Category: Statistics

Comput Methods Programs Biomed. 2026 May 22;285:109458. doi: 10.1016/j.cmpb.2026.109458. Online ahead of print.

ABSTRACT

BACKGROUND: Ventricular late potentials (VLPs) are markers of arrhythmogenic substrate, but conventional assessment using signal-averaged ECG (SAECG) requires prolonged acquisition and operator-dependent artifact handling, limiting scalability and ambulatory use. Single-beat detection of VLP-like activity from standard surface ECG remains insufficiently validated.

OBJECTIVE: To evaluate the technical feasibility of interpretable single-beat detection of VLP-like perturbations from standard ECG leads without signal averaging.

METHODS: Using the MIMIC-IV-ECG database, we analyzed 120,000 beats from leads II, V2, and V6. Because large public datasets with beat-level clinically adjudicated VLP labels are not currently available, physiologically constrained synthetic VLP-like signals were injected into a subset of beats to create a controlled feasibility benchmark. For each beat, more than 200 features were extracted, including time-domain statistics, frequency-domain measures, wavelet coefficients, autocorrelation features, and localized windowed summaries. Ten classifiers were optimized using nested patient-wise cross-validation and evaluated in five settings: single-lead detection, cross-lead generalization, mixed-lead training, reduced training size, and class-imbalance robustness.

RESULTS: Gradient-boosted ensembles, particularly XGBoost and CatBoost, achieved strong discrimination on held-out single-beat data (AUC > 0.99; F1 > 0.93), while remaining stable with 10% of the training data and 5% positive-class prevalence. Performance was also robust in lead-transfer experiments. SHAP analysis identified localized entropy, dispersion, and related high-frequency descriptors in late post-R windows as the dominant predictors.

CONCLUSION: These findings support the methodological feasibility of interpretable single-beat detection of VLP-like signatures from routine surface ECG under controlled synthetic conditions. Validation on clinically adjudicated cohorts and external datasets is required before clinical translation.

PMID:42229036 | DOI:10.1016/j.cmpb.2026.109458

J Anxiety Disord. 2026 May 28;122:103188. doi: 10.1016/j.janxdis.2026.103188. Online ahead of print.

ABSTRACT

The 12-item Intolerance of Uncertainty Scale (IUS-12) is a widely used measure in anxiety disorders research and clinical practice, although recent research efforts have recommended the development of a briefer measure to reduce response burdens. The current study was designed to develop a short form of the IUS-12. We administered the IUS-12 to two samples (cross-sectional, n = 3952; longitudinal, n = 190) of Canadian Public Safety Personnel through an online self-report survey. Exploratory (EFA) and confirmatory (CFA) factor analyses assessed the factor structure of the IUS-12 and facilitated item reduction and optimization. Convergent and concurrent validity, as well as pre-post rank-order consistency were also assessed. The IUS-12 was reduced to a two-factor, six-item short form (i.e., IUS-6) that retains the factor structure of the IUS-12 with statistically comparable validity and consistency, which appears to retain the intended latent content for each subscale. Very strong statistically significant positive correlations were observed between IUS-6 and IUS-12 subscales (rs = .90-.94) and total scores (r = .95) for all samples, suggesting excellent construct validity. Moderate to strong statistically significant associations were also observed among the IUS-6 and IUS-12 total and subscales and measures of generalized anxiety, social anxiety, and anxiety sensitivity, suggesting good convergent validity (rs = .23-.64), with only small differences in correlation strengths (i.e., r < .14). The IUS-6 may be used as an ultra-short version of the IUS-12 for assessing self-reported intolerance of uncertainty in both cross-sectional and longitudinal research designs, potentiating reduced response burdens, which may be important in various research and clinical settings.

PMID:42229033 | DOI:10.1016/j.janxdis.2026.103188

Cogn Neurosci. 2026 Jun 2:1-2. doi: 10.1080/17588928.2026.2682170. Online ahead of print.

ABSTRACT

Slotnick (2026) provides a large number of simulations to demonstrate that statistical power in fMRI can be improved by including the sample size N when calculating an appropriate cluster extent threshold for thresholding statistical maps. I argue that the problems acknowledged by Slotnick can instead be solved using threshold free cluster enhancement (TFCE) and a permutation test, which together apply a large number of cluster forming thresholds and implicitly model the sample size as well as the spatial autocorrelation. Furthermore, I briefly mention some other approaches for increasing statistical power in fMRI.

PMID:42228992 | DOI:10.1080/17588928.2026.2682170

Neurodiagn J. 2026 Jun 2:1-13. doi: 10.1080/21646821.2026.2671520. Online ahead of print.

ABSTRACT

INTRODUCTION: Linked Quadripolar Stimulation (LQP) is a recent adaptation of transcranial electric motor evoked potential stimulation, with proposed advantages over traditional Bipolar (BP) stimulation. This study aims to comprehensively compare BP and LQP stimulation to validate the efficacy of LQP.

METHODS: BP and LQP stimulation were performed on 30 patients undergoing anterior cervical discectomy and fusion. A comprehensive assessment involved conducting four trials for each technique on each patient. An Accelerometer placed over the right masseter region recorded movement. A Mann-Whitney U test and Pearson Correlation Coefficient were used to quantitatively compare patient movement, compound muscle action potential (CMAP) response amplitude, and area under the curve (AUC) values.

RESULTS: TCMEP recordings were successfully obtained from the entire sample. No statistical significance was found between patient movement, amplitude, or area under the curve (AUC) between BP and LQP stimulation. A weak correlation was found between patient movement and stimulation intensity for both techniques. A strong correlation was found between amplitude and AUC values.

CONCLUSION: Patient movement and stimulation parameters showed similar outcomes between BP and LQP. LQP did not demonstrate reduced movement compared to BP stimulation. This study contributes valuable insights into the effectiveness of BP and LQP stimulation in anterior cervical discectomy and fusion surgery.

PMID:42228986 | DOI:10.1080/21646821.2026.2671520

Neurodiagn J. 2026 Jun 2:1-14. doi: 10.1080/21646821.2026.2659990. Online ahead of print.

ABSTRACT

The National Association of Epilepsy Centers mandates that epilepsy monitoring unit (EMU) patient observers must always be present to minimize risk of patient injury during admissions. To comply with this requirement, our staffing model and workflow were adjusted accordingly. Upon activation of the event button, rather than attending to EMU patients in person, the patient observer responded verbally through the room’s speaker system and subsequently contacted nursing staff via a Vocera™ device. This study evaluates the efficiency of this model by measuring the time between event button (PB) activation, observer response, and subsequent evaluation by either nursing staff or physicians. We retrospectively reviewed video EEG files for all available PBs on EMU patients admitted between January 1 and December 31, 2023, and calculated the intervals between PB activation, patient observer’s response, and in-person attendance by the health care provider. Patient demographics and event details were examined for statistical differences. Of 129 admissions (402 PBs), the median observer response time was 15 seconds, which increased with age (14 s, 16 s, and 20 s for <45, 45-64, and ≥65 yo, respectively; p = .027). The average time for a nurse or a physician to physically attend to the patient was 94 s (range, 4 to 1808 s). The average observer’s response to psychogenic non-epileptic seizures (PNES) was faster (10 s) than responses to epileptic seizures (14 s), accidents (15 s), and other events (17 s) (p < .001). There was no difference in response time between sexes (p = .870) or races (p = .197). Although patient observer response time was short, only 15% of PBs were seizure-related, while > 50% were accidental. These findings highlight the need to critically evaluate EMU staffing models to maintain compliance with the safety requirements, improve the accuracy of seizure detection, and to meet overall goals of EMU evaluation.

PMID:42228984 | DOI:10.1080/21646821.2026.2659990

Surg Laparosc Endosc Percutan Tech. 2026 Jun 1;36(3):e1448. doi: 10.1097/SLE.0000000000001448.

ABSTRACT

BACKGROUND AND AIMS: Esophageal foreign body (FB) impaction demands timely gastroscopic extraction, yet the need for preoperative radiographic imaging (PORI) varies by patient. To date, no validated risk-stratification tools exist to guide clinicians in determining the necessity of PORI before gastroscopic FB extraction. This study aims to fill this gap by developing a novel esophageal FB symptom score (EFBSS) to stratify patients at risk of severe complications, thereby providing a personalized approach to PORI decision-making.

METHODS: Patients with suspected FBs were retrospectively categorized into PORI or non-PORI groups. Gastroscopic success rate, complications, and survival prognosis were compared and analyzed between the 2 groups. Logistic regression was used to identify risk factors for FB-related perforation or surgical complications. A risk stratification system (low-risk: 0 to 3; moderate-risk: 4 to 6; high-risk: 7 to 9 points) was then built based on the likelihood of such complications to guide PORI decision-making.

RESULTS: There was no statistically significant difference between the PORI group (n=749) and the non-PORI group (n=1751) in the main outcome indicators, such as disease characteristics, FB types, incidence of complications, gastroscopic success rate, and survival prognosis (P>0.05). However, the PORI group had a longer duration of FB impaction and higher outpatient costs than the non-PORI group (P<0.05). The EFBSS includes swallowing FBs with pain, intentional ingestion of FBs, and cervical/chest/abdominal pain, with good discriminative power. The total score had an area under the receiver operating characteristic curve (AUC) of 0.822 (95% CI: 0.736-0.908), while the AUCs for the 3 components were 0.716, 0.699, and 0.894, respectively. The EFBSS system stratified the risk of FB-related perforation or surgical complications into 3 tiers: low (0.41%), moderate (2.95%), and high (39.29%). A significantly increasing risk trend was observed across tiers (P<0.001).

CONCLUSIONS: We developed a risk scoring system incorporating swallowing FBs with pain, intentional ingestion of FBs, and cervical/chest/abdominal pain. This system preoperatively stratifies patients by the risk of FB-related perforation or surgical complications to facilitate PORI decision-making and maximize benefits.

PMID:42228962 | DOI:10.1097/SLE.0000000000001448

Integr Comp Biol. 2026 Jun 2:icag061. doi: 10.1093/icb/icag061. Online ahead of print.

ABSTRACT

Geometric morphometrics is a common tool that quantifies shape variation and has been used to explore morphological changes over ontogeny and investigate evolutionary relationships. Lionfishes are suction feeders that have cycloid scales. Cycloid scales in bony fishes are smooth, overlapping structures that have been hypothesized to serve multiple functions such as protection and streamlining the fish for efficient locomotion. Lionfish undulate their soft dorsal, anal, and caudal fins to move slowly through the water column, near the substrate. In this study we examined invasive lionfish, Pterois volitans, collected from public fishing derbies on the eastern coast of Florida. We used 2D geometric morphometrics to investigate lionfish scale variation along the length of the body from three regions (anterior, middle, caudal), and between sexes. We placed eight landmarks using anatomical loci on sixty scales from twenty specimens similar in size (TL = 170mm- 230mm). We hypothesized to observe significant scale shape variation among body regions and we expected to see shape variation between sexes, as males exhibit more aggressive behavior during mating. Lionfish showed significant shape differences among all regions (anterior, middle, and caudal), with scales being more elongated near the caudal fin. We also observed statistically significant shape differences between male and female scales. Specifically, females have wider scales in the middle body region and males have wider scales near the caudal fin. Overall, this study reveals more information about the morphology and sexual dimorphic traits of lionfish using unconventional specimen collection methods (public lionfish derbies). When conducting research on invasive species we emphasize the importance of utilizing public events sponsored by state and local organizations, which are already engaging the public to significantly reduce population sizes.

PMID:42228949 | DOI:10.1093/icb/icag061

Anesth Analg. 2026 Jun 2. doi: 10.1213/ANE.0000000000008107. Online ahead of print.

ABSTRACT

BACKGROUND: Oxytocin is the most widely used uterotonic for postpartum hemorrhage prevention, yet high-quality data comparing bolus versus infusion administration are limited. Given the very high uterine blood flow at term, rapid achievement of uterine tone is critical to minimize blood loss. We hypothesized that bolus administration leads to a greater likelihood of attaining adequate uterine tone at 2 minutes.

METHODS: In this randomized, double-blinded clinical trial, 121 patients undergoing elective cesarean delivery under spinal anesthesia were randomized 1:1 to receive oxytocin by bolus or infusion after cord clamping. Masked study drugs were prepared by the investigational pharmacy to maintain blinding of the anesthesiologist, obstetrician, and study personnel. The primary end point was adequate uterine tone at 2 minutes. Secondary end points included patient satisfaction, time to adequate uterine tone, quantitative blood loss, postpartum hemorrhage (blood loss greater than 1000 mL), and safety measures (heart rate, blood pressure, phenylephrine dose, chest pain, nausea/vomiting, additional uterotonic use, and intensive care unit admission).

RESULTS: Of 121 patients enrolled, 115 were analyzable (6 screen failures received no study drug); 114/115 received oxytocin per protocol. Baseline characteristics were similar between groups. Adequate uterine tone at 2 minutes (primary end point) was similar in bolus (50/60, 83.3%) vs infusion (43/55, 78.2%), P = .483. Patient satisfaction scores were also not significantly different (P = .495) between the two arms, with both the bolus and infusion arms having medians and interquartile range (IQRs) of (10 [IQR 10-10]). Median blood loss was slightly lower with bolus (558 mL [IQR 429-733]) vs infusion (687 mL [IQR 480-826], P = .0438; Hodges-Lehmann estimate of 82 mL [95% confidence interval {CI}, 2-168 mL]). Phenylephrine dosage and rates of postpartum hemorrhage, nausea, and additional uterotonic use were similar between groups (all P > .28). Rates of postpartum hemorrhage, hypotension, phenylephrine use, nausea, and additional uterotonic use were similar.

CONCLUSIONS: There was no statistically significant difference in the frequency of achieving adequate uterine tone at 2 minutes between oxytocin given by infusion or bolus. Although the bolus group demonstrated statistically lower blood loss, the magnitude of this difference was small (upper confidence limit of 168 mL) and is unlikely to be clinically significant. Both methods showed comparable safety profiles.

PMID:42228946 | DOI:10.1213/ANE.0000000000008107

Anesth Analg. 2026 Jun 2. doi: 10.1213/ANE.0000000000007978. Online ahead of print.

ABSTRACT

BACKGROUND: Anesthetic adjuvants used in multimodal analgesia-including intravenous lidocaine, dexmedetomidine, or intrathecal morphine (ITM)-may differentially affect immune responses and metastasis-related pathways in colorectal cancer surgery. Their comparative effects on these pathways remain poorly understood.

METHODS: In this prospective, randomized, patient- and assessor-blinded trial, adults undergoing elective laparoscopic or robotic colorectal cancer resection were allocated to receive intravenous lidocaine, dexmedetomidine, or ITM. The primary outcome was plasma matrix metalloproteinase-9 (MMP-9) concentration at 1 hour postoperatively. Secondary outcomes included other metastasis-promoting biomarkers (MMP-2, VEGF, IL-6), immune cell subsets (T and NK cells), and CD39/CD73 expression on T lymphocytes at 1 hour postoperatively and postoperative day 1. Clinical outcomes-including pain scores, opioid consumption, and complications-were also assessed.

RESULTS: Of the 114 enrolled patients, 109 completed the study and were analyzed (ITM group = 37, DEX group = 34, LIDO group = 38). Overall group × time interaction was significant for MMP-9 (P = .028). At 1 hour, MMP-9 was higher in LIDO group than in the DEX group (difference on the log scale, 0.333; 95% confidence interval [CI], 0.0642-0.601; P = .009) and in the ITM group (0.424; 95% CI, 0.0248-0.823; P = .033). The DEX group was associated with increased CD73+CD8+ T cells compared with the LIDO group (difference on the logit scale: 0.669; 95% CI, 0.000987-1.34; P = .050), and with decreased CD39-CD73-CD8+ T cells compared with the ITM group (-0.695; 95% CI, -1.3 to -0.0908, P = .018) and the LIDO group (-0.645; 95% CI, -1.24 to -0.05, P = .029). The ITM group was associated with lower dynamic pain scores than the other groups. Rescue antiemetic use was less frequent with the DEX group, whereas other adverse events were mild and comparable across groups.

CONCLUSIONS: Anesthetic adjuvants exerted differential effects on perioperative biomarkers and immune profiles relevant to tumor progression. Compared with the other groups, lidocaine was associated with higher MMP-9 levels, dexmedetomidine with relative shifts toward an immunosuppressive T-cell phenotype, and intrathecal morphine with superior analgesia with minimal immune impact. Further studies are warranted to determine whether multimodal analgesia strategies influence long-term oncologic outcomes.

PMID:42228944 | DOI:10.1213/ANE.0000000000007978

J Med Internet Res. 2026 Jun 2;28:e86498. doi: 10.2196/86498.

ABSTRACT

BACKGROUND: Large language models (LLMs) require specialized methodologies to quantify model confidence for safe deployment in health care systems; however, there is a lack of established methods for confidence assessment.

OBJECTIVE: This study aimed to evaluate confidence metrics for multimodal LLMs interpreting ultrasound-based radiology cases and to compare self-reported, consistency-based, and hybrid methods.

METHODS: From a total of 330 quizzes on the Korean Society of Ultrasound in Medicine digital platform, we selected 94 multiple-choice cases. Four multimodal LLMs were evaluated: 3 reasoning models (GPT-5, Claude-4.5-Sonnet, and Gemini-3-Pro) and 1 general model (GPT-4o). Temperature was fixed at 1.0. Multiple confidence metrics were assessed: (1) self-reported metrics generated by LLMs using prompts that elicited direct confidence percentages with answers, including first self-reported confidence and mean self-reported confidence; (2) consistency-based metrics derived from 20 repeated outputs per case, including relative entropy calculated as 1 – H/log2 k (H=Shannon entropy, k=number of answer choices) and majority-vote percentage; and (3) a Top Weighted Score combining response frequency with self-reported confidence. Receiver operating characteristic analysis for discrimination and Spearman correlation between accuracy and each confidence metric was conducted. Additionally, model calibration was assessed using expected calibration error and Brier score. Processing time and token consumption (input, output, and total) were recorded for each application programming interface call to evaluate resource use across models.

RESULTS: Diagnostic accuracy varied across models, with Gemini-3-Pro achieving the highest accuracy (70/94, 74.47%), surpassing the median human accuracy (59%, IQR 40.3%-75%). Top Weighted Score, a hybrid metric combining response frequency and self-reported confidence, was the only metric achieving statistically significant correlations across all 4 models: Gemini-3-Pro (ρ=0.52), GPT-5 (ρ=0.43), Claude-4.5-Sonnet (ρ=0.30), and GPT-4o (ρ=0.22). Receiver operating characteristic analysis revealed that Top Weighted Score demonstrated the highest discriminative ability, with area under the curve values of 0.826 (95% CI 0.731-0.920) for Gemini-3-Pro and 0.767 (95% CI 0.668-0.866) for GPT-5. Top Weighted Score was the only metric achieving statistical significance in GPT-4o. Calibration analysis showed that Top Weighted Score achieved the lowest expected calibration error in GPT-5 (0.098) and Claude-4.5-Sonnet (0.192), while Gemini-3-Pro showed comparable calibration between relative entropy (0.119) and Top Weighted Score (0.122). Resource use analysis demonstrated that reasoning models required substantially longer processing times and higher token consumption compared to general models.

CONCLUSIONS: In multimodal LLMs applied to ultrasound-based radiology cases, hybrid methods (Top Weighted Score) demonstrated significant associations across all evaluated models and appear to serve as more reliable indicators of diagnostic confidence compared to self-reported or consistency-based metrics alone, although the strength of these associations varied across models, and external validation is warranted before broader clinical application. These findings support integrative confidence estimation approaches that incorporate response consistency while highlighting the need for resource-efficient sampling strategies to enable practical clinical deployment.

PMID:42228942 | DOI:10.2196/86498