Inverse Probability Weighting Research Articles

How did the ‘whistle-to-whistle’ ban affect gambling advertising on TV? A live football matching study

Background In 2019, the gambling industry introduced a voluntary partial advertising ban during live sports broadcasts in the United Kingdom known as the ‘whistle-to-whistle’ ban. This study explores the change in television advertising around live football games following the introduction of this ban. Methods Inverse Probability Weighted (IPW) matching models identified the change in the frequency of advertising associated with the implementation of restrictions in each section, and across the entire duration, of a live football game. Data on UK television schedules (Concise Media, TVSportsGuide) and gambling advertising (Nielsen Media) covered 3 months (1st September to 1st December) pre (2018), and post-ban (2019). There were 1049 live football games across the period studied: 468 in 2018 and 581 in 2019. Results The implementation of the ban was associated with a reduction in advertising (2.3 advertisements per-programme (p < 0.001, CI [−2.75, −1.84])), driven predominantly by reductions during half-time (2.18 advertisements per-programme (p < 0.001, CI [−2.32, −2.04])). It was associated with an increase in advertisements (0.34 advertisements per-programme (p < 0.001, CI [0.09,0.59])) during the pre-match section. In the post-ban period, an average of 3 (SD: 3.5) advertisements per-programme remained. Conclusions A voluntary partial gambling advertising ban in the UK was associated with reductions in television advertising during live football games during the restricted period. There is evidence of increased advertising in the unrestricted period due to the partial nature of the ban. Future research is needed to explore the impact of the ban on other types of advertising, and across other channels.

Xin-yi-san contains potent human CYP1A2 inhibitors and its combined use with theophylline in treatment increases adverse risks in patients

BackgroundThe Xin-yi-san herbal decoction (XYS) is commonly used to treat patients with allergic rhinitis in Taiwan. Theophylline is primarily oxidized with high affinity by human cytochrome P450 (CYP)1A2, and has a narrow therapeutic index. PurposeThis study aimed to investigate the inhibition of human CYP1A2-catalyzed theophylline oxidation (THO) by XYS and its adverse effects in patients. MethodsHuman CYPs were studied in recombinant enzyme systems. The influence of concurrent XYS usage in theophylline-treated patients was retrospectively analyzed. ResultsAmong the major human hepatic and respiratory CYPs, XYS inhibitors preferentially inhibited CYP1A2 activity, which determined the elimination and side effects of theophylline. Among the herbal components of XYS decoction, Angelicae Dahuricae Radix contained potent THO inhibitors. Furanocoumarin imperatorin was abundant in XYS and Angelicae Dahuricae Radix decoctions, and non-competitively inhibited THO activity with Ki values of 77‒84 nM, higher than those (20‒52 nM) of fluvoxamine, which clinically interacted with theophylline. Compared with imperatorin, the intestinal bacterial metabolite xanthotoxol caused weaker THO inhibition. Consistent with the potency of the inhibitory effects, the docking analysis generated Gold fitness values in the order−fluvoxamine > imperatorin > xanthotoxol. During 2017‒2018, 2.6 % of 201,093 theophylline users consumed XYS. After inverse probability weighting, XYS users had a higher occurrence of undesired effects than non-XYS users; in particular, there was an approximately two-fold higher occurrence of headaches (odds ratio (OR), 2.14; 95 % confidence interval (CI), 1.99‒2.30; p < 0.001) and tachycardia (OR, 1.83; 95 % CI, 1.21‒2.77; p < 0.05). The incidence of irregular heartbeats increased (OR, 1.36; 95 % CI, 1.07‒1.72; p < 0.05) only in the theophylline users who took a high cumulative dose (≥ 24 g) of XYS. However, the mortality in theophylline users concurrently taking XYS was lower than that in non-XYS users (OR, 0.24; 95 % CI, 0.14‒0.40; p < 0.001). ConclusionXYS contains human CYP1A2 inhibitors, and undesirable effects were observed in patients receiving both theophylline and XYS. Further human studies are essential to reduce mortality and to adjust the dosage of theophylline in XYS users.

Laparotomy for Traumatic Splenic Injury: Should we Increase our Efforts to Preserve the Spleen?

Abstract Background In trauma laparotomy the spleen is removed very liberally, and often little effort is made for splenic preservation. Aims The aim of this study was to assess the effect of surgical management (splenic repair vs. splenectomy) on outcomes in patients undergoing trauma laparotomy. Methods This is a trauma registry (TQIP) study (2013–2019), including adult patients with severe splenic injuries (grades III-V) undergoing trauma laparotomy. Characteristics and outcomes of patients who underwent splenic repair vs. splenectomy within 6 hours of admission were compared using different statistical approaches, i.e. 1:1 exact matching with consecutive conditional logistic regression analysis as primary analysis, multivariable logistic regression, propensity score matching and inverse-probability weighting as sensitivity analyses. The primary outcome was in-hospital mortality. Results A total of 11,247 patients with a severe splenic injury undergoing trauma laparotomy within 6 hours of admission were identified. Of these, 10,820 (96.2%) patients underwent splenectomy and 427 (3.8%) patients splenic repair within 6 hours of admission. Among patients who underwent an initial splenic salvage procedure, 23 (5.3%) patients underwent a splenectomy during the subsequent hospital stay. 400 patients with splenic preservation, were matched with 400 patients who underwent splenectomy (matched for age, sex, hypotension, trauma mechanism as well as AIS spleen grades 3,4,5 and AIS groups (AIS 0-2, AIS 3, AIS 4-5) for head, face, neck, thorax, spine, and lower &amp; upper extremity). The mortality was significantly lower in the group of patients with splenic repair (6.5% vs 12.8%, p=0.002). The mortality benefit was subsequently verified by conditional regression analysis (aOR 0.4, CI 95% 0.2; 0.9). Multivariable logistic regression, propensity score matching, and inverse-probability weighting confirmed the lower mortality in the splenic repair group. Conclusion In trauma laparotomy splenic repair was independently associated with lower mortality compared with splenectomy. Splenectomy was required in approximately 5% of the patients after initial splenic repair. The findings provide evidence that efforts for spleen preservation in trauma laparotomy should be considered in selected cases.

A doubly robust estimator for the Mann Whitney Wilcoxon rank sum test when applied for causal inference in observational studies

ABSTRACT The Mann–Whitney–Wilcoxon rank sum test (MWWRST) is a widely used method for comparing two treatment groups in randomized control trials, particularly when dealing with highly skewed data. However, when applied to observational study data, the MWWRST often yields invalid results for causal inference. To address this limitation, Wu et al. (Causal inference for Mann–Whitney–Wilcoxon rank sum and other nonparametric statistics, Stat. Med. 33 (2014), pp. 1261–1271) introduced an approach that incorporates inverse probability weighting (IPW) into this rank-based statistic to mitigate confounding effects. Subsequently, Mao (On causal estimation using U-statistics, Biometrika 105 (2018), pp. 215–220), Zhang et al. (Estimating Mann Whitney-type causal effects, J. Causal Inference 7 (2019), ARTICLE ID 20180010), and Ai et al. (A Mann–Whitney test of distributional effects in a multivalued treatment, J. Stat. Plan. Inference 209 (2020), pp. 85–100) extended this IPW estimator to develop doubly robust estimators. Nevertheless, each of these approaches has notable limitations. Mao's method imposes stringent assumptions that may not align with real-world study data. Zhang et al.'s (Estimating Mann Whitney-type causal effects, J. Causal Inference 7 (2019), ARTICLE ID 20180010) estimators rely on bootstrap inference, which suffers from computational inefficiency and lacks known asymptotic properties. Meanwhile, Ai et al. (A Mann–Whitney test of distributional effects in a multivalued treatment, J. Stat. Plan. Inference 209 (2020), pp. 85–100) primarily focus on testing the null hypothesis of equal distributions between two groups, which is a more stringent assumption that may not be well-suited to the primary practical application of MWWRST. In this paper, we aim to address these limitations by leveraging functional response models (FRM) to develop doubly robust estimators. We demonstrate the performance of our proposed approach using both simulated and real study data.

The interplay between ADHD and school shift on educational outcomes in children and adolescents: A cross-sectional and longitudinal analysis.

Many countries implement a double-shift schooling system, offering morning or afternoon shifts, driven by diverse factors. Young people with ADHD may face educational problems attending morning shifts compared to afternoon shifts. To investigate this, we used data from a Brazilian school-based cohort (n = 2.240, 6-14 years old, 45.6% female; 50.2% in the morning shift; 11.2% with ADHD). ADHD was determined by child psychiatrists using semi-structured interview. Educational outcomes were measured cross-sectionally and three years later (80% retention) and included reading and writing ability, performance in school subjects, and any negative school events (repetition, suspension, or dropout). Generalized regression models tested the interaction between ADHD and school shift and were adjusted for age, sex, race/ethnicity, intelligence, parental education, socioeconomic status, and site. Attrition was adjusted with inverse probability weights. We used two dimensional measures of attentional problems as sensitivity analysis. ADHD and morning shift were independently associated with lower reading and writing ability and with higher odds for negative school events cross sectionally. ADHD independently predicted lower performance in school subjects and higher negative school events at follow-up. Interaction was found only at the cross-sectional level in a way that those studying in the afternoon present better educational outcomes compared with those studying in the morning only if they have lower ADHD symptom. Thus, ADHD was not associated with poorer educational outcomes among those studying in the morning. However, participants studying in the afternoon with lower levels of attentional problems presented better educational, despite these associations fade away over time.

Long-Term Results After Laparoscopic Lavage for Perforated Diverticulitis Purulent Peritonitis in Sweden: A Population-Based Observational Study.

To compare long-term outcomes after laparoscopic lavage with resection surgery for perforated diverticulitis, Hinchey grade III as practiced in Sweden for 3 years. Laparoscopic lavage has been studied in 3 randomized controlled trials. Long-term results indicate that additional surgery and a remaining stoma are less common after lavage compared with resection, but data from routine care and larger cohorts are needed to get a more complete picture. LapLav is a national cohort study with nearly complete coverage of all patients operated in Sweden between 2016 and 2018. The cohort was retrieved from the national patient register by a definition based on the Classification of Diseases and Related Health Problems-10 code plus the surgical procedural code. All medical records have been reviewed and data retrieved in addition to registry data. Propensity score with inverse probability weighting was used to balance the 2 groups, that is, laparoscopic lavage vs resection surgery. Before the propensity score was applied, the cohort consisted of 499 patients. Additional surgery was more common in the resection group [odds ratio, 0.714; 95% confidence interval (CI) = 0.529-0.962; P = 0.0271]. Mortality did not differ between the groups (hazard ratio, 1.20; 95% CI = 0.69-2.07; P = 0.516). In the lavage group, 27% of patients went on to have resection surgery. In Swedish routine care, laparoscopic lavage was feasible and safe for the surgical treatment of perforated diverticulitis, Hinchey grade III. Our results indicate that laparoscopic lavage can be used as a first-choice treatment.

In-hospital and readmission outcomes of patients with cancer admitted for pulmonary embolism treated with or without catheter-based therapy

BackgroundCancer patients are at risk of pulmonary embolism (PE). Catheter-based therapies (CBT) are novel reperfusion options for PE though data in patients with cancer is lacking. Study design and methodsPatients with intermediate- or high-risk PE were identified using the National Readmission Database (NRD) from 2017 to 2020. Primary outcome were in-hospital death and 90-day readmission. Secondary outcomes were in-hospital bleeding, 90-day readmission for venous thromboembolism (VTE)-related or right heart failure-related reasons and bleeding. Propensity scores were estimated using logistic regression and inverse-probability treatment weighting (IPTW) was utilized to compare outcomes between CBT and no CBT as well as CBT versus systemic thrombolysis. ResultsA total of 7785 patients were included (2511 with high-risk PE) of whom 1045 (13.4%) were managed with CBT. After IPTW, CBT was associated with lower rates of index hospitalization death (OR 0.89, 95% CI 0.83–0.96) and 90-day readmission (HR 0.75, 95% CI 0.69–0.81) but higher rates of in-hospital bleeding (OR 1.11, 95% CI 1.03–1.20) which was predominantly post-procedural bleeding. CBT was associated with lower risk of major bleeding (20.8% vs 24.8%; OR 0.80, 95% CI 0.68–0.94) compared with systemic thrombolysis. InterpretationAmong patients with cancer with intermediate or high-risk PE, CBT was associated with lower in-hospital death and 90-day readmission. CBT was also associated with decreased risk of index hospitalization major bleeding compared with systemic thrombolysis. Prospective, randomized trials with inclusion of patients with cancer are needed to confirm these findings.

Banking for the Culture: Black-owned banks as cultural assets during the subprime lending boom

Today, black-owned banks are important financial resources challenging economic exclusion. Nevertheless, they do not associate strongly with building black wealth. Some scholars argue this signals black-owned banks are ornamental, or ineffective responses to legacies of economic exclusion in black segregated neighborhoods. To engage these critiques, I draw on the dialectical theoretical frames of cultural assets and structural deficits to examine the effectiveness of black-owned banks during the subprime lending boom—a period when bank practices exploiting a history of economic exclusion in black segregated neighborhoods intensify. Specifically, I analyze administrative data from the Federal Deposit Insurance Corporation (FDIC) and the Home Mortgage Disclosure Act (HMDA) to assess whether black-owned banks associate with access to mortgage credit when the subprime lending boom peaks in 2006. Using propensity score matching with inverse probability weighting, I find black-owned banks do not associate with mortgage originations in 2006; but neighborhoods with black-owned banks receive fewer subprime mortgage loans, compared to matched ones without them. As such, black-owned banks appear to effectively shield black segregated neighborhoods from the time period's predation. Overall, findings imply black-owned banks support protective credit markets during periods of intensifying economic exclusion and exploitation.

Parameter Estimation in Spatial Autoregressive Models with Missing Data and Measurement Errors

This study addresses the problem of parameter estimation in spatial autoregressive models with missing data and measurement errors in covariates. Specifically, a corrected likelihood estimation approach is employed to rectify the bias in the log-maximum likelihood function induced by measurement errors. Additionally, a combination of inverse probability weighting (IPW) and mean imputation is utilized to mitigate the bias caused by missing data. Under several mild conditions, it is demonstrated that the proposed estimators are consistent and possess oracle properties. The efficacy of the proposed parameter estimation process is assessed through Monte Carlo simulation studies. Finally, the applicability of the proposed method is further substantiated using the Boston Housing Dataset.

Effect of immediate initiation of invasive ventilation on mortality in acute hypoxemic respiratory failure: a target trial emulation

PurposeInvasive ventilation is a fundamental treatment in intensive care but its precise timing is difficult to determine. This study aims at assessing the effect of initiating invasive ventilation versus waiting, in patients with hypoxemic respiratory failure without immediate reason for intubation on one-year mortality.MethodsEmulation of a target trial to estimate the benefit of immediately initiating invasive ventilation in hypoxemic respiratory failure, versus waiting, among patients within the first 48-h of hypoxemia. The eligible population included non-intubated patients with SpO2/FiO2 ≤ 200 and SpO2 ≤ 97%. The target trial was emulated using a single-center database (MIMIC-IV) which contains granular information about clinical status. The hourly probability to receive mechanical ventilation was continuously estimated. The hazard ratios for the primary outcome, one-year mortality, and the secondary outcome, 30-day mortality, were estimated using weighted Cox models with stabilized inverse probability weights used to adjust for measured confounding.Results2996 Patients fulfilled the inclusion criteria of whom 792 were intubated within 48 h. Among the non-invasive support devices, the use of oxygen through facemask was the most common (75%). Compared to patients with the same probability of intubation but who were not intubated, intubation decreased the hazard of dying for the first year after ICU admission HR 0.81 (95% CI 0.68–0.96, p = 0.018). Intubation was associated with a 30-day mortality HR of 0.80 (95% CI 0.64–0.99, p = 0.046).ConclusionThe initiation of mechanical ventilation in patients with acute hypoxemic respiratory failure reduced the hazard of dying in this emulation of a target trial.

Health-related quality of life and impact of socioeconomic status among primary and secondary school students after the third COVID-19 wave in Berlin, Germany.

In the earlier phases of the COVID-19 pandemic, studies in Germany and elsewhere found an overall reduction in health-related quality of life (HRQoL) among students. However, there is little evidence on later pandemic stages as well as socioeconomic influencing factors. We aimed to (1) describe HRQoL in a Berlin student cohort at two time points in mid-2021, and to (2) analyze the effects of household income and education. We assessed HRQoL of students from 24 randomly selected primary and secondary schools in Berlin, Germany, with the KIDSCREEN-10 index in June and September 2021. To adjust for non-response bias, inverse probability weighting was applied. The potential effects of both household income and education (lower vs. higher) were estimated in generalized linear mixed models, based on prior assumptions presented in directed acyclic graphs. Our cohort comprised 660 students aged 7-19 years. In June 2021, 11.3% [95% CI = 9.0% - 14.0%] reported low HRQoL, whereas in September 2021, this increased to 13.7% [95% CI = 11.1% - 16.5%], with adolescent girls more frequently reporting low HRQoL at both time points (20% [95% CI = 17.1% - 23.3%] and 29% [95% CI = 25.5% - 32.5%]) compared to boys and younger children. While there was no statistically significant total effect of lower household income on HRQoL, a negative effect of lower household education was statistically significant (β = -2.15, SE 0.95, 95% CI = -4.01 to -0.29, p = 0.024). In summary, students' HRQoL in mid-2021 was better than that documented in other studies conducted at pandemic onset using KIDSCREEN-10. Female adolescents reported low HRQoL more often, and lower household education significantly reduced children's HRQoL. Support strategies for psychosocial wellbeing should consider socioeconomically disadvantaged children as important target groups.

Effectiveness and safety of half-dose thrombolysis in intermediate-high risk pulmonary embolism: a single centre experience

Abstract Funding Acknowledgements None. Introduction According to current guidelines, full-dose systemic thrombolysis for pulmonary embolism (PE) is limited to patients either classified as high risk or presenting intermediate risk with hemodynamically instability. As evidenced by recent clinical trials, "low" half-dose (50 mg) tissue plasminogen activator (HDrtPA) appears to offer a safe, effective alternative with a low bleeding risk, especially if catheter directed therapies are not available. Purpose we aimed to evaluate if HDrtPA in intermediate-high risk PE could improve right ventricular (RV)-arterial coupling by means of TAPSE/PAPs ratio, right ventricular basal dimensions in 4 chambers (RVD1), and tricuspid velocity (TV) between admission and discharge, exploring eventual associated bleeding risk. Methods we retrospectively analized 90 intermediate-high risk PE patients consecutively admitted to our intensive cardiac care unit between January 2016 and May 2023. Diagnosis was achieved by computed tomography in all cases. All patients underwent echocardiographic assessment upon admission and at discharge along with baseline lab values. HDrtPA patients (Group A, n=28) received low-dose thrombolytic therapy (0,6 mg/kg maximum 50 mg in 1 hour) combined with unfractionated heparin. Standard anticoagulation patients (Group B) included patients exclusively treated with parenteral anticoagulants. Primary endpoint was echocardiographic improvement of RV-arterial coupling (TAPSE/PAPS), and of pulmonary pressures (tricuspid velocity, TV) and right ventricular basal dimension (RVD1) between admission and dis-charge in the two treatment arms. To perform this analysis, linear regression models with Inverse Probability Weighting (IPW) propensity scores were used. Secondary endpoint was presence of mayor or minor bleeding between groups, and a descriptive analysis of mortality due to paucity of events. Results in the whole population mean age was 73.48 ± 12.49 (mean ± sd) and n=43 (47.8%) were males. Between admission and discharge, group A (HDrtPA) had an improvement of TAPSE/PAPs (+0.16, p=0.05, CI 95%: -0.002; 0.325), of RVD1 (-6.00 mm, p &amp;lt;0.01, CI 95%: -2.59; 9.41). Reduction of TV values (-0.45 m/s, p=0.108, CI 95%: -1.02; 0.10) was not statistically significant at IPW propensity score, but deserves further investigations. No significant increase of major bleedings were recorded between two groups (Group A: 1/28 3.5%, Group B: 0/52 0%) with an acceptable number of minor, non fatal bleedings (Group A: 7/28: 25%, Group B 1/62 1.6%). Death occurred in 3 patients in group A (10%) and 1 patient in group B (1.6%). Conclusion half dose of tissue plasminogen activator (HDrtPA) offer a promising alternative to anticoagulation alone therapy in selected patients with high-intermediate risk pulmonary embolism. In our experience, this approach seems to acutely improve RV-arterial coupling and right ventricular dimensions, without an increase of major bleeding risk.

Towards optimal model evaluation: enhancing active testing with actively improved estimators

With rapid advancements in machine learning and statistical models, ensuring the reliability of these models through accurate evaluation has become imperative. Traditional evaluation methods often rely on fully labeled test data, a requirement that is becoming increasingly impractical due to the growing size of datasets. In this work, we address this issue by extending existing work on active testing (AT) methods which are designed to sequentially sample and label data for evaluating pre-trained models. We propose two novel estimators: the Actively Improved Levelled Unbiased Risk (AILUR) and the Actively Improved Inverse Probability Weighting (AIIPW) estimators which are derived from nonparametric smoothing estimation. In addition, a model recalibration process is designed for the AIIPW estimator to optimize the sampling probability within the AT framework. We evaluate the proposed estimators on four real-world datasets and demonstrate that they consistently outperform existing AT methods. Our study also shows that the proposed methods are robust to changes in subsample sizes, and effective at reducing labeling costs.

Antidepressant exposure and long-term dementia risk in a nationwide retrospective study on US veterans with midlife major depressive disorder.

The use of antidepressants in major depressive disorder (MDD) has been reported to influence long-term risk of Alzheimer's disease (AD) and AD-related dementias (AD/ADRD), but studies are conflicting. We used inverse probability weighted (IPW) Cox models with time-varying covariates in a retrospective cohort study among midlife veterans with MDD within the US Veterans Affairs healthcare system from January 1, 2000 to June 1, 2022. A total of 35,200 patients with MDD were identified. No associations were seen regarding the effect of being exposed to any antidepressant versus no exposure on AD/ADRD risk (events=1,056, hazard ratio=0.94, 95% confidence interval: 0.81 to 1.09) or the exposure to specific antidepressant classes versus no exposure. A risk reduction was observed for female patients in a stratified analysis; however, the number of cases was small. Our study suggests that antidepressant exposure has no effect on AD/ADRD risk. The association in female patients should be interpreted with caution and requires further attention. We studied whether antidepressant use was associated with future dementia risk. We specifically focused on patients after their first-ever diagnosis of depression. We used IPW Cox models with time-varying covariates and a large observation window. Our study did not identify an effect of antidepressant use on dementia risk. A risk reduction was observed in female patients, but the number of cases was small.

Long-term oral administration of Huaier granules improves survival outcomes in hepatocellular carcinoma patients within Milan criteria following microwave ablation: a propensity score matching and stabilized inverse probability weighting analysis.

This study aimed to elucidate the therapeutic effects of Huaier granules on hepatocellular carcinoma (HCC) within the Milan criteria in patients who underwent microwave ablation (MWA). A total of 228 patients were included, with 97 in the Huaier group and 131 in the control group. We evaluated progression-free survival (PFS), overall survival (OS), and extrahepatic metastasis survival (EMS) using Kaplan-Meier (KM) curves with a log-rank test. Propensity Score Matching (PSM) and Stabilized Inverse Probability of Treatment Weighting (IPTW) were performed to minimize selection and confounding biases. Following PSM, the 1-, 3-, and 5-year PFS rates in the Huaier and control groups were 83.5% vs 70.7%, 57.7% vs 42.6%, and 43.6% vs 31.9% (p = 0.030), respectively. The 1-, 3-, and 5-year OS rates were 98.9% vs 95.6%, 83.9% vs 72.3%, and 72.2% vs 53.7% (p = 0.023), respectively. The corresponding 1-, 3-, and 5-year EMS rates were 98.9% vs 93.4%, 91.7% vs 83.7%, and 91.7% vs 78.5% (p = 0.039), respectively. Stabilized IPTW analysis of KM curves yielded results similar to those of the PSM analysis. Additionally, administering Huaier granules for at least 6 months significantly improved PFS and OS. Huaier granules can reduce the risk of recurrence and improve the OS of patients with HCC within the Milan criteria following MWA. Administering Huaier granules for over 6 months proved beneficial.

Estimation of the causal effect of sex on neonatal intensive care unit outcomes among very low birth weight infants.

Estimate the causal effect of sex on outcomes in the neonatal intensive care unit (NICU) among very low birth weight (VLBW) infants. Retrospective cohort study using Vermont Oxford Network data to compare NICU outcomes for VLBW males versus females. Odds ratios (OR) for outcomes that differed significantly by sex were computed using standard unweighted analysis and inverse probability weighted (IPW) analysis to correct for selection bias. Using standard analysis, males were significantly more likely to die before discharge and experience six other adverse outcomes. From IPW analysis, male sex caused a 56% increase in the odds of death before discharge (OR = 1.56, 95% confidence interval: 1.18-1.94). Standard unweighted results were significantly biased towards increased risk of adverse outcomes for males (p = 0.005) compared to IPW results for which three outcomes were no longer significantly associated with male sex. Standard statistical methods generally overestimate the casual effect of sex among VLBW infants.

Incremental Healthcare Costs of Diabetes Mellitus in a Middle-Income Country Using Administrative Healthcare Data

ObjectivesTo estimate the incremental medical cost of diabetes mellitus using information from administrative databases in Colombia. MethodsWe carried out a retrospective cohort study with administrative health databases from Colombian population affiliated in the contributory health insurance scheme. We used an operative definition to select the cohort with diabetes. Incremental cost and cost ratio of diabetes were estimated using an inverse probability weighting of treatment approach to find the causal effect of having the disease. Weights were calculated by a propensity score method using a Random Forest model. The flexibility of this machine learning algorithm allows to have a better specification and bias reduction. Additionally, we reported incremental costs and cost ratios with confidence intervals using bootstrapping and analyzed costs by age groups and complications associated with diabetes. ResultsThe estimated prevalence of diabetes was 2834 per 100 000 cases, in 2018. The group with diabetes was comprised 634 015 people and the control group 1 524 808. The calculated annual direct medical cost was $860, for which the incremental cost was $493 and the cost ratio 2.34. The incremental annual cost for some type of complication ranges from $1239 to $2043, renal complication being the most expensive. Incremental cost by age groups ranges from $347 to $878, being higher in younger people. ConclusionsAlthough the cost of diabetes in Colombia ranges among the global averages and is similar to other Latin-American countries, a greater incremental cost was found in patients with renal, circulatory, and neurologic complications.

Coronavirus Disease 2019 Pandemic and Reduced Surgical Site Infection After Cardiac Surgery: A Potential Blessing in Disguise.

Background: The coronavirus disease 2019 (COVID-19) pandemic has brought about drastic hygienic measures, one upside of which might be the mitigated occurrence of surgical site infection (SSI). This study investigated the association of the pandemic with SSI occurrence after cardiac surgeries. Patients and Methods: From 2014 to 2022, patients undergoing cardiac surgery were included and categorized into pre-pandemic and during-pandemic groups. Surgical site infections were classified into harvest-site, superficial sternal, and complex sternal infection. Multiple logistic regression and inverse probability weighting assessed the association of the pandemic with SSI. Results: Among a total of 26,143 patients, 793 SSIs occurred. The during-pandemic patients were younger (61.87 ± 10.58 vs. 65.64 ± 11.82) with a higher male proportion (70.1% vs. 67.4%) and a higher prevalence of all studied comorbidities/risk factors (expect cigarette smoking). Total SSI rate decreased substantially from 3.3% before COVID-19 to 1.8% afterward (p < 0.001). Inverse probability weights analyses evinced an independent association of the pandemic with a reduced risk of total (adjusted odds ratio [OR]; 0.59; 95% confidence interval [CI], 0.45-0.78), harvest-site (adjusted OR, 0.36; 95% CI, 0.19-0.70), and superficial sternal infection (adjusted OR, 0.60; 95% CI, 0.43-0.81). No significant association was observed with complex sternal site infection (adjusted OR, 1.05; 95% CI, 0.55-2.01). Multivariable regression recapitulated these findings. Conclusions: The COVID-19 pandemic independently pertained to more than a 40% reduction in SSI occurrence, particularly affecting harvest-site and superficial sternal infections. However, there remains the possibility of the implications of other known and unknown confounders on the observed association. To some extent, the decrease in SSIs after the pandemic can be justified by reinforced hygienic precautions, emphasizing the necessity of extending the adherence to these measurements into the post-COVID-19 era to maintain the status quo.

Abstract PO4-23-04: Is breast-conserving surgery an optional local therapy for non-inflammatory skin involvement (T4b) breast cancer? A Propensity Score Matching and Inverse Probability Weighting Analysis of SEER Database Results

Abstract Introduction: Although breast-conserving surgery (BCS) usage has been widespread in breast cancer treatment, it is still controversial about its application in non-inflammatory skin involvement (T4b) breast cancer. We designed this study to compare the prognosis for BCS versus mastectomy in this population. Methods: This retrospective cohort study included patients from the SEER database diagnosed with tumor stage T4b breast cancer from 1998 to 2019. To create prognostic factors, balance between BCS+RT and Mastectomy+RT groups, we calculated propensity scores for each patient. The calculation was based on the advance assessment for factors affecting prognosis, with the use of univariable and multivariable Cox proportional hazards models. Based on it, two propensity score-based matchings were conducted, including propensity score matching (PSM) and inverse probability weighting (IPTW). After adjustment, we performed Kaplan-Meier curves and multivariable Cox proportional hazards models to estimate BCSS and OS. Results: Of 4,680 patients who met the criterion, 588 received BCS+RT, and 4092 received Mastectomy+RT. In the propensity score matching (PSM) cohort, BCS+RT was found to improve breast cancer cause-specific survival (HR, 0.67; 95% CI, 0.53 to 0.85; p=0.001) and overall survival (HR, 0.72; 95% CI, 0.59 to 0.88; p=0.001). Similar results in the analysis of the IPTW-matched cohort confirm this result (BCSS: HR, 0.672; OS: HR, 0.722). Subgroup analysis revealed that those less than 70 years old, grade I+II, 3cm or smaller tumor size, hormone receptor-positive, or received chemotherapy treatment were more likely to benefit from BCS+RT (all p&amp;lt; 0.05). Conclusions: Locally treatment with BCS usage presented a significantly better survival than with mastectomy for non-inflammatory skin involvement (T4b) breast cancer patients. This finding provided evidence of selection in the local treatment of these patients. Citation Format: Jingyi Lin, Shiping Luo, Jie Zhang, Chuangui Song. Is breast-conserving surgery an optional local therapy for non-inflammatory skin involvement (T4b) breast cancer? A Propensity Score Matching and Inverse Probability Weighting Analysis of SEER Database Results [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-23-04.

Investigating the causal association of generalized and abdominal obesity with microvascular complications in patients with type 2 diabetes: A community-based prospective study.

The paradoxical protective association between overweight/obesity and diabetic microvascular complications (DMC), a phenomenon well-known as the obesity paradox, has been considered a non-causal association based on methodological influences. We aimed to investigate the association of generalized and abdominal obesity, as measured by body mass index (BMI) and waist circumference (WC), respectively, with DMC in patients with type 2 diabetes (T2D), using a causal inference approach. We enrolled 1436 patients with clinically diagnosed T2D but not DMC at baseline in a community-based prospective cohort in China between 2017 and 2019 and followed them annually until 2022 with new-onset DMC recorded. Marginal structural Cox models with inverse probability weighting were constructed to determine the causal association. Subgroup analyses were performed to identify potential effect modifiers. We observed 360 incident DMC cases, including 109 cases of diabetic nephropathy (DN) and 277 cases of diabetic retinopathy (DR) during four follow-up visits. Multivariable-adjusted hazard ratios (95% confidence intervals) for overall DMC, DN and DR were 1.037 (1.005-1.071), 1.117 (1.062-1.175) and 1.018 (0.980-1.059) for 1 kg/m2 increase in BMI, and 1.005 (0.994-1.017), 1.034 (1.018-1.051) and 1.000 (0.987-1.014) for 1 cm increase in WC, respectively. Similar patterns were observed across the BMI and WC categories, while the positive association appeared to be more pronounced in women. Generalized but not abdominal obesity was associated with an increased risk for the overall DMC, whereas both obesities were causally related to DN, albeit not DR, in T2D. Routine weight management should not be neglected in diabetes care, particularly in women.