Tag: statistics

Int J Radiat Oncol Biol Phys. 2024 May 24:S0360-3016(24)00671-0. doi: 10.1016/j.ijrobp.2024.05.013. Online ahead of print.

ABSTRACT

INTRODUCTION: Cardiac substructure dose metrics are more strongly linked to late cardiac morbidities than whole-heart metrics. MR-guided radiation therapy (MRgRT) enables substructure visualization during daily localization, allowing potential for enhanced cardiac sparing. We extend a publicly available state-of-the-art deep learning (DL) framework, nnU-Net, to incorporate self-distillation (nnU-Net.wSD) for substructure segmentation for MRgRT.

METHODS: Eighteen (Institute A) patients who underwent thoracic or abdominal radiation therapy on a 0.35 T MR-guided linac were retrospectively evaluated. On each image, one of two radiation oncologists delineated reference contours of 12 cardiac substructures (chambers, great vessels, and coronary arteries) used to train (n=10), validate (n=3), and test (n=5) nnU-Net.wSD leveraging a teacher-student network and comparing to standard 3D U-Net. The impact of using simulation data or including 3-4 daily images for augmentation during training was evaluated for nnU-Net.wSD. Geometric metrics (Dice similarity coefficient (DSC), mean distance to agreement (MDA), and 95% Hausdorff distance (HD95)), visual inspection, and clinical dose volume histograms (DVHs) were evaluated. To determine generalizability, Institute A’s model was tested on an unlabeled dataset from Institute B (n=22) and evaluated via consensus scoring and volume comparisons.

RESULTS: nnU-Net.wSD yielded a DSC (reported mean ± standard deviation) of 0.65±0.25 across the 12 substructures (Chambers: 0.85±0.05, Great Vessels: 0.67±0.19, and Coronary Arteries 0.33±0.16, mean MDA <3 mm, and mean HD95 <9 mm) while outperforming the 3D U-Net (0.583±0.28, p<0.01). Leveraging fractionated data for augmentation improved over a single MR-SIM timepoint (0.579±0.29, p<0.01). Predicted contours yielded DVHs that closely matched the clinical treatment plans where mean and D_0.03cc doses deviated by 0.32±0.5 Gy and 1.42±2.6 Gy respectively. No statistically significant differences between Institute A and B volumes (p>0.05) for 11 of 12 substructures with larger volumes requiring minor changes and coronary arteries exhibiting more variability.

CONCLUSIONS: This work is a critical step to rapid and reliable cardiac substructure segmentation to improve cardiac sparing in low-field MRgRT.

PMID:38797498 | DOI:10.1016/j.ijrobp.2024.05.013

Radiother Oncol. 2024 May 24:110340. doi: 10.1016/j.radonc.2024.110340. Online ahead of print.

ABSTRACT

PURPOSE: This study aimed to reveal the association of fatigue with weekly changes in the body composition in patients with nasopharyngeal carcinoma (NPC) and identified the independent strength.

METHODS: Four body composition indexes and fatigue were assessed before treatment (T0, baseline) and once a week throughout radiotherapy (T1-T7). Generalized additive mixed models (GAMMs) were used to explore the trajectories and longitudinal relationships of fatigue and weekly changes in body composition. The marginal structural model (MSM) was used to control the effect of depression and anxiety.

RESULTS: The trajectories of fatigue in 105 participants reached a peak in the fifth week, and changes in body composition started appearing from the second week. Four body composition indexes, weight, body mass index (BMI), body fat rate, and lean body weight loss weekly were positively associated with fatigue. High magnitude of effects was revealed when anxiety and depression were controlled as time-dependent confounders. The positive associations with fatigue were manifested in patients aged >53 years, those with senior high and above education, no drinking, >5000 Y/month of family inflow, ≥ stage III, or those receiving a dose of ≥70 Gy, ≥3 cycles of induced chemotherapy, and ≤1 cycle of concurrent chemotherapy (CCRT).

CONCLUSIONS: Loss of weight, BMI, body fat rate, and lean body weight could be used to independently evaluate the development of fatigue in patients with NPC during radiotherapy. Positive associations between fatigue and weekly body composition loss were found in patients with certain characteristics.

PMID:38797492 | DOI:10.1016/j.radonc.2024.110340

J Dent. 2024 May 24:105098. doi: 10.1016/j.jdent.2024.105098. Online ahead of print.

ABSTRACT

OBJECTIVES: This study aimed to assess the clinical outcomes of utilizing silver diamine fluoride+potassium iodide (SDF+KI) treatment and Silver-Modified Atraumatic Restorative Technique (SMART/SDF+KI+Glass Ionomer Cement) over a three-year period on hypomineralised permanent molars with initial carious lesions.

METHODS: 112 hypomineralised permanent molars with ICDAS 1 or 2 lesions were selected in 48 children. The teeth were randomized into SDF+KI and SMART(SDF+KI+GIC) groups (n=56 teeth/group) in a split-mouth design. Hypersensitivity and caries development were evaluated in both groups. Schiff Cold Air Sensitivity Scale (SCASS) was used for evaluation of hypersensitivity, and the modified USPHS criteria were utilised for clinical assessments of SMART sealants at 1,6,12,18,24 and 36 months. Fisher’s Exact test, Kaplan-Meier Survival Curves, Log-rank test, Mann Whitney U test, and Friedman test was performed for the statistical analysis.

RESULTS: The caries preventive effect was 100%, 67.9% and 65.4% for SDF+KI-treated teeth; and 100%, 97.6% and 94.7% for SMART(SDF+KI+GIC)-treated teeth at 12, 24 and 36 months, respectively. The mean survival probabilities for caries-preventive effect were significantly lower in SDF+KI-treated teeth (31.01 months) than SMART-treated teeth (35.61 months),(p<0.001). Twenty-six molars with initial hypersensitivity due to hypomineralization demonstrated a significant reduction in baseline SCASS scores at all evaluation periods(p<0.001). Additionally, there was no significant difference in hypersensitivity scores between the groups, and by the 18-month follow-up, none of the teeth exhibited hypersensitivity.

CONCLUSIONS: During the three-year assessment, both groups demonstrated effectiveness in reducing sensitivity in hypomineralised molars. However, SMART(SDF+KI+GIC) sealants offered better protection against tooth decay over time, despite experiencing gradual retention loss.

CLINICAL SIGNIFICANCE: Both SMART(SDF+KI+GIC) sealants and SDF+KI proved effective in alleviating hypersensitivity in hypomineralised molars for up to three years. SMART(SDF+KI+GIC) sealants showed greater caries-preventive effect compared to SDF+KI. However, continuous long-term monitoring is crucial due to the gradual decline in retention of SMART(SDF+KI+GIC) sealants.

PMID:38797490 | DOI:10.1016/j.jdent.2024.105098

J Dent. 2024 May 24:105091. doi: 10.1016/j.jdent.2024.105091. Online ahead of print.

ABSTRACT

OBJECTIVES: Effectively assessing dental students’ knowledge and skills is an important part of their education. Assessment techniques available to teachers, have become more diverse as new technologies are introduced. This study aimed to investigate what dental educators thought about current and future assessment techniques.

METHODS: This was a mixed method study; quantitative data being collected at an annual dental educators’ conference, via on-screen questions requesting: i) demographic information; ii) type of student assessment currently used; iii) impact of Covid-19 on student assessment, and iv) future perceptions of assessment. Questions were posed in real time using the ‘Vevox’ platform. Descriptive statistical analysis was employed. Qualitative data were collected on ‘post-its’ and analysed thematically.

RESULTS: 101 participants attended the study. 59.1% (n=60) had >11 years’ experience. 64% (n=55) considered their summative and formative assessments were effective in developing student learning. Few participants reported students’ involvement in creating their own assessments (n=8; 9.75%). 41.68% (n=36) participants agreed it was a good idea for students to be involved in developing assessments, but only 9.75% (n=8) reported it was already happening. Qualitative data indicated a reluctance to wholeheartedly embrace technology (including AI) when planning assessments. Most participants were not in favours of Co-creation or the use of some technologies.

CONCLUSIONS: Participants, reflected on the challenges of adopting a universal assessment approach. Dental educators should be given the institutional support and autonomy to implement the best assessment methods for their students. Most of this cohort of experienced dental educators reported that assessments facilitated student learning.

CLINICAL SIGNIFICANCE: The role of assessment for dental students is essential as dental educators must ensure that dental students graduate with appropriate knowledge and technical skills to be safe when in general dental practice. The use of various assessment techniques needs to reflect the diversity of skills the students need to demonstrate.

PMID:38797487 | DOI:10.1016/j.jdent.2024.105091

J Adv Res. 2024 May 24:S2090-1232(24)00214-5. doi: 10.1016/j.jare.2024.05.025. Online ahead of print.

ABSTRACT

INTRODUCTION: Residential greenness may influence COPD mortality, but the causal links, risk trajectories, and mediation pathways between them remain poorly understood.

OBJECTIVES: We aim to comprehensively identify the potential causal links, characterize the dynamic progression of hospitalization or posthospital risk, and quantify mediation effects between greenness and COPD.

METHODS: This study was conducted using a community-based cohort enrolling individuals aged ≥ 18 years in southern China from January 1, 2009 to December 31, 2015. Greenness was characterized by normalized difference vegetation index (NDVI) around participants’ residential addresses. We applied doubly robust Cox proportional hazards model, multi-state model, and multiple mediation method, to investigate the potential causal links, risk trajectories among baseline, COPD hospitalization, first readmission due to COPD or COPD-related complications, and all-cause death, as well as the multiple mediation pathways (particulate matter [PM], temperature, body mass index [BMI] and physical activity) connecting greenness exposure to COPD mortality.

RESULTS: Our final analysis included 581,785 participants (52.52% female. average age: 48.36 [Standard Deviation (SD): 17.56]). Each interquartile range (IQR: 0.06) increase in NDVI was associated with a reduced COPD mortality risk, yielding a hazard ratio (HR) of 0.88 (95 % CI: 0.81, 0.96). Furthermore, we observed per IQR (0.04) increase in NDVI was inversely associated with the risk of multiple transitions (baseline – COPD hospitalization, baseline – death, and readmission – death risks), especially a declined risk of all-cause death after readmission (HR = 0.66 [95 %CI: 0.44, 0.99]). Within the observed association between greenness and COPD mortality, three mediators were identified, namely PM, temperature, and BMI (HR for the total indirect effect: 0.773 [95 % CI: 0.703, 0.851]), with PM showing the highest mediating effect.

CONCLUSIONS: Our findings revealed greenness may be a beneficial factor for COPD morbidity, prognosis, and mortality. This protective effect is primarily attributed to the reduction in PM concentration.

PMID:38797475 | DOI:10.1016/j.jare.2024.05.025

Math Biosci. 2024 May 24:109220. doi: 10.1016/j.mbs.2024.109220. Online ahead of print.

ABSTRACT

Ecological balance and stable economic development are crucial for the fishery. This study proposes a predator-prey system for marine communities, where the growth of predators follows the Allee effect and takes into account the rapid fluctuations in resource prices caused by supply and demand. The system predicts the existence of catastrophic equilibrium, which may lead to the extinction of prey, consequently leading to the extinction of predators, but fishing efforts remain high. Marine protected areas are established near fishing areas to avoid such situations. Fish migrate rapidly between these two areas and are only harvested in the nonprotected areas. A three-dimensional simplified model is derived by applying variable aggregation to describe the variation of global variables on a slow time scale. To seek conditions to avoid species extinction and maintain sustainable fishing activities, the existence of positive equilibrium points and their local stability are explored based on the simplified model. Moreover, the long-term impact of establishing marine protected areas and levying taxes based on unit catch on fishery dynamics is studied, and the optimal tax policy is obtained by applying Pontryagin’s maximum principle. The theoretical analysis and numerical examples of this study demonstrate the comprehensive effectiveness of increasing the proportion of marine protected areas and controlling taxes on the sustainable development of fishery.

PMID:38797471 | DOI:10.1016/j.mbs.2024.109220

J Shoulder Elbow Surg. 2024 May 24:S1058-2746(24)00355-0. doi: 10.1016/j.jse.2024.03.056. Online ahead of print.

ABSTRACT

BACKGROUND: Rotator cuff tears are a common orthopedic injury and the role of social determinants of health (SDoH) in surgical outcomes remains underexplored. The goal of this study was to investigate the correlation between social deprivation, measured by the Area Deprivation Index (ADI), and outcomes following arthroscopic rotator cuff repair.

METHODS: We conducted a retrospective chart review on patients undergoing primary arthroscopic rotator cuff repair at a level one academic center between 2006 and 2019. Patient demographics (age, gender, race), comorbidities, ADI scores, range of motion, visual analog pain scores, and patient-reported outcomes (SST, ASES, and QuickDASH) were collected. Patients were stratified into terciles based on their relative level of deprivation. Statistical analysis was performed using ANOVA, t-tests, chi-square tests, and univariate/multivariate logistic regression.

RESULTS: 322 patients were included in this study. The most deprived group had a higher prevalence of diabetes compared to the least and intermediately deprived group (p<0.001). Massive tear occurrence was greater in the least deprived group (p=0.003) compared to the most deprived group. There was no difference in objective outcomes between groups. Patient-reported outcomes (SST, ASES, and QuickDASH) were worse in the most deprived group compared to the least and intermediate deprived groups.

CONCLUSION: Social deprivation significantly affects patient-reported outcomes in rotator cuff repair surgery. While clinician-reported outcomes were consistent, patients’ perceptions varied based on social determinants. Integrating SDoH considerations in orthopedic care is a promising next step in securing equitable approaches. However, more research is needed to validate and expand these findings.

PMID:38797469 | DOI:10.1016/j.jse.2024.03.056

J Arthroplasty. 2024 May 24:S0883-5403(24)00525-4. doi: 10.1016/j.arth.2024.05.053. Online ahead of print.

ABSTRACT

INTRODUCTION: Venous thromboembolism (VTE) poses a major clinical concern due to its life-threatening nature, and obese and morbidly obese patients are thought to be at an increased risk for VTE. The aims of this study were twofold; first, to explore VTE rates in patients who have a body mass index > 40 undergoing primary and revision total joint arthroplasty (TJA), and second, to investigate aspirin (ASA) efficacy and safety.

METHODS: We identified all patients (n = 4,672) who had a BMI > 40 who underwent primary and revision TJA from 2016 to 2022 at a single academic tertiary care center. Patients were stratified by BMI groups: 40 to 44.9 (n = 3,462), 45 to 49.9 (n = 935), and 50+ (n = 275). The primary outcome was any venous thromboembolism (VTE) event within 90 days postoperatively. The secondary outcome consisted of wound complications within 90 days postoperatively.

RESULTS: The total VTE rate was 0.4% (n = 21) and did not differ statistically between the BMI groups (0.4 versus 0.4 versus 0.7%, P = 0.669). The VTEs consisted of six deep venous thromboses (DVT), fourteen pulmonary embolisms (PE), and one concomitant DVT and PE. The VTE rates were not statistically different between patients who received aspirin 325 mg 0.5% (n = 9), aspirin 81 mg 0.2% (n = 1), aspirin + anticoagulant 0.5% (n = 6), and anticoagulant alone 0.4% (n = 5) (P = 0.954). In addition, wound complications did not differ significantly between patients who received ASA 325 mg, ASA 81mg, ASA + anticoagulant, or anticoagulant alone (1.6 versus 1.0 versus 1.8 versus 1.1%, P = 0.351).

CONCLUSION: The use of aspirin 325 mg and 81 mg was found to have similar VTE rates as aspirin + anticoagulants and anticoagulants alone, with no significant increase in wound complications. In patients who have a BMI > 40, the use of aspirin is a safe option for VTE prophylaxis and should be prescribed in the context of the patient who has other risk factors for VTE.

PMID:38797448 | DOI:10.1016/j.arth.2024.05.053

Sci Total Environ. 2024 May 24:173524. doi: 10.1016/j.scitotenv.2024.173524. Online ahead of print.

ABSTRACT

Understanding the relationships among ecosystem services (ESs) and their interactions with influencing factors is essential for spatially targeted ecosystem governance. However, classifying the spatial distribution of these diverse interactions still needs improvement. Furthermore, existing studies have insufficiently addressed the specific impacts of bidirectional land cover transitions on ESs. Taking the upper Blue Nile basin as a study area, we estimated the spatiotemporal distribution of annual water yield (AWY), carbon storage (CS), habitat quality (HQ), and soil retention (SR) from 2000 to 2020, using InVEST models and associated formulas. Changes in ESs per inward-outward land cover transition were quantified based on the Cross-Tabulation Matrix. An improved pairwise method was employed to assess the spatially diverse interactions between ESs pairs and their relationship with influencing factors. The statistical significance of influencing factors was evaluated using partial least square regression. The findings indicated that high HQ values were prevalent in the west, while they were in the east for SR. The central and southern areas experienced higher CS and AWY values. During the study period, variations were observed in the mean values of SR (ranging from 22.89 to 23.88 × 10² t/ha/y), AWY (32.13-42.2 × 10² mm/ha/y), CS (90.5-102.9 × 10³gC/ha/y) and HQ (0.62-0.64). Synergies were predominant in AWY-CS, AWY-SR, and CS-SR pairs. HQ revealed more of a no-effect and tradeoff relationship with other ESs. The interactions between ESs and influencing factors were dominated by synergies, followed by tradeoffs and no-effect. The influence of landscape structure (gyrate and landscape shape index) and land surface temperature on all ESs and precipitation on AWY and SR was significant (1.049 ≤ Variable Importance in the Projection ≤ 1.371). Overall, the spatiotemporal dynamics of key ESs and the modeling of their drivers are essential policy information for taking spatially explicit conservation measures. This study will also serve as a valuable methodological reference for future research.

PMID:38797426 | DOI:10.1016/j.scitotenv.2024.173524

Sci Total Environ. 2024 May 24:173337. doi: 10.1016/j.scitotenv.2024.173337. Online ahead of print.

ABSTRACT

The intricate oceanic climate interactions with terrestrial primary production of Asian ecosystems exert crucial social-economical-environmental repercussions. Yet, a holistic understanding of tropical sea surface temperature (SST) anomalies associated with the gross primary productivity (GPP) variations of monsoon-Asia remains constrained. This study provides a statistical framework demonstrating how SST perturbations in the tropics influence GPP fluctuations in monsoon-Asia by modulating hydrothermal conditions of different climate system components. Observation evidence explicitly illustrated the characteristic anomalous SST signatures of positive and negative GPP anomalies in South and Southeast Asia during June-August. The SST anomalies of the central-eastern tropical Pacific showed a robust negative impact on the GPP variability of South-Asia. The GPP alterations in maritime-Southeast-Asia exhibited strong connections with SST anomalies of the western Pacific (positive) and eastern equatorial Pacific (negative). The oceanic signals in the GPP variability of South-Asia and maritime-Southeast-Asia mirrored canonical El Niño and La Niña patterns. The detected SST-GPP link is feasible through large-scale atmospheric circulation variability and the consequent regional modulation of heat and moisture fluxes. The anomalous strengthening (weakening) of Walker cell enhance (reduce) water available to plants for photosynthesis during La Niña (El Niño) phase of ENSO cycle and thus elevate (lower) GPP in South-Asia and Maritime-southeast-Asia. In contrast, the enhanced GPP anomaly in mainland-Southeast-Asia depicts signs of canonical La Niña and Indian Ocean subtropical dipole (IOSD) teleconnections. The positive impact of IOSD was through the modulation of the Mascarene High and the consequent impact on monsoon. Meanwhile, decreased GPP bears the imprint of El Niño Modoki and warm tropical Indian Ocean SSTs. The atmospheric teleconnections demonstrated the delayed impact of El Niño Modoki on GPP variability through the Indian Ocean capacitor effect. Our findings could be instrumental in forecasting the probable effects on vegetation growth in monsoon-Asia associated with high-frequency tropical oceanic changes.

PMID:38797406 | DOI:10.1016/j.scitotenv.2024.173337