Tag: statistics

Surg Radiol Anat. 2026 May 19;48(1):127. doi: 10.1007/s00276-026-03894-y.

ABSTRACT

PURPOSE: The sigmoid sinus is a vital dural venous structure whose anatomical variability has direct implications for lateral skull base and otologic surgeries. Understanding the sinus’s positional variations is considered important for minimizing surgical risks. This study aimed to evaluate the morphological classification of the sigmoid sinus using a surgical reference-based system and to assess its relationship with demographic variables.

METHODS: A retrospective analysis was conducted on high-resolution temporal bone CT scans of 241 patients (114 females [47.30%], 127 males [52.70%]) with an age range of 18-92 years (mean age: 47.95 ± 17.84). The morphology of the sigmoid sinus was classified into four types based on the system defined by Dong-Il Sun et al., using three anatomical reference lines. The width and depth of the sigmoid sinus were measured bilaterally and analyzed in relation to age and gender. Statistical analysis included paired tests for bilateral measurements, chi-square tests and ordinal logistic regression for associations with age and sex, and reliability assessment using Cohen’s kappa and intraclass correlation coefficients.

RESULTS: A total of 241 patients were included. Mean sigmoid sinus depth and width were 6.57 ± 1.73 mm and 14.55 ± 4.06 mm on the right, and 6.33 ± 1.52 mm and 15.18 ± 4.93 mm on the left, respectively. Left-sided width was significantly greater than the right (p < 0.05), whereas depth did not differ. Type 3 and Type 4 configurations predominated bilaterally; Type 1 was not observed. Age was significantly associated with left-sided sigmoid sinus type (p = 0.0048), with more medial configurations in older individuals. Ordinal regression showed decreasing odds of higher-type anatomy with increasing age (OR = 0.84 per decade). Gender was associated with left-sided type distribution but not independently predictive after adjustment. Inter- and intraobserver reliability was excellent.

CONCLUSION: The positional morphology of the sigmoid sinus varies significantly with age and gender. The absence of Type 1 and predominance of high-risk configurations in younger individuals suggests the potential relevance of individualized preoperative assessment. This classification system may provide additional anatomical insight for radiologic evaluation; however, its direct impact on surgical decision-making requires further validation.

PMID:42154332 | DOI:10.1007/s00276-026-03894-y

Bull Math Biol. 2026 May 19;88(6):91. doi: 10.1007/s11538-026-01658-8.

ABSTRACT

In this study, we develop a metapopulation model framework to identify optimal harvesting strategies for a population in a stream network. We consider two distinct optimization objectives: maximization of total biomass and maximization of total yield, under the constraint of a fixed total harvesting effort. We examine in detail the special case of a two-patch network and fully characterize the optimal strategies for each objective. We show that when the population growth rate exceeds a critical threshold, a single harvesting strategy can simultaneously maximize both objectives. For general n-patch networks with homogeneous growth rates across patches, we focus on the regime of large growth rates and demonstrate that the optimal harvesting strategy selects patches according to their intraspecific competition rates and an effective net flow metric determined by network connectivity parameters.

PMID:42154324 | DOI:10.1007/s11538-026-01658-8

Int J Biometeorol. 2026 May 19;70(6):168. doi: 10.1007/s00484-026-03226-0.

ABSTRACT

Acute otitis media (AOM) is a leading cause of pediatric Emergency Department visits, particularly among children under five years of age. Although its seasonal pattern is well established, the role of air pollution and meteorological factors remains unclear. This study aims to investigate their impact on daily AOM visits by integrating machine learning and epidemiological approaches. We conducted a retrospective analysis of pediatric AOM diagnoses (2007-2015) at S. Croce and Carle Hospital (Cuneo, Italy). Predictors included PM10, NO₂, O₃, and eleven meteorological variables. Ensemble machine learning models (Random Forest, XGBoost, and AdaBoost) were trained and validated using 10-fold cross-validation. Model interpretability was assessed through SHAP values. Distributed Lag Nonlinear Models (DLNM) were applied to estimate delayed exposure-response relationships over lag periods of 0-1, 0-3, 0-5, and 0-10 days, with results expressed as Relative Risks (RRs) and 95% Confidence Intervals (CIs). AdaBoost showed the best performance (R² = 0.974; MAE = 0.019 cases/day; cross-validated R² = 0.987). SHAP analysis identified mean temperature as the most influential predictor (44%), while PM10, NO₂, and O₃ each contributed approximately 10%. DLNM analysis confirmed a strong and consistent effect of temperature across all lag periods (RR > 1.20, CI > 1). Moderate associations were observed for NO₂ and PM10 (RR: 1.02-1.04). O₃ exhibited smaller but significant effects at shorter lags (RR = 1.01 at 0-1 days; RR = 1.02 at 0-3 days; CI > 1). Environmental factors, particularly temperature, play a significant role in pediatric AOM incidence. The integration of machine learning and DLNM enhances predictive accuracy and improves the understanding of exposure timing. These findings support the development of early warning systems and targeted preventive strategies under adverse environmental conditions. Further validation in larger urban settings is needed.

PMID:42154319 | DOI:10.1007/s00484-026-03226-0

Support Care Cancer. 2026 May 19;34(6):559. doi: 10.1007/s00520-026-10783-y.

ABSTRACT

PURPOSE: Social support, specifically marital status, has been shown as a significant prognostic factor for survival of multiple malignancies, including prostate cancer. However, this has not been investigated in an equal access Veterans Affairs (VA) cohort where other support systems exist that may minimize the potential benefit of social support from a partner.

METHODS: We retrospectively reviewed data from 9,931 patients undergoing primary radical prostatectomy (RP) in the VA from 1988-2020 across 9 VA centers. Univariable and multivariable Cox proportional hazards models were used to test the association between marital status and biochemical recurrence (BCR), metastasis, castration-resistant PC (CRPC) and prostate cancer specific mortality (PCSM).

RESULTS: 8,285 patients met the inclusion criteria: 54% were married, 30% were divorced/separated, 9% were single/never married, and 6% were widowed at the time of RP. Single/never married men were younger (median 61 vs 62-65 years), had surgery more recently (median 2009 vs 2003-2008), had higher PSA (median 6.9 ng/mL vs 6.4-6.8 ng/mL), and had lower BMI (median 27 vs 28) compared to other groups (all p < 0.05). The median time to BCR was significantly shorter for divorced/separated men (188.2 months) and single/never married men (154.8 months) compared to married men (243.0 months). Consistent with this finding, compared to married men, divorced/separated men had higher risk of BCR (HR = 1.12; 95% CI 1.03-1.21), as did single/never married men (HR = 1.13; 95% CI 1.00-1.28). However, these associations were insignificant in multivariable analyses (all p > 0.05).

CONCLUSION: Among men with localized prostate cancer undergoing RP within the VA, we found no association between marital status-defined as a demographic indicator of self-reported relationship category-and oncologic outcomes. Whether marital satisfaction or perceived partner support, which were not assessed in this study, influence post-RP outcomes remains to be investigated.

PMID:42154317 | DOI:10.1007/s00520-026-10783-y

Langenbecks Arch Surg. 2026 May 19. doi: 10.1007/s00423-026-04078-3. Online ahead of print.

ABSTRACT

BACKGROUND: Perianal abscess is a common anorectal emergency, and simple incision and drainage (I&D) remains the standard initial treatment. However, failure to address an underlying fistulous tract at the primary surgery may result in high rates of abscess recurrence and subsequent fistula formation. The role of drainage with concurrent initial fistula management remains debated due to concerns regarding anal continence.

AIM: To compare outcomes of simple incision and drainage versus drainage with initial fistula management in patients with acute perianal abscess, with special reference to abscess recurrence.

METHODS: This Prospective observation studies was conducted in the Department of General Surgery at SRM Medical College Hospital and Research Centre from march 2025 to December 2025. A total of 142 patients with acute perianal abscess were randomized into two groups: Group A underwent simple I&D (n = 71) and Group B underwent I&D with primary fistula management (n = 71). Patients were followed for 10 months. Primary outcomes included abscess recurrence and fistula formation. Secondary outcomes included anal incontinence assessed using the Fecal Incontinence Severity Index (FISI), postoperative pain, wound healing time, and hospital stay. Statistical analysis was performed using SPSS v25.0 with p < 0.05 considered significant.

RESULTS: Abscess recurrence was significantly higher in the simple drainage group (23.9%) compared to the drainage with fistula management group (4.2%) (p = 0.001). Fistula formation occurred exclusively in the simple drainage group (25.4%) (p < 0.001). Mean FISI scores were higher following simple drainage (5.10 ± 3.15) than drainage with fistula management (3.30 ± 2.13) (p < 0.001). Hospital stay was significantly shorter in the combined procedure group (p < 0.001), while postoperative pain scores were comparable.

CONCLUSION: Drainage with initial fistula management significantly reduces abscess recurrence and fistula formation without increasing postoperative pain, and is associated with better continence outcomes and shorter hospital stay compared to simple drainage alone.

PMID:42154297 | DOI:10.1007/s00423-026-04078-3

Trop Med Int Health. 2026 May 19. doi: 10.1111/tmi.70168. Online ahead of print.

ABSTRACT

OBJECTIVE: To analyse the epidemiological characteristics, spatial distribution and predictors of TB-related mortality in Risaralda from 2020 to 2024.

METHODS: A retrospective observational study was conducted using secondary data from the National Public Health Surveillance System (SIVIGILA). Descriptive statistics, spatial analysis (choropleth maps) and binary logistic regression were used to identify sociodemographic and clinical factors associated with TB case fatality. Model performance was evaluated using ROC curves, sensitivity, specificity and 5-fold cross-validation.

RESULTS: A total of 2081 confirmed TB cases were analysed, with a case fatality rate of 13.2%. Mortality was higher among individuals ≥ 65 years (OR: 3.87), hospitalized patients (OR: 7.33), HIV-positive individuals (OR: 3.49), those with undernutrition (OR: 1.89), males (OR: 1.45) and Indigenous persons (OR: 1.67). The logistic model showed good discrimination (AUC: 0.82), with sensitivity of 79.2% and specificity of 73.8%. Cross-validation confirmed model stability (AUC: 0.81). Spatial analysis revealed high mortality in rural municipalities with low case burden, suggesting health inequities.

CONCLUSION: TB mortality in Risaralda is influenced by age, comorbidities and social determinants, with pronounced territorial disparities. These findings support the integration of spatial and predictive tools in TB surveillance to strengthen targeted interventions and reduce mortality in high-risk populations.

PMID:42153348 | DOI:10.1111/tmi.70168

Database (Oxford). 2026 Jan 15;2026:baag026. doi: 10.1093/database/baag026.

ABSTRACT

Cancer metastasis involves complex molecular mechanisms that cannot be fully explained by individual gene expression profiles. Previous studies have shown that correlations between RNA and miRNA expression can capture metastatic behaviour more effectively than expression of individual genes. However, no publicly available databases provide systematic analysis of RNA-miRNA correlations specific to cancer metastasis. We developed an efficient computational method to identify differential correlations between miRNAs and RNAs that are specific to individual tumour samples. Using data from The Cancer Genome Atlas (TCGA), we computed differential correlations for tumour samples across 9 cancer types and 21 metastatic sites, encompassing ~200 million RNA-miRNA pairs. Statistical analysis identified RNA-miRNA pairs with site-specific correlations using Mann-Whitney U-tests. MetaCancerDB contains RNA-miRNA correlation networks for 9 primary cancer types and 21 metastatic sites. Site-specific correlations showed distinct patterns, with lung metastasis displaying the most conserved correlations across cancer types. Survival analysis revealed that specific RNA-miRNA pairs are prognostic for patient outcomes in a metastatic site-dependent manner. MetaCancerDB provides a comprehensive resource for exploring RNA-miRNA correlations in cancer metastasis. The database enables researchers to identify molecular signatures specific to metastatic sites and can serve as a foundation for developing predictive biomarkers. MetaCancerDB is freely available for academic purposes.

PMID:42153344 | DOI:10.1093/database/baag026

Biostatistics. 2026 Jan 20;27(1):kxag009. doi: 10.1093/biostatistics/kxag009.

ABSTRACT

A live clinical question is: which patients benefit from intensive care unit (ICU) transfer? Motivated by this question we address the problem of estimating conditional average treatment effects (CATE) in the presence of unmeasured confounding, by leveraging instrumental variables (IVs). CATE-learners (eg R-learner) developed for settings without unmeasured confounding can readily incorporate IVs by substituting the observed exposure with first-stage predictions from a regression of treatment on IVs and covariates. Such predictions may be obtained via flexible data-adaptive methods (eg statistical or machine learning procedures) to alleviate concerns about model misspecification. However, the large regularization bias typical of data-adaptive predictions may propagate into the CATE estimates, resulting in poor accuracy. Neyman-orthogonal learners have therefore been developed, which prevent this by “insulating” the resulting CATE estimates against bias and estimation errors in these predictions. However, synthetic data simulations reveal that previously proposed Neyman-orthogonal learners for IV regression perform poorly. We remedy this problem using infinite-dimensional targeted learning, which strategically tailors first-stage predictions to perform well in their ultimate task: delivering accurate, precise CATE estimates. The resulting targeted Neyman-orthogonal learner is easy to construct based on arbitrary, off-the-shelf learners. It can handle continuous or discrete exposures, and arbitrary types and numbers of IVs and covariates. Simulation studies and a re-analysis of the benefits of ICU transfer show substantial enhancements in performance, underscoring the importance of the proposed IV-learner.

PMID:42153341 | DOI:10.1093/biostatistics/kxag009

J Rural Health. 2026 Mar;42(2):e70167. doi: 10.1111/jrh.70167.

ABSTRACT

PURPOSE: This study examined whether the Supportive Services for Veteran Families (SSVF) program has a differential impact on healthcare utilization and costs among rural and urban Veterans experiencing housing instability. Understanding geographic variation in program effects is important for guiding implementation and resource allocation within the Veterans Affairs (VA) healthcare system.

METHODS: We conducted a retrospective cohort study using national VA administrative data from October 1, 2018 to September 30, 2023. Veterans were classified as SSVF participants or eligible non-SSVF Veterans based on indicators of housing instability. A target trial emulation framework with inverse probability weighting was used to adjust for baseline differences. Rurality was defined using Rural-Urban Commuting Area codes applied to Veterans’ residential addresses recorded in VA administrative data. Weighted longitudinal models estimated quarterly changes in healthcare utilization and costs and tested whether effects varied by rurality.

FINDINGS: SSVF enrollment was associated with reductions in inpatient utilization and costs and modest increases in outpatient visits, resulting in overall decreases in total VA healthcare costs. Emergency department use showed small reductions among urban Veterans and little measurable change among rural Veterans. Overall patterns of healthcare utilization and spending were similar across rural and urban Veterans, and statistical tests did not indicate significant rural-urban differences in SSVF effects.

CONCLUSIONS: SSVF participation was associated with shifts away from inpatient care and toward greater outpatient engagement among Veterans experiencing housing instability. These patterns were observed among both rural and urban Veterans, suggesting that the healthcare benefits of housing stabilization programs are similar across geographic settings.

PMID:42153335 | DOI:10.1111/jrh.70167

J Anim Sci. 2026 May 18:skag159. doi: 10.1093/jas/skag159. Online ahead of print.

ABSTRACT

Selenium (Se) is known to improve gut health in animals, yet research on the effects of different dietary Se compounds on the intestinal health of broilers remains limited. Therefore, this study evaluated the effects of sodium selenite (SS), selenium-enriched yeast (SY), selenomethionine (SM), and nano-selenium (NS) on gut microbiota and their metabolites, intestinal antioxidant capacity, immune response, and gut morphology in broilers, and investigated the potential molecular mechanisms by which Se influences intestinal function in broilers. A total of 360 1-day-old male yellow-feathered broilers with an average body weight of 37.00 ± 0.17 g were randomly assigned to five treatments, each comprising six replicates with 12 chicks per replicate. Broilers received either a basal diet or a basal diet supplemented with SS, SM, SY, and NS at 0.5 mg Se/kg for 56 days. Data were analyzed using one-way ANOVA with Tukey’s post-hoc test for multi-group comparisons, and statistical significance was set at P < 0.05. Supplementation with SY increased ileal concentrations of secretory immunoglobulin A by 74.87% and interleukin-10 (IL-10) by 54.90%, enhanced ileal activities of total superoxide dismutase (T-SOD) by 123.55% and catalase by 197.20%, and elevated cecal acetate by 35.67% and total short-chain fatty acids (SCFAs) by 28.78%, as well as ileal ursodeoxycholic acid concentration by 154.05% (P < 0.05). Dietary SS elevated ileal IL-10 concentration by 44.72% and glutathione peroxidase activity by 93.74% while reducing tumor necrosis factor-alpha level by 26.46% (P < 0.05). Supplemental NS increased cecal concentrations of acetate by 45.56%, propionate by 85.94%, and total SCFAs by 39.68% (P < 0.05). Compared with the SS, SY supplementation improved jejunal total antioxidant capacity by 81.08% and ileal T-SOD activity by 84.22% (P < 0.05). Additionally, dietary Se supplementation increased the abundances of potentially beneficial bacteria, including Lactobacillus, Parabacteroides, Akkermansia, and UCG_005 (P < 0.05). Genes such as CCR9, CD28, MUC2, HTR6, KCNK5, and SLC9A3 were up-regulated, while GIP, SSTR2, SST1, and CRHR1 were down-regulated by SS or SY supplementation, indicating involvement in intestinal function. In summary, SS and SY improved intestinal antioxidant and immune functions in broilers, whereas SY and NS enhanced cecal SCFAs production. Moreover, Se supplementation modulated the cecal microbial community in broilers.

PMID:42153328 | DOI:10.1093/jas/skag159