the MPIMS experiments from ring opening of 2,3-dimethyloxiranyl radicals. Neither of the two conjugate alkene isomers prototypical ofṘ + O 2 reactions were detected. Products were also identified from decomposition of ketohydroperoxide-type radicals. The present work

Oxiranes are a class of cyclic ethers formed in abundance during lowtemperature combustion of hydrocarbons and biofuels, either via chainpropagating steps that occur from unimolecular decomposition of βhydroperoxyalkyl radicals (β-QOOH) or from reactions of HOȮ with alkenes. Ethyloxirane is one of four alkyl-substituted cyclic ether isomers produced as an intermediate from n-butane oxidation. While rate coefficients for β-QOOH → ethyloxirane +ȮH are reported extensively, subsequent reaction mechanisms