Category: Nevin Manimala

Stat Med. 2026 Jun;45(13-14):e70586. doi: 10.1002/sim.70586.

ABSTRACT

There is a growing literature on estimating effects of treatment strategies based on the natural treatment that would have been received in the absence of intervention, often dubbed “modified treatment policies” (MTPs). MTPs are sometimes of interest because they are more realistic than interventions setting exposure to an ideal level for all members of a population. In the general time-varying setting, Richardson and Robins (2013) provided exchangeability conditions for nonparametric identification of MTP effects that could be deduced from single world intervention graphs (SWIGs). Díaz et al. (2023) provided multiply robust estimators under these identification assumptions that allow for machine learning nuisance regressions. In this paper, we fill a remaining gap by extending structural nested mean models (SNMMs) (Robins, 1994, 2004, Vansteelandt and Joffe, 2014) to MTP settings, which enables characterization of (time-varying) heterogeneity of MTP effects. We do this both under the exchangeability assumptions of Richardson and Robins (2013) and under parallel trends assumptions, which enables investigation of (time-varying heterogeneous) MTP effects in the presence of some unobserved confounding.

PMID:42186838 | DOI:10.1002/sim.70586

Healthc Policy. 2026 May;21(3):100-108. doi: 10.12927/hcpol.2026.27801.

ABSTRACT

The Ontario Wait Time Information System (WTIS) provides publicly accessible surgical wait time data. This study evaluated WTIS use among Ontario primary care physicians to understand how wait time information is interpreted and applied. We invited 1,306 physicians to complete an online survey. Of 151 respondents, 90.9% were unaware of the WTIS. However, 87.5% said hospital wait time data would influence referrals, and 95.1% preferred surgeon-specific wait times. In addition, 97.2% were willing to use a single-entry referral system. Increasing WTIS awareness and adding surgeon-level data may enhance referral practices.

PMID:42186837 | DOI:10.12927/hcpol.2026.27801

Healthc Policy. 2026 May;21(3):86-99. doi: 10.12927/hcpol.2026.27800.

ABSTRACT

BACKGROUND: Long wait times for elective surgery represent a persistent challenge in healthcare systems and for waiting patients, particularly in Canada. Delays to elective surgery impact patient well-being but may also disproportionately affect vulnerable populations. Despite high levels of immigration to Canada, research regarding immigrants’ access to elective surgical care remains scarce. This population-based study measures and compares wait times for common elective general surgeries for immigrants with non-immigrants in British Columbia (BC), Canada.

METHODS: All elective general surgery procedures performed in BC, Canada, between 2013 and 2021, were identified using hospital discharge summaries’ procedure codes. A longitudinal cohort was created by linking cohort members with immigration and physician billing data. Patients’ wait time was defined as the duration between the last general surgery visit and the surgery date. Wait times were compared between immigrants and non-immigrants, adjusting for patient- and system-level factors using multivariable regression.

RESULTS: Among 159,151 elective general surgeries, 14.3% were performed on immigrants. Immigrants experienced longer wait times on average compared with non-immigrants (83.7 vs 76.3 days), a difference that remained significant after adjustment (rate ratio [RR]: 1.03, 95% confidence interval [CI]: 1.01, 1.05). Differences were most pronounced for cholecystectomies; immigrants waited 15.4 days longer on average (unadjusted) than non-immigrants. Among immigrants, “visible minorities” waited longer compared with immigrants from European/English-speaking countries (RR: 1.06, 95% CI: 1.03, 1.10).

CONCLUSION: This study highlighted that immigrants tended to wait longer for elective surgery in this study’s setting. Visible minorities experienced the longest waits. Despite sharing the same structures and processes of care in the setting’s publicly funded health system, barriers in healthcare delivery delayed access to elective surgical care for immigrants.

PMID:42186836 | DOI:10.12927/hcpol.2026.27800

Healthc Policy. 2026 May;21(3):36-42. doi: 10.12927/hcpol.2026.27772.

ABSTRACT

Canadian healthcare confronts persistent surgical capacity constraints driven by demographic pressures, economic limitations and inefficient resource utilization. Despite substantial resource requirements, operating rooms frequently remain underutilized due to misaligned policies and incentives. Introducing “collectable time” provides a foundation for comprehensive policy reform to resolve these inefficiencies. Addressing these inefficiencies through detailed, multi-level policy changes is critical to sustainably improving healthcare system productivity. Embedding collectable time metrics within institutional, provincial, federal and regulatory frameworks could increase surgical capacity without requiring additional staff or infrastructure.

PMID:42186829 | DOI:10.12927/hcpol.2026.27772

Disabil Rehabil Assist Technol. 2026 May 26:1-22. doi: 10.1080/17483107.2026.2677768. Online ahead of print.

ABSTRACT

PURPOSE: Article 20 of the UN Convention on the Rights of Persons with Disabilities obliges States Parties to facilitate access to assistive products, yet population-level data for the Gulf remain scarce. Guided by the WHO GATE framework and the rATA tool, this study estimated current assistive-product use and unmet need among Kuwaiti adults and identified their sociodemographic and functional correlates.

MATERIALS AND METHODS: A cross-sectional mixed-methods online survey using a locally adapted Arabic rATA was disseminated via convenience and snowball sampling through Kuwait University, the Public Authority for Persons with Disability, civil-society organisations, and social media. Quantitative data were analysed using descriptive statistics, χ² tests, Cronbach’s alpha, and multivariable logistic regression; six interviews were analysed thematically.

RESULTS: Of 652 respondents (84.4% female; 62.4% aged 18-28), 18.9% reported diagnosed disability and 69.0% reported Washington Group functional difficulty. Current use was 41.1%, clustering in vision (83.2% of users), cognition (64.6%), and communication (53.7%). Unmet need was 8.6%, most often attributed to cost (46.4%). Among users, 54.1% self-funded and 10.8% received government funding. Satisfaction was highest for environmental fit (M = 4.12) and lowest for repair (M = 3.59; α = 0.72). Disability (aOR 9.18, 95% CI 5.25-16.06) and functional difficulty (aOR 4.85, 3.04-7.73) were the dominant correlates.

CONCLUSIONS: In this non-probability sample, assistive-product use was driven by disability and functional difficulty rather than socioeconomic position, yet most users self-funded and cost dominated unmet need. Strengthening publicly funded procurement, follow-up services, and product coverage beyond vision aids would align Kuwait with WHO GATE and CRPD obligations-findings directly relevant to rehabilitation service planning.

PMID:42186824 | DOI:10.1080/17483107.2026.2677768

Stat Med. 2026 Jun;45(13-14):e70599. doi: 10.1002/sim.70599.

ABSTRACT

Progressive multi-state survival outcomes are common in trials with recurrent or sequential events and require treatment effect estimands that remain interpretable without proportional intensity or Markov assumptions. The restricted mean time in favor of treatment (RMT-IF) extends the restricted mean survival time to ordered multi-state processes and provides such an interpretable estimand. However, existing RMT-IF methods are nonparametric, assume covariate-independent censoring for independent observations, and do not accommodate cluster-randomized trials (CRTs), limiting both efficiency and applicability. We develop a class of doubly robust estimators for RMT-IF under right censoring using an augmented inverse-probability weighting framework that combines stage-specific outcome regression with arm-specific censoring models, yielding consistency when either nuisance model is correctly specified. We further extend the framework to CRTs by formalizing both cluster-level and individual-level average RMT-IF estimands to address informative cluster size and by constructing corresponding doubly robust estimators that account for within-cluster correlation. For inference, we employ model-agnostic jackknife variance estimators in both individually randomized and cluster-randomized settings. Extensive simulation studies demonstrate finite-sample performance, and the methods are illustrated using two randomized trial examples.

PMID:42186819 | DOI:10.1002/sim.70599

Alzheimers Dement. 2026 May;22(5):e71481. doi: 10.1002/alz.71481.

ABSTRACT

INTRODUCTION: The Dementia DataHub (DDH) reports U.S. dementia prevalence and incidence from Medicare data. Variation in sensitivity, specificity, and accuracy of diagnoses related to geography and participant characteristics complicates the interpretation of these data.

METHODS: We evaluated performance of DDH-defined Medicare claims diagnoses against linked Health and Retirement Study (HRS) survey-based dementia classifications.

RESULTS: DDH’s likely-or-higher dementia definition achieved 50% sensitivity, 97% specificity, and 91% accuracy relative to the HRS classification. Sensitivity, specificity, and accuracy varied across census divisions and by urbanicity. Respondents with dementia missed in claims were younger and healthier than those correctly identified.

DISCUSSION: Medicare claims reflecting diagnoses of dementia provide valuable information about who may be receiving dementia treatment and where; however, they often miss cases in ways that differ by geography and patient characteristics. Variation in diagnosis in Medicare claims relative to HRS survey-based dementia classification can be used to improve the value of Medicare diagnoses for surveillance purposes.

PMID:42186810 | DOI:10.1002/alz.71481

Circulation. 2026 May 26. doi: 10.1161/CIRCULATIONAHA.126.079484. Online ahead of print.

ABSTRACT

BACKGROUND: Catheter ablation for atrial fibrillation (AF) is one of the most common cardiovascular procedures being performed worldwide. Despite the large body of evidence of its effectiveness, with a single exception, prior ablation studies were largely unblinded trials. Accordingly, residual concerns remained about placebo effects, both for AF recurrence and, in particular, on subjective outcomes such as quality of life or anxiety. Here, we compared pulsed field ablation (PFA) with a sham procedure to treat patients with symptomatic AF.

METHODS: This prospective, sham-controlled, single-blind, randomized clinical trial with blinded end-point assessment enrolled patients with AF that was highly symptomatic (Atrial Fibrillation Effect on Quality-of-Life score <50). Patients were assigned 1:1 to PFA or a sham procedure. All participants received implantable cardiac monitors for continuous rhythm monitoring during follow-up. The 6-month co-primary outcomes were (1) time to first recurrence of atrial tachyarrhythmia and (2) changes from baseline in Atrial Fibrillation Effect on Quality-of-Life scores compared between groups. Secondary outcomes were AF burden and psychological distress (assessed by the Hospital Anxiety and Depression Scale [HADS]).

RESULTS: Patients (n=60) were randomized to PFA or sham. At 6 months, the first co-primary end point of AF recurrence was met in 2 patients (6.7%) who underwent PFA and 25 patients (83.3%) who underwent sham (posterior hazard ratio, 19.6 [95% bayesian credible intervals, 6.7-76.9]; posterior probability of superiority >0.99). For the second co-primary end point, Atrial Fibrillation Effect on Quality-of-Life scores showed greater improvement from baseline with PFA than sham (improved by 43.9+18.1 points versus 11.3+27.9 points; posterior median difference, 32.6 [95% bayesian credible interval, 20.2-44.9]; posterior probability of superiority >0.99). AF burden at 6 months was significantly lower in the PFA than the sham group (0 [0-0] versus 0.43 [0.04-3.47]; between group median difference, -0.39 [95% credible interval, -2.5 to -0.1], posterior probability of superiority >0.99). The Hospital Anxiety and Depression Scale score changed by -4 points (-7.8 to -2.0) with PFA and by -0.5 (-4.5 to 1.0) with sham (group median difference, -3.5 [95% credible interval, -6.0 to -1.0]; posterior probability of superiority >0.99).

CONCLUSIONS: In patients with AF, PFA was superior to sham in reducing arrhythmia recurrences and burden and improving quality of life and AF-associated psychological distress.

PMID:42186803 | DOI:10.1161/CIRCULATIONAHA.126.079484

COPD. 2026 May 11;23(1):2672702. doi: 10.1080/15412555.2026.2672702. Epub 2026 May 26.

ABSTRACT

Exacerbation of chronic obstructive pulmonary disease (ECOPD) frequently coexists with diabetes mellitus, creating competing priorities for respiratory stabilization and safe inpatient glycemic control. Evidence for an integrated, respiratory-endocrinology co-management pathway in this population remains limited. A total of 162 inpatients hospitalized with ECOPD and comorbid diabetes between January 1 and December 31, 2025 were randomly allocated to a respiratory-endocrinology multidisciplinary co-management pathway or usual care. The intervention comprised an ECOPD care bundle, protocolized glycemic management, pulmonary rehabilitation, and a structured discharge transition package. Primary outcomes were chronic airways assessment test (CAAT) and patient-day hyperglycemia/hypoglycemia. Secondary outcomes included length of stay, 30-day readmission, functional capacity assessed by the 1-min sit-to-stand (1-min STS) test (at discharge and 30 days), patient satisfaction (CSQ-8; at discharge and 30 days), and care-transition quality measured by the Care Transitions Measure-3 (CTM-3; at 7 and 30 days). Compared with usual care, co-management yielded clinically meaningful improvements in CAAT at discharge and at 30 days. Co-management reduced hyperglycemic patient-days (rate ratio 0.799) without an increase in mild, moderate or severe hypoglycemia. The intervention group also had a shorter length of stay, a lower 30-day readmission rate, higher CSQ-8 scores, higher CTM-3 scores, and greater 1-min sit-to-stand performance at discharge and 30 days. Findings were consistent in sensitivity analyses restricted to systemic corticosteroid recipients. A structured respiratory-endocrinology multidisciplinary co-management pathway improved ECOPD-related health status and inpatient glycemic safety while enhancing functional recovery, patient experience, and short-term utilization outcomes in hospitalized patients with ECOPD and diabetes.

PMID:42186793 | DOI:10.1080/15412555.2026.2672702

Addiction. 2026 May 26. doi: 10.1111/add.70474. Online ahead of print.

ABSTRACT

BACKGROUND AND AIMS: With expanding cannabis legalization, normalization, and diversifying products and delivery methods in the United States (US), cannabis use disorder (CUD) prevalence is rising. Various modes of cannabis use may influence pharmacokinetics, usage patterns, and harm, affecting CUD risk. We measured associations between modes of cannabis use, including multi-modal patterns, and CUD prevalence and severity.

DESIGN AND SETTING: This cross-sectional study analyzed data from a nationally representative sample of US adults using the 2022-2023 National Survey on Drug Use and Health (NSDUH) data. Multivariable logistic regression analyses were employed to estimate the association between modes of cannabis use and past-year CUD, adjusting for potential confounders and covariates. Analyses were stratified by sex, age, and cannabis use frequency. Among multi-modal users, common combinations and their associations with CUD were further examined.

PARTICIPANTS/CASES: Respondents 18 years or older who reported past-year cannabis use (unweighted n = 25 549; weighted N = 58 850 309).

MEASUREMENTS: Exposure of interest was the mode of cannabis use, primarily categorized as smoke-only, vape-only, oral/mucosal-only, dab-only, topicals-only, and multi-modal (≥ two modes). The outcome variable was CUD in the past year, and CUD severity, based on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria. Covariates included age, sex, race/ethnicity, income, education, state cannabis law status, age of cannabis initiation, cannabis use motive, frequency of use, perceived risk of smoking cannabis, illicit drug use, past year mental illness, nicotine dependence, and alcohol use disorder.

FINDINGS: Of the total past-year cannabis users, 53.9% reported multi-modal cannabis use. Overall, CUD prevalence was 30.3%, ranging from 4.4% among oral/mucosal-only to 40.5% among multi-modal, and 28.9% among dab-only users (p < 0.0001). Moderate-to-severe CUD affected 13.2% of all users and was concentrated among multi-modal and dab-only users. In multivariable regression, multi-modal users had fourfold higher odds of CUD (adjusted odds ratio [AOR] = 4.14; 95% confidence interval [CI]: 2.91-5.90). Elevated odds were also observed among smoke-only (AOR = 2.98; 95% CI: 2.02-4.39) and vape/dab-only users (AOR = 1.89; 95% CI: 1.09-3.29), compared with oral/mucosal-only users. Analyses of multi-modal combinations showed the highest CUD odds among those using smoke + vape + oral/mucosal + dab (AOR = 19.74; 95% CI: 9.11-42.75), compared with oral/mucosal + topicals users.

CONCLUSIONS: In the United States, modes of cannabis use appear to be statistically significantly associated with prevalence and severity of cannabis use disorder, with multi-modal and inhaled routes conferring the greatest risk. Findings underscore the importance of considering mode of use alongside frequency and potency in clinical assessment, prevention, and policy strategies aimed at reducing cannabis-related harms.

PMID:42186749 | DOI:10.1111/add.70474