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Nevin Manimala Statistics

Does Timing Matter? Exploring the Effects of Measurement Error on Models

Bull Math Biol. 2026 May 19;88(6):88. doi: 10.1007/s11538-026-01649-9.

ABSTRACT

Measurement error is an unavoidable feature of experimental data collection. It is common in mathematical biology to consider measurement error in the dependent variable. However, less attention has been given to errors in the independent variable. This work is focussed on the effects of independent variable measurement error in the biological sciences and the available statistical methods to account for these errors when performing parameter inference. Through a series of synthetic data studies, the effects of various error models are investigated, with a particular focus given to error in the time a measurement is taken. Across many scenarios, parameter inference proves robust to these errors, even without directly accounting for them. However, we find some systems, such as oscillating systems, are particularly susceptible to these errors and parameter estimates become biased. To aid researchers in the biological sciences, we review some statistical methods to correct for measurement error. We assess the applicability of these methods in a biological context by considering data availability and necessary assumptions for the methods. We find measurement error can have non-trivial and counter-intuitive effects on parameter inference and suggest assessing the available data should be an integral step in the modelling workflow. This allows researchers to identify when the integration of statistical methods to correct for measurement error are warranted.

PMID:42154409 | DOI:10.1007/s11538-026-01649-9

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Nevin Manimala Statistics

Sleep status among adults

Sleep Breath. 2026 May 19;30(3):165. doi: 10.1007/s11325-026-03713-z.

ABSTRACT

BACKGROUND: Sleep disorders present a substantial challenge to public health. This study aims to analyze patterns in self-reported trouble sleeping, duration of sleep, and the utilization of prescription medications commonly used for insomnia (MCUFI) among the adult in the US.

METHODS: Data from five cycles of cross-sectional studies were gathered via the National Health and Nutrition Examination Survey (NHANES) spanning the years 2009 to 2010 through 2017 to 2018. Participants were asked to self-report on their trouble sleeping and sleep duration.

RESULTS: The prevalence of self-reported trouble sleeping rose noticeably from 24.93% (95% confidence interval [CI],22.73%-27.28%) in 2009-2010 to 30.03% (95%CI, 27.22%-33.00%) in 2017-2018 (P for trend = 0.001). In 2017-2018, 24.25% (95%CI, 22.04%-26.60%) reported < 7 h of sleep, which is a decreased of 11.94% since 2009-2010, while those reported ≥ 9 h increased from 7.14% (95%CI, 6.21%-8.20%) to 20.89% (95%CI, 19.90%-21.92%). However, those who slept for 7-9 h did not experience a significant change. Moreover, a U-shaped relationship was observed between sleep duration and trouble sleeping, indicating that the optimal amount of sleep for adults is 7.5 h. Furthermore, 3.72% (95%CI, 3.39%-4.09%) of adults used a MCUFI, with the most commonly used medications being zolpidem and trazodone. The overall MCUFI use did not change from 2009 to 2018 (P for trend = 0.9923).

CONCLUSION: In conclusion, the prevalence of self-reported trouble sleeping has risen in the US during the past decade, whereas the utilization of MCUFI has remained steady. Evidence from this study has shown that a sleep duration of 7.5 h is the optimal time for sleep with the lowest risk of encountering trouble sleeping.

PMID:42154404 | DOI:10.1007/s11325-026-03713-z

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Nevin Manimala Statistics

Integrated assessment of developmental toxicity of antibiotic pollutants: Machine learning prediction, zebrafish validation, and network toxicology

Mol Divers. 2026 May 19. doi: 10.1007/s11030-026-11589-0. Online ahead of print.

ABSTRACT

Developmental toxicity induced by environmental pollutants, particularly antibiotics, is often insidious and underestimated due to bioaccumulation and subsequent oral intake. This study developed a machine learning-based predictive strategy by constructing and comparing four models using Morgan fingerprints on a curated dataset of developmental toxicants. The optimal random forest model achieved an area under the receiver operating characteristic curve (AUC) of 0.87 (95% confidence interval: 0.83-0.91), an accuracy of 0.80, and a Matthews correlation coefficient of 0.59. Applying the ensemble model to 2,341 antibiotics identified miconazole as the highest-probability candidate (average probability 0.97). In zebrafish embryo toxicity assays, exposure to miconazole at low concentrations (0.3 and 3.0 µM) did not result in statistically significant mortality up to 72 h post-fertilization, whereas the high concentration (30 µM) caused significantly elevated mortality at 48 and 72 h (p < 0.05 compared to control). Network toxicology and molecular docking revealed that miconazole may interact with key targets AKT1 and BRAF, potentially perturbing the chemical carcinogenesis-reactive oxygen species signaling pathway. These integrated findings indicate that miconazole exhibits potential developmental toxicity, warranting further mechanistic and long-term exposure studies before drawing definitive regulatory conclusions.

PMID:42154399 | DOI:10.1007/s11030-026-11589-0

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Nevin Manimala Statistics

Evaluating hospital performance

Eur J Health Econ. 2026 May 19. doi: 10.1007/s10198-026-01936-1. Online ahead of print.

ABSTRACT

Patient selection remains a major challenge in evaluating hospital performance. We exploit the quasi-random assignment of patients to hospitals, based on a rotation schedule between hospitals in the Upper Austrian capital of Linz. In an instrumental variable (IV) framework, we use high-quality administrative data and estimate hospital performance with respect to in-hospital mortality, 30-day mortality, and 30-day readmission. We contrast these results with those of traditional risk adjustment models based on patient observables. We find that the assessment of hospital performance is sensitive to the inclusion of patient observables and that increasing the number of socio-economic covariates to better control for patient risk profiles does not always help bring risk-adjusted estimates closer to IV estimates. The divergence between methods is most pronounced for readmissions, where risk-adjustment models imply large and statistically significant differences between hospitals, whereas IV estimates are substantially smaller and not statistically significant. Our results suggest that common risk adjustment does not adequately control for patient differences between hospitals and that hospital quality indicators based on common administrative data should be interpreted with caution. The trend toward personalized medicine may support the process of collecting more clinical information at the individual level, thus allowing for better quality comparisons between hospitals.

PMID:42154359 | DOI:10.1007/s10198-026-01936-1

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Nevin Manimala Statistics

Impact of the SUture BIte TEchnique on clinical outcomes after midline laparotomy closure: SUBITE-a systematic review and meta-analysis

Hernia. 2026 May 19;30(1):221. doi: 10.1007/s10029-026-03700-z.

ABSTRACT

BACKGROUND: The objective of this Systematic Review and Meta-Analysis (SR/MA) was to identify the best suture technique (short or large bites) for abdominal wall closure with respect to relevant outcome parameters such as incisional hernia (IH), surgical site infection (SSI) and linea alba (aponeurotic layer of the abdominal wall) dehiscence (LAD).

METHODS: Registration was done in PROSPERO, a systematic literature search was performed in three data bases (PubMed, Embase and Cochrane). Randomised controlled (RCT) as well as non-randomised controlled trials (n-RCT) comparing the short (SB) versus large bite (LB) technique for abdominal wall closure after midline laparotomy were eligible for inclusion. Quality assessment was performed for RCTs (ROB) & n-RCTs (ROBINS-1, MINORS). The incidence of IH, SSI, LAD as well as the length of hospital stay (LOS) and time to close the linea alba (aponeurotic layer of the abdominal wall) were analysed as outcome parameters. Odds ratio with 95% confidence intervals were chosen to determine statistical significance. Heterogeneity was explored using the I2-statistics and funnel plots evaluated a possible publication bias.

RESULTS: This SR/MA comprised in total 5886 patients (large bite group 3339 vs. 2547 short bite group) enrolled in 7 RCTs and 5 n-RCTs. The SB-technique was associated with a significant lower IH, SSI, FD rate and a shorter LOS compared to the LB-technique (IH: Odds Ratio OR = 0.47 (95% CI 0.38-0.58; p < 0.00001; I2 = 11%)); SSI: OR = 0.53 (95% CI 0.42-0.67; p < 0.00001; I2 = 0%); FD: OR = 0.60 (95% CI 0.38-0.93; p = 0.02; I2 = 0%); LOS: Mean difference in days MD = -1.04 (95% CI -1.70, -0.37; p = 0.002; I2 = 13%), respectively). Furthermore, pooled effect estimates derived from RCTs were comparable to n-RCTs. No statistical relevant publication bias was detected, and the confidence of resulting evidence was high according to the validated GRADE tool.

CONCLUSION: This systematic review and meta-analysis demonstrate consistent reductions in incisional hernia and surgical site infection with the small bites technique for midline laparotomy closure. The direction of effect is stable across randomized and comparative studies and supported by available long-term data. The clinical relevance and consistency of these findings support preferential use of the small bites technique in routine practice. The present evidence provides a robust basis for consideration in future updates of EHS abdominal wall closure guidelines.

REGISTRATION: PROSPERO, registration number: CRD420251033244, registration date: 16th April 2025.

PMID:42154339 | DOI:10.1007/s10029-026-03700-z

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Nevin Manimala Statistics

Morphologic variations of the sigmoid sinus on computed tomography: a classification-based study

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

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Nevin Manimala Statistics

Optimal Harvesting in Stream Networks: Maximizing Biomass and Yield

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

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Nevin Manimala Statistics

Machine learning and dose response effect models: an integrated approach to analyze the association between environmental variables and Cuneo Emergency Department admissions for Acute Otitis Media (2007-2015)

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

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Nevin Manimala Statistics

Marital status and post-radical prostatectomy outcomes: results from the SEARCH database

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

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Nevin Manimala Statistics

Prospective observation study of incision and drainage vs drainage and initial fistula management for perianal abscesses

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