Probability Weighting Research Articles

Application of High-Dimensional Propensity Score Methods to the National Health and Aging Trends Study.

High-dimensional propensity scoring (HDPS) is a method for empirically identifying potential confounders within large healthcare databases such as administrative claims data. However, this method has not yet been applied to large national health surveys such as the National Health and Aging Trends Study (NHATS), an ongoing nationally representative survey of older adults in the United States and important resource in gerontology research. In this Research Practice article, we present an overview of HDPS and describe the specific data transformation steps and analytic considerations needed to apply it to national health surveys. We applied HDPS within NHATS to investigate the association between self-reported visual difficulty and incident dementia, comparing HDPS to conventional confounder selection methods. Among 7 207 dementia-free NHATS Wave 1 respondents, 528 (7.3%) had self-reported visual difficulty. In an unadjusted discrete time proportional hazards model accounting for the complex survey design of NHATS, self-reported visual difficulty was strongly associated with incident dementia (odds ratio [OR] 2.34, 95% confidence interval [CI]: 1.95-2.81). After adjustment for standard investigator-selected covariates via inverse probability weighting, the magnitude of this association decreased, but evidence of an association remained (OR 1.44, 95% CI: 1.11-1.85). Adding 75 HDPS-prioritized variables to the investigator-selected propensity score model resulted in further attenuation of the association between visual impairment and dementia (OR 0.94, 95% CI: 0.70-1.23). HDPS can be successfully applied to national health surveys such as NHATS and may improve confounder adjustment. We hope developing this framework will encourage future consideration of HDPS in this setting.

A hospital lipid-lowering protocol improves 2-year clinical outcomes in patients with acute coronary syndrome.

Although mortality after acute coronary syndrome (ACS) has improved in the acute phase, cardiovascular events occur at a certain frequency in the chronic phase. A hospital lipid-lowering protocol (HLP) could be effective in providing optimal lipid-lowering therapy to improve long-term clinical outcomes after ACS. This study investigated the impact of HLP on clinical outcomes in patients with ACS. We retrospectively analysed 1,114 ACS patients who had undergone successful percutaneous coronary intervention between November 2011 and June 2021. In December 2018, we introduced a HLP that included the prescription of the maximum tolerated dose of statin, ezetimibe, and eicosapentaenoic acid after ACS treatment. We compared 2-year clinical outcomes before (control group: 791 patients) and after the HLP's introduction (HLP group: 323 patients). The primary outcome was the non-target vessel revascularisation (non-TVR) rate. A multivariate Cox proportional hazard model and inverse probability weighting (IPW) based on the propensity score were used to evaluate the effect of HLP on the outcomes. The cumulative 2-year non-TVR incidence was significantly lower in the HLP group than in the control group (8.5% vs 13.8%; p=0.019). Multivariable analysis revealed non-TVR risk was significantly lower in the HLP group than in the control group (adjusted hazard ratio [aHR]: 0.637 [95% confidence interval [CI]: 0.416-0.975]; p=0.038). The IPW analysis confirmed a significant association between the HLP and a lower non-TVR risk (aHR: 0.544 [95% CI: 0.350-0.847]; p=0.007). Implementing HLP for ACS patients improved the 2-year clinical outcome.

Comparison of oral versus intravenous antimicrobial therapy for patients who were diagnosed with bloodstream infections due to Gram-negative bacilli after discharge from the emergency department: A retrospective analysis

IntroductionInfections caused by Gram-negative bacilli (GNB) in the emergency department (ED) are common, and the blood cultures taken at the visit can turn positive often after the discharge. However, the differences in the clinical outcomes depending on the subsequent decision-making, either to giving the patients intravenous or oral antibiotics remain unknown. MethodsA single-center retrospective observational study was conducted for the outcome of the patients whose blood cultures at the visit turned positive and detected GNB. The primary outcomes were 30- and 90-day all-cause mortality from the first positive blood cultures, comparing intravenous treatment (IVT) and oral treatment (OT). The propensity score analysis was used to adjust potential confounders. ResultsA total of 283 patients with GNB bloodstream infections (BSIs) diagnosed after ED discharge. No death occurred in either group within 30 days, with the average treatment effect (ATE) of OT being <0.001 (p = 0.45) after inverse probability weighting (IPW). At 90 days, mortality was 2.5 % for the OT group and 0 % for the IVT group (ATE 0.051; 96%CI 0.013–0.098; p = 0.001). ConclusionAll of patients treated with oral antibiotics were alive at 30 days, but had a higher 90-day mortality compared to those given intravenous agents. The results were consistent after adjusting the potential confounders by using IPW. Given the overall low mortality in both groups after 90 days, even though oral antibiotic therapy was associated with higher mortality statistically, one might consider this as an option especially when the patient's preference was compelling.

Retroperitoneal vs transperitoneal approach for nonruptured open conversion after endovascular aneurysm repair

ObjectiveSeveral studies comparing the transperitoneal (TP) and retroperitoneal (RP) approach for abdominal aortic aneurysm (AAA) repair suggest that the RP approach may result in lower rates of perioperative mortality and morbidity. However, data comparing these approaches for open conversion are lacking. This study aims to evaluate the association between the type of approach and outcomes following open conversion after endovascular aneurysm repair (EVAR). MethodsWe included all patients who underwent open conversion after EVAR between 2010 and 2022 in the Vascular Quality Initiative. Patients presenting with rupture were excluded. The primary outcome was perioperative mortality. The secondary outcomes included perioperative complications and 5-year mortality. Inverse probability weighting was used to adjust for factors with statistical or clinical significance. Logistic regression was used to assess perioperative mortality and complications in the weighted cohort. The 5-year mortality was evaluated using Kaplan-Meier and Cox regression. ResultsWe identified 660 patients (39% RP) who underwent open conversion after EVAR. Compared with TP, RP patients were older (75 years [interquartile range, 70-79 years] vs 73.5 years [interquartile range, 68-79 years]; P < .001), and more frequently had prior myocardial infarction (33% vs 22%; P = .002). Compared with the TP approach, the RP approach was used less frequently in cases of associated iliac aneurysm (19% vs 27%; P = .026), but more frequently with associated renal bypass (7.8% vs 1.7%; P < .001) and by high-volume physicians (highest quintile, >7 AAA annually: 41% vs 17%; P < .001) and in high-volume centers (highest quintile, >35 AAA annually: 36% vs 20%; P < .001). RP patients, compared with TP patients, were less likely to have external iliac or femoral distal anastomosis (8.2% vs 21%; P < .001), and an infrarenal clamp (25% vs 36%; P < .001). Unadjusted perioperative mortality was not significantly different between approaches (RP vs TP: 3.8% vs 7.5%; P = .077). After risk adjustment, RP patients had similar odds of perioperative mortality (adjusted odds ratio [aOR], 0.49; 95% confidence interval [CI], 0.22-1.10; P = .082), and lower odds of intestinal ischemia (aOR, 0.26; 95% CI, 0.08-0.86; P = .028) and in-hospital reintervention (aOR, 0.43; 95% CI, 0.22-0.85; P = .015). No significant differences were found in the other perioperative complications or 5-year mortality (aHR, 0.79; 95% CI, 0.47-1.32; P = .37). ConclusionsOur findings suggest that the RP approach may be associated with a lower adjusted odds of perioperative complications compared with the TP approach. The RP approach should be considered for open conversion after EVAR when feasible.

Predicting resistance and pseudoprogression: are minimalistic immunoediting mathematical models capable of forecasting checkpoint inhibitor treatment outcomes in lung cancer?

Background:The increased application of immune checkpoint inhibitors (ICIs) targeting PD-1/PD-L1 in lung cancer treatment generates clinical need to reliably predict individual patients’ treatment outcomes. Methods:To bridge the prediction gap, we examine four different mathematical models in the form of ordinary differential equations, including a novel delayed response model. We rigorously evaluate their individual and combined predictive capabilities with regard to the patients’ progressive disease (PD) status through equal weighting of model-derived outcome probabilities. Results:Fitting the complete treatment course, the novel delayed response model (R2=0.938) outperformed the simplest model (R2=0.865). The model combination was able to reliably predict patient PD outcome with an overall accuracy of 77% (sensitivity = 70%, specificity = 81%), solely through calibration with primary tumor longest diameter measurements. It autonomously identified a subset of 51% of patients where predictions with an overall accuracy of 81% (sensitivity = 81%, specificity = 81%) can be achieved. All models significantly outperformed a fully data-driven machine learning-based approach. Implications: These modeling approaches provide a dynamic baseline framework to support clinicians in treatment decisions by identifying different treatment outcome trajectories with already clinically available measurement data. Limitations and future directions:Conjoint application of the presented approach with other predictive tools and biomarkers, as well as further disease information (e.g. metastatic stage), could further enhance treatment outcome prediction. We believe the simple model formulations allow widespread adoption of the developed models to other cancer types. Similar models can easily be formulated for other treatment modalities.

Persistent low job control and subsequent major depression: A prospective cohort study of Australian working males

Workers' perception of control over work is a key construct in the relationship between the psychosocial work environment and health. While exposure to low job control has been prospectively linked to poor mental health including depression and anxiety, there is less research examining the impact of prolonged exposure to low job control on mental health. Data from 5054 employed men from 2013 to 2021 in the Australian Longitudinal Study on Male Health was used to examine persistent and intermittent low job control and subsequent major depression symptoms. Persistent low job control was based on consecutive self-reports of low job control over waves 1 and 2. Combinations of low and high job control were classified as intermittent exposure and continuous high job control exposure over both waves was classified as persistent high job control. Major depression symptoms, derived from the Patient Health Questionnaire-9, was measured in wave 3. Generalised linear models and augmented inverse probability weighting were undertaken. There was a strong stepwise relationship between low job control and major depression. Compared to persistent high job control, intermittent low job control was associated with an increased risk of subsequent major depression symptoms by 32% (RR 1.32, 95% CI 0.82, 2.15); and persistent low job control by 103% (RR 2.03, 95% CI 1.21, 3.41). Compared to men exposed to persistent high job control, the average treatment effect for persistent low job control was 0.036 (95%CI 0.014, 0.058) and intermittent low job control 0.019 (95%CI 0.006, 0.032) equating to a risk ratio of 2.46 (95%CI 1.43, 3.50) and 1.79 (95% CI 1.14, 2.45) respectively. This study's findings have implications for public health and occupational policies, as they underscore the importance of reducing prolonged exposure to low job control to protect against the risk of major depression in the working population.

Lifetime physical activity influences Parkinson's disease progression

IntroductionPast studies suggested that Parkinson's disease (PD) patients who engage in physical activity (PA) after diagnosis have slower motor progression. Here, we examine the influence of lifetime PA prior to PD onset on motor, cognitive, and overall functional decline among PD patients. MethodsFor 495 participants in the Parkinson's Environment and Gene (PEG) studies, we collected PA-related measures through interviews and quantified these using metabolic equivalents (MET) scores. PD progression was defined as time to a Unified Parkinson's Disease Rating Scale Part III (UPDRS-III) conversion to ≥ 35 points, Hoehn and Yahr (H&Y) ≥ 3, and a 4-point decline in Mini‐Mental State Examination (MMSE). We used Cox frailty models to estimate hazard ratios and inverse probability weights to account for heterogeneity by enrollment wave and censoring. ResultsFor PD patients reporting the highest lifetime strenuous MET-h/wk (highest quartile), we estimated a lower HR for time-to-UPDRS-III-conversion (Q4 vs. Q1: HR = 0.56, 95 % CI = [0.36, 0.87]). Additionally, having engaged in any competitive sport also reduced the risk of reaching a UPDRS-III ≥ 35 points (low vs. none: HR = 0.61, 95 % CI = [0.44, 0.86]; high vs. none: HR = 0.63; 95 % CI = [0.44,0.86]); high levels of sports activities also affected progression on the H&Y scale (high vs. none: HR = 0.73; 95 % CI = [0.46,1.00]). Lifetime PA measures did not affect time-to-MMSE decline. ConclusionOur study suggests that PD patients who engaged in higher levels of lifetime strenuous PA and competitive sports prior to PD diagnosis experience slower motor and overall functional decline, suggesting that lifetime PA may contribute to a physical reserve advantageous for PD patients.

Claim reserving via inverse probability weighting: a micro-level Chain-Ladder method

Claim reserving via inverse probability weighting: a micro-level Chain-Ladder method

Effects of aircraft noise exposure on self-reported health through aircraft noise annoyance: Causal mediation analysis in the DEBATS longitudinal study in France.

Previous studies reported an association between transportation noise and self-reported health status (SRHS). They also suggested a mediating role of noise annoyance using conventional statistical methods. These methods are subject to bias in longitudinal studies with time-dependent exposure, mediator and confounding factors. This study aims to investigate the mediating role of aircraft noise annoyance in the effect of aircraft noise on SRHS using a causal inference approach to address time-dependent variables issues. We used data from 881 participants in all three visits in the DEBATS longitudinal study conducted around three French airports. Participants over 18 years of age reported their self-perceived health status, aircraft noise annoyance, and noise sensitivity by completing a questionnaire at three visits in 2013, 2015 and 2017. Noise maps were used to estimate aircraft noise levels outside their homes. Marginal structural models with inverse probability weighting were used to estimate the total effect of aircraft noise levels on SRHS and its decomposition into direct and indirect effect through aircraft noise annoyance. This study showed a deleterious effect of aircraft noise on SRHS. The odds ratio (OR) corresponding to the total effect and comparing the highest aircraft noise category (≥60 dBA) to the reference category (<50 dBA) was significant (ORpoor/fair_SHRS = 1.25 (95%CI: 1.06 to 2.08)). It also showed no direct effect of aircraft noise levels on SRHS, but an indirect effect through annoyance. This indirect effect increased as aircraft noise levels increased, with a statistically significant OR when comparing the highest noise category (≥60 dBA) to the lowest (<50 dBA) (ORpoor/fair_SHRS = 1.16 (95%CI: 1.03 to 1.52)). Nearly 66% of aircraft noise's effect on SRHS was mediated by aircraft noise annoyance. This study supports the deleterious causal effect of aircraft noise on SRHS. The results highlight the important mediating role of aircraft noise annoyance in the causal pathway from exposure to aircraft noise to poor/fair SRHS.

Investigating the causal relationship between wealth index and ICT skills: a mediation analysis approach

This study examines the relationship between the wealth index (WI) and Information and Communication Technology (ICT) skills among women aged 15–49 in Bangladesh. The research aims to establish a cause-and-effect relationship between WI and ICT skills, while also examining how education mediates this relationship. Using the data from the Bangladesh Multiple Indicator Cluster Survey (MICS) Program 2019, a two-stage stratified clustered sampling method yielded a sample of 64,378 women. The analysis employed inverse probability weighting (IPW) to assess the causal effect of WI on ICT skills while investigating the mediating role of education in this cause-and-effect relationship through causal mediation analysis. The findings demonstrate a significant relationship between higher economic status and increased ICT proficiency among women aged 15–49 in Bangladesh. Mediation analysis reveals education status as a significant mediator, indicating that educational attainment plays a vital role in linking wealth and ICT skills among women. Sensitivity analysis indicates the observed effect estimates are robust to unmeasured confounding. This research underscores the importance of economic empowerment and educational interventions in narrowing the digital divide and fostering ICT skills development among women, particularly in rural and economically disadvantaged communities.

The consumption of ultra-processed foods was associated with adiposity, but not with metabolic indicators in a prospective cohort study of Chilean preschool children

BackgroundIncreasing consumption of ultra-processed foods (UPF) has been identified as a risk factor for obesity and various diseases, primarily in adults. Nonetheless, research in children is limited, especially regarding longitudinal studies with metabolic outcomes. We aimed to evaluate the longitudinal association between consumption of UPF, adiposity, and metabolic indicators in Chilean preschool children.MethodsWe conducted a prospective analysis of 962 children enrolled in the Food and Environment Chilean Cohort (FECHIC). Dietary data were collected in 2016 at age 4 years with 24-h recalls. All reported foods and beverages were classified according to the NOVA food classification, and the usual consumption of UPF in calories and grams was estimated using the Multiple Source Method. Adiposity (z-score of body mass index [BMI z-score], waist circumference [WC], and fat mass [in kg and percentage]) and metabolic indicators (fasting glucose, insulin, HOMA-IR, triglycerides, total cholesterol, and cholesterol fractions) were measured in 2018, at the age of 6 years. Linear regression models ((0) crude, (1) adjusted for covariables, and (2) adjusted for covariables plus total caloric intake) were used to evaluate the association between UPF and outcomes. All models included inverse probability weights to account for the loss to the follow-up.ResultsAt 4 years, usual consumption of UPF represented 48% of the total calories and 39% of the total food and beverages grams. In models adjusted for covariables plus caloric intake, we found a positive association between UPF and BMI z-score (for 100 kcal and 100 g, respectively: b = 0.24 [95%CI 0.16–0.33]; b = 0.21 [95%CI 0.10–0.31]), WC in cm (b = 0.89 [95%CI 0.41–1.37]; b = 0.86 [95%CI 0.32–1.40]), log-fat mass in kg b = 0.06 [95%CI 0.03–0.09]; b = 0.04 [95%CI 0.01–0.07]), and log-percentage fat mass (b = 0.03 [95%CI 0.01–0.04]; b = 0.02 [95%CI 0.003–0.04]), but no association with metabolic indicators.ConclusionsIn this sample of Chilean preschoolers, we observed that higher consumption of UPF was associated with adiposity indicators 2 years later, but not with metabolic outcomes. Longer follow-up might help clarify the natural history of UPF consumption and metabolic risks in children.

Causal Inference of the Effect of Vaccination on COVID-19 Disease Severity and Need for Intensive Care Unit Admission Among Hospitalized Patients in an African Setting.

Background Coronavirus disease 2019 (COVID-19) is a novel, primarily respiratory, coronavirus that became a pandemic when it spread to over 210 countries and led to the death of over six million people. There is no definitive treatment for COVID-19, but vaccines have been developed that can help prevent severe illness and death. Studies have investigated the effect of vaccination on disease severity and outcome, and the findings indicate that vaccination is linked to a significant reduction in the risk of hospitalization, intensive care unit (ICU) admission, and disease mortality. However, there is a scarcity of evidence in Africa in general, and no similar study has been conducted in Ethiopia yet. Therefore, the study aimed to assess the effect of vaccination on COVID-19 disease severity and the need for ICU admission among hospitalized patients at a private specialty clinic in Ethiopia. Methods A retrospective cohort study was conducted among 126 patients with COVID-19, 41 vaccinated and 85 unvaccinated, who were hospitalized between September 2021 and May 2022. Data were summarized using frequency (percentage) and median (interquartile range (IQR)). To compare the characteristics of the two groups, Chi-square/Fisher's exact and Mann-Whitney U tests at p-values of ≤ 0.05 were used. To identify the effect of vaccination on COVID-19 disease severity, a marginal structural model (MSM) with an inverse probability weighting (IPW) approach using a robust Poisson regression model was fitted. Adjusted relative risk (ARR) and 95% confidence interval (CI) for ARR were used for interpreting the result. Results The cohort included groups that were comparable in terms of their sociodemographic and clinical characteristics. More than half of the participants were older than 60 years (n = 66, 52.4%), were males (n = 71, 56.3%), and had one or more comorbid illnesses (n = 66, 52.4%). At admission, 85 (67.5%) had severe disease, and 11 (8.7%) progressed after hospitalization and required ICU admission, of which three unvaccinated cases died. From the final model, vaccination was found to be associated with a 62% decreased risk of developing severe COVID-19 disease if infected, compared to not getting vaccinated (ARR = 0.38, 95% CI = 0.23-0.65, p < 0.0001). Conclusions The study's findings support previous reports that vaccinated people are less likely to develop severe COVID-19 disease if later infected with the virus, emphasizing the importance of continuing efforts to promote COVID-19 vaccination not only to safeguard individuals but also to confer community-level immunity.

Frailty index is an independent predictor of all-cause and cardiovascular mortality in Eastern Europe: a multicentre cohort study

BackgroundThis study investigates the association between frailty and mortality in Eastern European populations, which remains largely unexplored compared with Western Europe. The aim is to assess the risk of all-cause...

Preoperative Atelectasis in Patients with Obesity Undergoing Bariatric Surgery: A Cross-Sectional Study.

Pulmonary atelectasis is present even before surgery in patients with obesity. We aimed to estimate the prevalence and extension of preoperative atelectasis in patients with obesity undergoing bariatric surgery and to determine if variation in preoperative Spo2 values in the seated position at room air is explained by the extent of atelectasis coverage in the supine position. This was a cross-sectional study in a single center specialized in laparoscopic bariatric surgery. Preoperative chest computed tomographies were reassessed by a senior radiologist to quantify the extent of atelectasis coverage as a percentage of total lung volume. Patients were classified as having atelectasis when the affection was ≥2.5%, to estimate the prevalence of atelectasis. Crude and adjusted prevalence ratios (aPRs) and odds ratios (aORs) were obtained to assess the relative prevalence of atelectasis and percentage coverage, respectively, with increasing obesity category. Inverse probability weighting was used to assess the total, direct (not mediated), and indirect (mediated through atelectasis) effects of body mass index (BMI) on preoperative Spo2, and to quantify the magnitude of mediation (proportion mediated). E-values were calculated, to represent the minimum magnitude of association that an unmeasured confounder with the same directionality of the effect should have to drive the observed point estimates or lower confidence intervals (CIs) to 1, respectively. In 236 patients with a median BMI of 40.3 kg/m2 (interquartile range [IQR], 34.6-46.0, range: 30.0-77.3), the overall prevalence of atelectasis was 32.6% (95% CI, 27.0-38.9) and by BMI category: 30 to 35 kg/m2, 12.7% (95% CI, 6.1-24.4); 35 to 40 kg/m2, 28.3% (95% CI, 17.2-42.6); 40 to 45 kg/m2, 12.3% (95% CI, 5.5-24.3); 45 to 50 kg/m2, 48.4% (95% CI, 30.6-66.6); and ≥50 units, 100% (95% CI, 86.7-100). Compared to the 30 to 35 kg/m2 group, only the categories with BMI ≥45 kg/m2 had significantly higher relative prevalence of atelectasis-45 to 50 kg/m2, aPR = 3.52 (95% CI, 1.63-7.61, E-value lower bound: 2.64) and ≥50 kg/m2, aPR = 8.0 (95% CI, 4.22-15.2, E-value lower bound: 7.91)-and higher odds of greater atelectasis percentage coverage: 45-50 kg/m2, aOR = 7.5 (95% CI, 2.7-20.9) and ≥50 kg/m2, aOR = 91.5 (95% CI, 30.0-279.3). Atelectasis percent alone explained 70.2% of the variation in preoperative Spo2. The proportion of the effect of BMI on preoperative Spo2 values <96% mediated through atelectasis was 81.5% (95% CI, 56.0-100). The prevalence and extension of atelectasis increased with higher BMI, being significantly higher at BMI ≥45 kg/m2. Preoperative atelectasis mediated the effect of BMI on Spo2 at room air in the seated position.

Outcome of patients with large B-cell lymphoma treated with tafasitamab plus lenalidomide either before or after CAR T-cell therapy

AbstractTafasitamab plus lenalidomide (TAFA-LEN) treatment relevance pre- or post-anti-CD19 chimeric antigen receptor (CAR) T-cell therapy is debated. We analyzed patients with large B-cell lymphoma in the DESCAR-T registry treated with axi[1]cel or tisa-cel in ≥3rd line and TAFA-LEN before (n = 15, “TL-pre-CAR-T” set) or directly after (n = 52, “TL-post-CAR-T” set) CAR T-cell therapy. We compared TAFA-LEN v. other treatments using inverse probability weighting in the TL-post-CAR[1]T set. In the TL-post-CAR-T set, the median progression-free survival (mPFS), overall survival (mOS), and duration of response (mDOR) since the first treatment for progression (mPFS2/mOS2/mDOR2) were 3, 4.7, and 8.1 months, respectively. The best overall response rate (bORR) and best complete response rate (bCRR) after TAFA-LEN were 13.5% and 7.7%, respectively. Outcomes were better for patients who relapsed >6 months after CAR T-cell therapy (mPFS2: 5.6 vs 2 months, P = .0138; mOS2: not reached vs 3.8 months, P = .0034). The bORR and bCRR between TAFA-LEN and other treatments were 20.6% vs 24.9% and 11.6% vs 15.6%, respectively. Outcomes were similar between TAFA-LEN and other treatments (mPFS2: 2.9 vs 2.4 months, P = .91; mOS2: 3.3 vs 5.5 months, P = .06). In an exploratory analysis of the TL-pre-CAR-T set, the median TAFA-LEN treatment duration before CAR-T was 3.7 months with no patient becoming CD19 negative. The bORR, bCRR, 6- month PFS, and OS rates after CAR T-cell infusion were 45.5%, 36.4%, 20.1%, and 58.2%, respectively. Neither TAFA-LEN nor comparative salvage treatment improved outcomes for patients relapsing after CAR T-cell therapy.

An introduction to inverse probability weighting and marginal structural models: The case of environmental tobacco exposure and attention deficit/hyperactivity disorder behaviors.

Developmental scientists routinely examine how a focal predictor relates to some aspect of children's development. Although covariate adjustment is typically used to test hypotheses, propensity score-based methods, including inverse probability of treatment weighting (IPTW) and marginal structural models (MSM), can strengthen inference and answer more nuanced, developmentally relevant questions. This article provides a didactic introduction to IPTW and MSM methods and demonstrates their use for testing the impact of environmental smoke exposure (continuous treatment) from 6 to 90 months on parent-reported attention deficit hyperactivity disorder behaviors in first grade for 1,053 children (51% male, 44% Black) in the Family Life Project. We highlight differences that result both in conclusions and in the evaluation of assumptions for IPTW and MSM relative to more traditional covariate adjustment methods. Sample Stata syntax is provided. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Impact of Quitline Services on Tobacco Cessation: An Application of Modern Epidemiological Methods.

This study investigated the effectiveness of quitline service intensity (high vs. low) on past 30-day tobacco abstinence at 7-months follow-up, using observational data from the Oklahoma Tobacco Helpline (OTH) between April 2020 and December 2021. To assess the impact of loss to follow-up and non-random treatment assignment, we fit the parameters of a marginal structural model to estimate inverse probability weights for censoring (IPCW) and treatment (IPTW) and combined (IPCTW). The Risk Ratio (RR) was estimated using modified Poisson regression with robust variance estimator. Of the 4,695 individuals included in the study, 64% received high-intensity cessation services, and 53% were lost to follow-up. Using the conventional complete case analysis (responders only), high-intensity cessation services were associated with abstinence (RR=1.18; 95 CI: 1.04, 1.34). The effect estimate was attenuated after accounting for censoring (RR=1.14; 95% CI: 1.00, 1.30). After adjusting for both baseline confounding and selection bias via IPTCW, high-intensity cessation services were associated with 1.23 times (95% CI: 1.08, 1.41) the probability of abstinence compared to low-intensity services. Despite relatively high loss to follow-up, accounting for selection bias and confounding did not notably impact quit rates or the relationship between intensity of quitline services and tobacco cessation among OTH participants.

Chemotherapy affects the development of pathological scarring after general thoracic surgery in children.

Globally, a great number of children have been suffering from physical dysfunction and psychological stress due to uncontrollable scar growth and a lack of effective modalities. Despite chemotherapy's established role as a primary treatment for pathological scarring in adults, its efficacy in preventing or minimizing scar formation in paediatric patients remains underexplored. This retrospective cohort study aimed to refine the relevant clinical evidence and investigate the effect of chemotherapy on pathological scars in children. In this single-centre retrospective cohort study, the data of children aged ≤18 years who underwent thoracic surgery at the Children's Hospital of Fudan University between 1 January 2018, and 31 December 2021 were assessed. The primary outcome was pathological scarring, and the secondary outcomes were subjective symptoms accompanying pathological scarring, such as pain and itching. To mitigate indication bias, analysis was performed by inverse probability weighting (IPTW) log-binomial regression models. The cohort comprised 102 children, among whom 36 received adjuvant chemotherapy perioperatively, while 66 did not. Under the IPTW model, a statistically significant difference in pathological scarring incidence was observed between the chemotherapy and non-chemotherapy groups (16.7% vs. 29.4%, p = 0.027). And the children received chemotherapy post-operatively had a lower relative risk of pathological scarring, compared with those received chemotherapy both before and after surgery (19.8% vs. 28.8%). Adjuvant chemotherapy treatment after surgery may reduce the incidence of post-operative pathological scarring in children.

Inverse Probability Weighting to Estimate Impacts of Hypothetical Occupational Limits on Radon Exposure to Reduce Lung Cancer.

Radon is a known cause of lung cancer. Protective standards for radon exposure are derived largely from studies of working populations that are prone to healthy worker survivor bias. This bias can lead to under-protection of workers and is a key barrier to understanding health effects of many exposures. We apply inverse probability weighting to study a set of hypothetical exposure limits among 4,137 male, White and American Indian radon-exposed uranium miners in the Colorado Plateau followed from 1950 to 2005. We estimate cumulative risk of lung cancer through age 90 under hypothetical occupational limits. We estimate that earlier implementation of the current US Mining Safety and Health Administration annual standard of 4 working level months (implemented here as a monthly exposure limit) could have reduced lung cancer mortality from 16/100 workers to 6/100 workers (95% confidence intervals: 3/100, 8/100), in contrast with previous estimates of 10/100 workers. Our estimate is similar to that among contemporaneous occupational cohorts. Inverse probability weighting is a simple and computationally efficient way address healthy worker survivor bias in order to contrast health effects of exposure limits and estimate the number of excess health outcomes under exposure limits at work.

Association of Kidney Function with Sodium-Glucose Co-Transporter 2 Inhibitor Discontinuation among US Veterans.

The impact of sodium-glucose co-transporter-2 inhibitors (SGLT2i) on cardiovascular disease and chronic kidney disease (CKD) may be limited if discontinued in persons with CKD. We sought to determine whether CKD at SGLT2i initiation was associated with subsequent discontinuation. This cohort study used electronic health record data of patients who initiated SGLT2i in the Veterans Health Administration from January 2017 through December 2021. The primary exposure was eGFR category at the time of SGLT2i initiation. The risk of SGLT2i discontinuation, defined by a provider order or expiration of an SGLT2i prescription without resumption in the following 180 days, was estimated using proportional hazards models with inverse probability weights for censoring due to death. Analyses were stratified by year of SGLT2i initiation. Among the 222,772 patients initiating an SGLT2i during the study period, median age was 68 (IQR: 60-73) years, 95% were male, and median (IQR) eGFR was 73 (58, 89) mL/min/1.73m2. Median follow-up was 1.6 years; 32% experienced SGLT2i discontinuation. Cumulative risk of discontinuation at one year was 21% to 27% across calendar years; approximately 41% of these discontinuations occurred within the first three months. There was a graded association between lower baseline eGFR and greater risk of discontinuation; this association attenuated across calendar years. Those initiating an SGLT2i in 2017 with baseline eGFR of 45-59 and 30-44 had 1.34- (95%CI: 1.21-1.49) and 2.04-fold (95%CI: 1.58-2.63) risks of discontinuation, respectively, compared to those with eGFR ≥60 ml/min/1.73m2. These hazard ratios reduced to 1.05 (95%CI: 1.02-1.10) and 1.20 (95%CI: 1.14-1.26), respectively, in those initiated in 2021. A substantial proportion of patients experience SGLT2i discontinuation within a year of initiation. Persons with lower eGFR had higher discontinuation rates; however, this trend attenuated over time. Additional studies identifying determining factors of discontinuation are needed to fully realize the benefits of SGLT2i.