Category: Statistics

PeerJ. 2026 Jul 29;14:e21545. doi: 10.7717/peerj.21545. eCollection 2026.

ABSTRACT

BACKGROUND: Protein supplements have gained popularity among gym users in Saudi Arabia. This study aimed to collect data from adults in Saudi Arabia focusing on six components related to protein supplements: demographic characteristics of participants, health and physical activity information, knowledge and attitudes, use, health beliefs, and safety concerns.

METHOD: This study was a cross-sectional, observational online survey targeting adults in Saudi Arabia. Participants included males and females aged 18 and older. Participants who did not complete the survey, as well as pregnant or breastfeeding women, were excluded. Ethical approval was obtained from the Deanship of Scientific Research at Qassim University. Data were analyzed by gender using SPSS version 25, with descriptive statistics and chi-square tests. A total of 358 participants completed the online questionnaire, while two participants did not complete it between March 29, 2024 and December 31, 2024.

RESULT: Regarding knowledge and attitudes, about 68.2% of participants (including both users and non-users of protein supplements) were aware of protein supplements, with males (81.3%) showing significantly higher awareness than females (63.7%). Additionally, 64.8% of participants (both male and female) were unaware of the risks associated with protein supplements. Of all participants, 56% of males and 39.3% of females did not believe that natural protein sources are enough for muscle building, indicating a significant difference. About 127 participants (35.5%) reported using protein supplements either currently or in the past, with no significant difference between males and females. Of those who reported using protein supplements, 11.8% experienced some side effects and were significantly less knowledgeable about the amount of protein they should consume from food and how much protein is enough for their needs. The majority of protein supplement users (48.8%) did not know if protein powders could contain doping agents, with females reporting significantly higher responses than males. Regarding safety concerns, only 43.3% of protein supplement users looked for protein supplements marked with NSF Certified for Sport^® on the package, with no significant difference between males and females. Finally, 78% of protein supplement users expressed a need for more information on how to select the best protein supplements, with the highest need found in females and participants who exercise regularly, who showed significantly higher needs for additional guidance.

CONCLUSIONS: There remains a significant need for increased education about the proper use of protein supplements to minimize potential side effects and increase understanding of their health risks and safety concerns.

PMID:42542879 | PMC:PMC13428538 | DOI:10.7717/peerj.21545

Cureus. 2026 Jul 1;18(7):e111896. doi: 10.7759/cureus.111896. eCollection 2026 Jul.

ABSTRACT

BACKGROUND: Orthodontic treatment involves the placement of appliances such as brackets, bands, and wires that are foreign objects within the oral cavity. These appliances, combined with the long treatment duration, can pose various physical and psychological challenges for patients. Understanding these challenges and assessing patient knowledge and attitudes may facilitate targeted patient education and improve treatment compliance.

METHODS: A cross-sectional questionnaire-based survey was conducted among 150 patients (aged 15-30 years) undergoing active orthodontic treatment. A structured, pre-validated 20-item questionnaire assessed treatment-related challenges, knowledge, and attitudes toward orthodontic treatment. Data were analyzed using descriptive statistics. Prevalence estimates with 95% confidence intervals (95% CIs) were calculated for all variables.

RESULTS: Food lodgment (54.7%; 95% CI: 46.7%-62.6%) and pain (53.3%; 95% CI: 45.3%-61.3%) were the most frequently reported challenges. Posterior bracket breakage (73.3%) was more frequently reported than anterior bracket breakage (26.7%). The majority of patients demonstrated a positive attitude: 93.3% took extra care in brushing, 86.7% were aware of the need for retainers, and 95.3% would recommend orthodontic treatment to others. Overall treatment satisfaction was high, with 90.6% rating their experience as good or very good.

CONCLUSION: Food lodgment, pain, and oral ulcers were the most prevalent challenges during orthodontic treatment. Despite these difficulties, patients displayed good knowledge and a positive attitude toward their treatment, highlighting the effectiveness of patient education and counseling.

PMID:42542876 | PMC:PMC13428491 | DOI:10.7759/cureus.111896

Clin Interv Aging. 2026 Jul 28;21:607805. doi: 10.2147/CIA.S607805. eCollection 2026.

ABSTRACT

BACKGROUND: Older adults with atrial fibrillation (AF)-associated acute ischemic stroke are prone to disability, depressive symptoms, and falls; the prognostic value of vitamin D status is uncertain.

METHODS: We conducted a single-center prospective cohort study of patients aged ≥65 years with ECG-confirmed AF and imaging-confirmed acute ischemic stroke at a tertiary hospital in China (January 2022-August 2024). Serum 25-hydroxyvitamin D [25(OH)D] within 48 hours was modeled per 10 ng/mL decrement and as <20 vs ≥20 ng/mL. Outcomes were 3-month modified Rankin Scale (mRS) shift, Barthel Index (BI), and PHQ-9 ≥10, plus 12-month time to first fall (death as a competing event) and total falls rate. Models adjusted for prespecified baseline confounders.

RESULTS: Among 802 participants, median age was 76.2 years (IQR, 71.6-80.6); 60.7% had 25(OH)D <20 ng/mL. Three-month mRS/BI, 3-month PHQ-9, and falls follow-up data were available for 776 (96.8%), 762 (95.0%), and 742 (92.5%) participants, respectively. Each 10 ng/mL lower 25(OH)D was associated with worse 3-month mRS shift (common OR 1.17, 95% CI 1.05-1.31) and lower BI (β -3.9, 95% CI -6.2 to -1.6). Depressive symptoms occurred in 16.8% and were more common with 25(OH)D <20 ng/mL (OR 1.54, 95% CI 1.07-2.22). Among 742 with falls follow-up, low 25(OH)D predicted first fall (HR 1.29, 95% CI 1.07-1.55) and a higher recurrent falls rate (IRR 1.33, 95% CI 1.10-1.61).

CONCLUSION: Lower baseline 25(OH)D was consistently associated with poorer functional recovery, greater depressive symptom burden, and higher fall risk and recurrence, supporting 25(OH)D as a pragmatic prognostic marker; multicenter validation and targeted trials are warranted.

PMID:42542873 | PMC:PMC13428550 | DOI:10.2147/CIA.S607805

Environ Geochem Health. 2026 Aug 1;48(12):500. doi: 10.1007/s10653-026-03401-7.

ABSTRACT

This study evaluated the radioactivity levels and associated radiological health risks of groundwater surrounding a coal-based super thermal power plant in Jhajjar district, Haryana, India. A total of seventy groundwater samples were gathered from thirty-five locations within a 20 km radius, along with five background sites located beyond that distance and were analysed for ⁴⁰K, ²³⁸U, and ²³²Th using a Sodium Iodide, Thallium-activated (NaI (Tl)) scintillation detector. The activity concentrations in the 20 km area varied from 0.11 to 37.72 Bq/L for ⁴⁰K (with an average of 8.14 ± 0.37 Bq/L), 0.01 to 3.13 Bq/L for ²³⁸U (average 0.82 ± 0.07 Bq/L), and 0.01 to 3.52 Bq/L for ²³²Th (average 0.45 ± 0.04 Bq/L). These levels were notably higher than the regional background levels measured beyond 20 km. The Annual Effective Dose and the Excess Lifetime Cancer Risk derived from radiological parameters showed the variation from 0.047 to 0.489 mSv y⁻¹, and 1.64 × 10⁻⁴ to 17.12 × 10⁻⁴ respectively. Approximately 60% of the groundwater samples exceeded the WHO (2017) guideline value for uranium (²³⁸U; 0.5 Bq/L), while about 40% exceeded the World Health Organization (WHO, 2017) reference level for Total Annual Effective Dose from drinking water (0.1 mSv y⁻¹). Furthermore, five sampling locations (W14, W17, W 18, W19 and W21) exceeded the International Commission on Radiological Protection (ICRP, 2007) benchmark for Excess Lifetime Cancer Risk (1 × 10⁻³). The elevated radionuclide concentrations within the 20 km radius were likely influenced by fly ash dispersion from the thermal power plant, as inferred from spatial, statistical, and wind-direction patterns, in addition to natural contributions from the regional geology. These results set a quantitative radiological baseline for the study area and showed how important it is to regularly check the groundwater to make sure it meets international radiological safety standards.

PMID:42542540 | DOI:10.1007/s10653-026-03401-7

Eye (Lond). 2026 Aug 1. doi: 10.1038/s41433-026-04781-x. Online ahead of print.

ABSTRACT

BACKGROUND: To quantitatively assess the entrance angle variability and location of perforating scleral vessels (PSVs) in highly myopic eyes and to investigate its association with myopic choroidal neovascularisation (mCNV) versus lacquer cracks (LC).

METHODS: Entrance angles from the sclera to choroid were measured on each B-scan OCT using ImageJ and associated angle metrics were calculated per PSVs. Additional variables included subfoveal choroidal thickness (SFCT) and vessel-to-fovea distance (VFD). In mCNV eyes the total number of injections and treatment duration were also accounted.

RESULTS: A total of 42 eyes were included, 25 with mCNV and 17 with LC. Eyes with mCNV demonstrated significantly greater PSV angular variability including angular standard deviation, and their normalised metrics compared to LC eyes (all p < 0.001). VFD was shorter in the mCNV group (50.2 ± 52.6 µm vs. 91.5 ± 39.6 µm, p = 0.006). Normalised angle metrics correlated positively with the total number of anti-VEGF injections (r ≈ 0.37, p < 0.05), whereas no association was observed with treatment duration. In multivariable regression, no predictors reached statistical significance although normalised angle range (NAR) showed a trend toward a negative association with VFD (p = 0.060).

CONCLUSIONS: PSV angular variability was markedly greater in mCNV eyes and correlated with anti-VEGF injection burden reflecting higher treatment intensity but not longer disease duration. These findings suggest that PSV geometry influences LC and mCNV, may serve as an imaging biomarker of disease activity in mCNV. Shorter VFD and greater angular dispersion likely reflect structural and hemodynamic alterations predisposing to mCNV.

PMID:42542506 | DOI:10.1038/s41433-026-04781-x

Eur J Orthop Surg Traumatol. 2026 Aug 1;36(1):315. doi: 10.1007/s00590-026-04901-z.

ABSTRACT

INTRODUCTION: Early identification of patients at high risk of deep surgical site infection after open extremity fractures is crucial for timely intervention and improved outcomes. This study aimed to develop and internally validate a clinical prediction model, the BIGB²OSS score, for predicting deep surgical site infection within three months of injury using variables easily obtained in early post-injury phase.

METHODS: A prospective cohort study was conducted at two university hospitals in Japan, including 570 consecutive patients with open extremity fractures. Data on 18 candidate predictors were collected in the early post-injury phase. The primary outcome was the occurrence of deep surgical site infection within three months of injury. A backward stepwise logistic regression model was used to build the prediction model. Model performance was assessed using the area under the curve (AUC) and internal validation with bootstrap methods.

RESULTS: The BIGB²OSS score was a 5-point model based on four predictors: BMI ≥ 25 (1 point), Gustilo-Anderson classification IIIA (1 point), Gustilo-Anderson IIIB or IIIC (2 points), OTA-OFC skin = 3 (1 point), and smoking history (1 point). The model showed fair discriminative ability with an AUC of 0.76 (95% CI 0.70-0.83). Internal validation using bootstrap resampling with 1000 repetitions yielded an optimism-adjusted C-statistic of 0.76 (95% CI 0.70-0.83). The estimated probabilities of deep surgical site infection were 2.7% for scores 0-1, 11% for scores 2-3, and 30% for scores 4-5, closely matching the actual prevalence.

CONCLUSION: The BIGB²OSS score is a simple clinical prediction model with fair discrimination for deep surgical site infection in patients with open extremity fractures. It uses early post-injury variables and may support timely risk communication and follow-up planning. Further external validation is needed to confirm its utility in diverse clinical settings.

PMID:42542500 | DOI:10.1007/s00590-026-04901-z

Environ Monit Assess. 2026 Aug 1;198(8):900. doi: 10.1007/s10661-026-15759-3.

ABSTRACT

The Danjiangkou Reservoir is the drinking-water source of the South-to-North Water Diversion Middle Route and a national Class I drinking-water protection area. Ensuring low turbidity is essential for safeguarding downstream public health and national water security. However, turbidity retrieval in large inland reservoirs using remote sensing is often constrained by limited in situ samples and weak model generalization across seasons and years. We integrated 49 GaoFen-1 (GF-1) satellite images with in situ measurements from the national water quality network to construct a matchup dataset for model development and validation from 2020 to 2024. Using this matchup dataset, five modeling approaches were compared under a time-ordered validation framework to identify a suitable model for predicting in situ turbidity from GF-1 spectral features. Among them, the sparrow search algorithm (SSA)-optimized extreme gradient boosting (XGBoost) approach achieved the best performance and was selected for retrospective quarterly mapping from 2013 to 2024. Across 45 quarterly clear-sky scenes, 95.5% of all retrieved turbidity values were below 15 nephelometric turbidity units (NTU), while persistent spatial heterogeneity and recurrent inflow-zone hotspots remained evident. Scene-wise diagnostics indicated stable performance across acquisition dates, with per-scene mean absolute error (MAE) < 4 NTU for all 49 scenes and 61.2% of scenes falling within 0-2 NTU. Precipitation showed the clearest association with turbidity and exhibited a region-dependent lagged response within the 52-h pre-acquisition window, with the strongest response observed in the precipitation-sensitive zone about 28-51 h before image acquisition (r = 0.36). Water temperature showed a moderate negative relationship with turbidity (r = – 0.47). These results provide spatial evidence for long-term turbidity surveillance, recurrent hotspot identification, and post-storm monitoring in large source-water reservoirs.

PMID:42542499 | DOI:10.1007/s10661-026-15759-3

J Math Biol. 2026 Aug 1;93(2):29. doi: 10.1007/s00285-026-02428-9.

ABSTRACT

We study mechanisms and effects of ideal free distributions (IFDs) on an ecological community consisting of n prey and m predator species, for any positive integers n and m, by considering the corresponding diffusive Lotka-Volterra system with time-periodic coefficients. We define a notion of joint IFD in a time-periodic environment, and give necessary and sufficient conditions for it to be achieved by a subcollection of prey and predator species with suitable dispersal strategies. Next, we show, via construction of a Lyapunov functional, that such dispersal strategies are evolutionarily stable, in the sense that if a subcollection of prey and predator species adopts an ideal free dispersal strategy, then the total community must converge to an IFD for large time; if a unique combination of prey-predator species adopts an ideal free strategy, then it can drive all other species to extinction. Conversely, if a combination of prey-predator species adopts a non-ideal free dispersal strategy, then it can be invaded by some suitable mutant strategies. Our results provide insight into the evolution of spatial distribution of ecological communities with predator-prey interactions.

PMID:42542498 | DOI:10.1007/s00285-026-02428-9

Pain Ther. 2026 Aug 1. doi: 10.1007/s40122-026-00872-5. Online ahead of print.

ABSTRACT

INTRODUCTION: Persistent postoperative low back pain remains a concern after unilateral biportal endoscopic (UBE) surgery, but the impact of surgery-related interspinous ligament edema is unclear. This study investigated whether magnetic resonance imaging (MRI)-detected interspinous ligament region edema (ISLRE) was associated with delayed pain recovery and persistent postoperative low back pain after UBE surgery.

METHODS: This retrospective cohort study included patients who underwent single-level UBE surgery between October 2021 and October 2024. On the basis of MRI within 3 days postoperatively, ISLRE was graded as grade 0 (no/minimal edema), grade 1 (localized edema), or grade 2 (diffuse or confluent edema involving most of the operated interspinous region). Clinical outcomes included visual analogue scale scores for low back pain (VAS-LBP), Oswestry disability index (ODI), and persistent postoperative low back pain, defined as 12-month VAS-LBP > 3. Multivariable linear and logistic regression analyses were performed to assess independent associations, and linear mixed-effects modeling was used to evaluate longitudinal pain recovery trajectories.

RESULTS: A total of 245 patients were included (grade 0: n = 117; grade 1: n = 74; grade 2: n = 54). Interobserver agreement for MRI grading was substantial (κ = 0.802). At 12 months, VAS-LBP scores increased progressively across edema grades (1.66 ± 1.20, 2.34 ± 1.45, and 3.54 ± 1.65 for grades 0-2, respectively; P < 0.001), while persistent postoperative low back pain occurred in 21.4%, 41.9%, and 68.5% of patients, respectively (P < 0.001). Compared with grade 0 edema, grade 2 edema was independently associated with higher 12-month pain scores (β = 1.78, 95% confidence interval [CI] 1.34-2.22; P < 0.001) and more than eightfold increased odds of persistent postoperative low back pain (odds ratio [OR] 8.90, 95% CI 4.01-19.76; P < 0.001). Linear mixed-effects modeling demonstrated significantly delayed pain recovery trajectories in higher-grade edema groups. Although statistically significant, the magnitude of ODI differences at 12 months was below the minimal clinically important difference (MCID) threshold, suggesting limited clinical relevance.

CONCLUSIONS: The extent of postoperative ISLRE, particularly grade 2 edema, may be useful for postoperative risk stratification and targeted patient management after UBE surgery.

PMID:42542473 | DOI:10.1007/s40122-026-00872-5

Evid Based Dent. 2026 Aug 1. doi: 10.1038/s41432-026-01239-7. Online ahead of print.

ABSTRACT

A COMMENTARY ON: Awawdeh L, Almesleh B, Hammouri H, Al-Qudah A. The outcome of pulp revascularization of necrotic mature permanent teeth with periapical lesions using platelet-rich fibrin versus induced bleeding: a prospective preliminary randomized clinical trial. Clinical Oral Investigations. 2026; https://doi.org/10.1007/s00784-026-06877-w .

DESIGN: A single-centre, prospective, two-arm parallel randomised clinical trial presented as a preliminary (early-phase) investigation.

CASE SELECTION: Fifty adults presenting with mature permanent teeth where the pulpal status was diagnosed as necrotic with associated periapical lesions were included. The pool of patients was allocated to one of two regenerative endodontic treatment protocols, each containing 25 patients. In one group, 25 patients underwent a procedure where a canal scaffold was generated by deliberately provoking bleeding from the periapical tissues (induced bleeding, IB). In the second group of patients, an autologous platelet-rich fibrin (PRF) membrane was placed to serve as a biological barrier. A clinical and radiographic review was done at baseline, 6 months, and 12 months after treatment completion.

DATA ANALYSIS: Pre-specified endpoints were set to determine, firstly, tooth survival and overall treatment success and secondly, periradicular healing through radiographic evaluation. Within- and between-group comparisons were made using the appropriate statistical tests and statistical significance was set at p < 0.05.

RESULTS: At the one-year mark, 98% of teeth had survived (47/48). Interestingly, survival did not differ meaningfully between the two treatment groups (p = 0.166). Both treatment options produced healing with a statistically significant reduction in periradicular pathology compared with baseline at the six- and twelve-month reviews (p < 0.001). Also, a statistically significant impact was found on the overall success rate at the endpoint (p = 0.022). In the IB group, a 100% success rate was achieved (23/23) compared to 75% in the PRF group (18/24), with a combined overall success of 85.4%.

CONCLUSIONS: Whichever treatment pathway was followed, all teeth survived the chosen regenerative endodontic procedure after 12 months. The preliminary results indicated that results and clinical outcomes were comparable. Although the IB option showed a higher overall success rate, this finding should be interpreted with caution as the results fall within the early phase clinical evidence framework. Further investigations are required to determine the superiority of one method over the other.

PMID:42542468 | DOI:10.1038/s41432-026-01239-7