Development and validation of a claims-based algorithm to identify moderate exacerbations in patients with asthma treated in the US.

INTRODUCTION: Definitions of moderate asthma exacerbation have been inconsistent, making their economic burden difficult to assess. An algorithm to accurately identify moderate exacerbations from claims data is needed. METHODS: A retrospective cohort study of Reliant Medical Group patients aged ≥18 years, with ≥1 prescription claim for inhaled corticosteroid/long-acting ß2-agonist, and ≥1 medical claim with a diagnosis code for asthma was conducted. The objective was to refine current algorithms to identify moderate exacerbations in claims data and assess the refined algorithm's performance. Positive and negative predictive values (PPV and NPV) were assessed via chart review of 150 moderate exacerbations events and 50 patients without exacerbations. Sensitivity analyses assessed alternative algorithms and compared healthcare resource utilization (HRU) between algorithm-identified patients (claims group) and those confirmed by chart review (confirmed group) to have experienced a moderate exacerbation. RESULTS: Algorithm-identified moderate exacerbations were: visit of ≤1 day with an asthma exacerbation diagnosis OR visit of ≤1 day with selected asthma diagnoses AND ≥1 respiratory pharmacy claim, excluding systemic corticosteroids, within 14 days after the first claim. The algorithm's PPV was 42%; the NPV was 78%. HRU was similar for both groups. CONCLUSION: This algorithm identified potential moderate exacerbations from claims data; however, the modest PPV underscores its limitations in identifying moderate exacerbations, although performance was partially due to identification of previously unidentified severe exacerbations. Application of this algorithm in future claims-based studies may help quantify the economic burden of moderate and severe exacerbations in asthma when an algorithm identifying severe exacerbations is applied first.

Frequency and economic burden of exacerbations in inhaled corticosteroid/long-acting beta-agonist-treated patients with asthma: A retrospective US claims study.

INTRODUCTION: Despite adherence to inhaled corticosteroid/long-acting ß2-agonist (ICS/LABA) therapy, many patients with asthma experience moderate exacerbations. Data on the impact of moderate exacerbations on the healthcare system are limited. This study assessed the frequency and economic burden of moderate exacerbations in patients receiving ICS/LABA. METHODS: Retrospective, longitudinal study analyzed data from Optum's de-identified Clinformatics® Data Mart Database recorded between October 1, 2015, and December 31, 2019. Eligibility criteria included patients ≥18 years of age with ≥1 ICS/LABA claim and ≥1 medical claim for asthma in the 12 months pre-index (first ICS/LABA claim). Primary objectives included describing moderate exacerbation frequency, and associated healthcare resource utilization (HRU) and costs. A secondary objective was assessing the relationship between moderate exacerbations and subsequent risk of severe exacerbations. Patients were stratified by moderate exacerbation frequency in the 12 months post index. Moderate exacerbations were identified using a newly developed algorithm. RESULTS: In the first 12 months post index 61.6% of patients experienced ≥1 moderate exacerbation. Mean number of asthma-related visits was 4.1 per person/year and median total asthma-related costs was $3544. HRU and costs increased with increasing exacerbation frequency. Outpatient and inpatient visits accounted for a similar proportion of these costs. Moderate exacerbations were associated with an increased rate and risk of future severe exacerbations (incidence rate ratio, 1.56; hazard ratio, 1.51 [both p < 0.001]). CONCLUSIONS: This study highlighted that a high proportion of patients continue to experience moderate exacerbations despite ICS/LABA therapy and subsequently experience increased economic burden and risk of future severe exacerbations.

Cost-Effectiveness Analysis of Pembrolizumab as an Adjuvant Treatment of Resected Stage IIB or IIC Melanoma in the United States.

INTRODUCTION: Pembrolizumab was approved in the US as adjuvant treatment of patients with stage IIB or IIC melanoma post-complete resection, based on prolonged recurrence-free survival vs. placebo in the Phase 3 KEYNOTE-716 trial. This study aimed to evaluate the cost-effectiveness of pembrolizumab vs. observation as adjuvant treatment of stage IIB or IIC melanoma from a US health sector perspective. METHODS: A Markov cohort model was constructed to simulate patient transitions among recurrence-free, locoregional recurrence, distant metastasis, and death. Transition probabilities from recurrence-free and locoregional recurrence were estimated via multistate parametric modeling based on patient-level data from an interim analysis (data cutoff date: 04-Jan-2022). Transition probabilities from distant metastasis were based on KEYNOTE-006 data and network meta-analysis. Costs were estimated in 2022 US dollars. Utilities were based on applying US value set to EQ-5D-5L data collected in trial and literature. RESULTS: Compared to observation, pembrolizumab increased total costs by $80,423 and provided gains of 1.17 quality-adjusted life years (QALYs) and 1.24 life years (LYs) over lifetime, resulting in incremental cost-effectiveness ratios of $68,736/QALY and $65,059/LY. The higher upfront costs of adjuvant treatment were largely offset by reductions in costs of subsequent treatment, downstream disease management, and terminal care, reflecting the lower risk of recurrence with pembrolizumab. Results were robust in one-way sensitivity and scenario analyses. At a $150,000/QALY threshold, pembrolizumab was cost-effective vs. observation in 73.9% of probabilistic simulations that considered parameter uncertainty. CONCLUSION: As an adjuvant treatment of stage IIB or IIC melanoma, pembrolizumab was estimated to reduce recurrence, extend patients' life and QALYs, and be cost-effective versus observation at a US willingness-to-pay threshold.

Propensity Scores in Health Disparities Research: The Example of Cognitive Aging and the Hispanic Paradox.

BACKGROUND: Individuals of Mexican ancestry in the United States experience substantial socioeconomic disadvantages compared with non-Hispanic white individuals; however, some studies show these groups have similar dementia risk. Evaluating whether migration selection factors (e.g., education) associated with risk of Alzheimer disease and related dementia (ADRD) explain this paradoxical finding presents statistical challenges. Intercorrelation of risk factors, common with social determinants, could make certain covariate patterns very likely or unlikely to occur for particular groups, which complicates their comparison. Propensity score (PS) methods could be leveraged here to diagnose nonoverlap and help balance exposure groups. METHODS: We compare conventional and PS-based methods to examine differences in cognitive trajectories between foreign-born Mexican American, US-born Mexican American, and US-born non-Hispanic white individuals in the Health and Retirement Study (1994-2018). We examined cognition using a global measure. We estimated trajectories of cognitive decline from linear mixed models adjusted for migration selection factors also associated with ADRD risk conventionally or with inverse probability weighting. We also employed PS trimming and match weighting. RESULTS: In the full sample, where PS overlap was poor, unadjusted analyses showed both Mexican ancestry groups had worse baseline cognitive scores but similar or slower rates of decline compared with non-Hispanic white adults; adjusted findings were similar, regardless of method. Focusing analyses on populations where PS overlap was improved (PS trimming and match weighting) did not alter conclusions. CONCLUSIONS: Attempting to equalize groups on migration selection and ADRD risk factors did not explain paradoxical findings for Mexican ancestry groups in our study.