Category: Statistics

BMC Oral Health. 2026 Jul 3. doi: 10.1186/s12903-026-08968-2. Online ahead of print.

ABSTRACT

OBJECTIVES: This in vitro study compared the shear bond strength (SBS) and failure mode of laser-sintered orthodontic metal specimens bonded to enamel using different bonding protocols (with or without enamel sandblasting and four adhesive systems).

METHODS: Two hundred and forty bovine teeth were randomly allocated to no sandblasting (control) or sandblasting (50 µm, 1 bar) and bonded with 3D-printed Co-Cr discs using either light-curing orthodontic adhesives (Transbond XT, Transbond LR) or dual-curing resin cements (RelyX Unicem 2 Automix, Panavia SA Cement Universal Automix) (2 × 4 design; n = 30/group). After SBS testing, the failure mode was documented. Welch’s ANOVA was used to compare SBS across groups (S, C, and subgroups); p < 0.05 was considered significant.

RESULTS: Dual-curing adhesives (RX, PA) showed higher SBS than light-curing adhesives (XT, LR) (p = 0.001). The highest SBS was observed in RX (33 MPa), and the lowest in XT (18 MPa). A surface treatment × adhesive effect was found, although not statistically significant (p = 0.21). Failures occurred mainly on the metal side (> 50%; 140/240).

CONCLUSIONS: Dual-curing adhesives showed higher SBS when bonding laser-sintered Co-Cr appliances to bovine enamel, with failures predominantly occurring on the metal side. Sandblasting of enamel did not increase SBS under the conditions tested. As SBS values exceeded the clinically acceptable range, additional enamel sandblasting may not be clinically necessary.

CLINICAL SIGNIFICANCE: For bonding laser-sintered Co-Cr appliances, dual-curing adhesives may provide clinically acceptable SBS, but higher values could increase enamel damage risk during debonding. Enamel sandblasting showed no SBS benefit in this protocol.

PMID:42399964 | DOI:10.1186/s12903-026-08968-2

J Transl Med. 2026 Jul 3. doi: 10.1186/s12967-026-08546-8. Online ahead of print.

ABSTRACT

BACKGROUND: Gynecologic cancers remain a substantial clinical challenge, particularly in advanced stages, where treatment options are often associated with limited efficacy and poor prognosis. Given the emerging success of HER2-targeted antibody-drug conjugates (ADCs) across solid tumors, accurate evaluation of HER2 status is essential. This study investigated intratumoral HER2 heterogeneity in gynecologic cancers to refine detection accuracy and improve patient stratification for targeted therapy.

METHODS: A retrospective cohort of 416 patients with gynecologic malignancies was analyzed using immunohistochemistry (IHC) testing on separate dual formalin-fixed paraffin-embedded (FFPE) tumor blocks. HER2 expression was scored according to ASCO/CAP gastric criteria, and heterogeneity was defined as discordant IHC scores across blocks. Statistical analyses were performed using McNemar’s test, and clinical predictors of discordance were identified through multivariate logistic regression.

RESULTS: Across all tumors, HER2 IHC scores were distributed as 0 (49.5%), 1+ (33.9%), 2+ (15.6%), and 3+ (1.0%). HER2 overexpression was most frequent in uterine serous carcinoma, uterine endometrioid carcinoma, and ovarian clear cell carcinoma in our cohort. Intratumoral discordance was observed in 20.7% of cases, with the highest rates in uterine (23.9%, 21/88), ovarian (21.4%, 39/182), and cervical (18.2%, 26/143) tumors. Dual-block assessment revealed that most discrepancies resulted from incremental shifts in HER2 expression, primarily from 0 to 1 + or 1 + to 2+. This approach reclassified 13.5% of tumors originally reported as HER2-0 to HER2 expression.

CONCLUSION: Intratumoral HER2 heterogeneity is common in gynecologic cancers and frequently results in underestimation of HER2 expression when single-block assessment is used. Dual-block evaluation improves detection sensitivity and may refine patient selection for HER2-targeted antibody-drug conjugates.

PMID:42399958 | DOI:10.1186/s12967-026-08546-8

Chiropr Man Therap. 2026 Jul 3. doi: 10.1186/s12998-026-00665-9. Online ahead of print.

ABSTRACT

BACKGROUND: The Imposter Phenomenon (IP)-doubting one’s abilities despite clear achievements-is well-documented among healthcare professionals but has never been studied among practicing chiropractors, who face unique challenges including professional isolation and ambiguous healthcare identity. This study aimed to determine IP prevalence among South African chiropractors and investigate associations with age, gender, years of experience, and province.

METHODS: A cross-sectional survey using the validated Clance Imposter Phenomenon Scale (CIPS) was distributed via email to all 960 chiropractors registered with the Allied Health Professions Council of South Africa. Data were collected online from 25 March to 17 May 2024. Descriptive statistics, independent-samples t-tests, and one-way ANOVA were used; results are interpreted through effect sizes (Cohen’s d) and 95% confidence intervals, with exact p-values reported as continuous evidence measures. Cronbach’s alpha assessed reliability. The study followed STROBE and CHERRIES guidelines.

RESULTS: Of 159 chiropractors (16.6% response rate), mean age was 37.8 years (SD = 10.8); 61.6% were female. Mean CIPS score was 50.78 (SD = 16.82), indicating moderate IP. Severity distribution: 33.3% few, 39.0% moderate, 22.6% frequent, 5.0% intense IP (66.6% at or above moderate threshold). Females scored higher than males (55.66 vs. 42.93; t(147.69)= – 5.25, p < 0.001; d = 0.85). Chiropractors ≤ 35 years scored higher than those > 35 years (53.52 vs. 47.95; t(152) = 2.05, p = 0.042; d = 0.33). Chiropractors with ≤ 10 years of experience showed a non-significant trend toward higher IP scores than those with > 10 years (52.90 vs. 47.94; two-tailed p = 0.066; d = 0.30). No provincial differences were found (F(3,155) = 0.62, p = 0.601). Cronbach’s α was 0.94.

CONCLUSIONS: Moderate to intense IP affects two-thirds of chiropractors in this South African sample, particularly females and early-career practitioners. These findings highlight the need for targeted mental health interventions, mentorship, and peer support. This first study of IP among practicing chiropractors provides evidence for practitioner well-being initiatives with implications for chiropractic education, professional development, and retention.

PMID:42399952 | DOI:10.1186/s12998-026-00665-9

BMC Med Educ. 2026 Jul 3;26(1):1070. doi: 10.1186/s12909-026-09247-y.

ABSTRACT

Early obstacles to career progression of women in surgery present a major challenge in a variety of surgical subspecialties. Although there is a variety of literature on the attitudes and needs of female residents and trainees to foster interest in a career as a surgeon, there is a lack of research about the perspectives of female medical students about a possible career as a surgeon. In this paper, we report the results of a multicentric study on the evolving needs of female medical students to consider a career as a surgeon in Germany. We confirm several results mentioned in the available literature on the topic, but also add novel insights, in particular, which attitudes and obstacles already shape earlier than during trainee programmes or residency, namely, during medical school. Our results indicate that a curriculum to foster interest in surgical careers has to incorporate three core ingredients: (1) Effective concepts against gender discrimination, (2) measures to work towards more flexible work times and better work-life-balance of female surgeons and (3) an increase in female role models and mentoring programmes, tailored specifically for female medical students.

PMID:42399949 | DOI:10.1186/s12909-026-09247-y

BMC Med. 2026 Jul 3. doi: 10.1186/s12916-026-05033-1. Online ahead of print.

ABSTRACT

BACKGROUND: Gestational diabetes mellitus (GDM) is a well-established risk factor for subsequent type 2 diabetes mellitus (T2DM). However, its long-term association with diabetic microvascular complications, particularly diabetic retinopathy (DR), and the joint role of polycystic ovary syndrome (PCOS) remain incompletely understood.

METHODS: Using the Korean National Health Insurance Service database, we conducted a nationwide retrospective cohort study including 406,309 women who had their index delivery between 2005 and 2012. Standard Cox proportional hazards models were used to evaluate the incidence of T2DM and systemic complications. For DR and vision-threatening DR (VTDR), time-varying covariate Cox models were applied in the full cohort, with incident T2DM treated as a time-dependent variable. Sensitivity analyses restricted to women who developed T2DM were also performed. Stratified analyses evaluated the joint and independent effects of coexisting PCOS.

RESULTS: During follow-up, women with prior GDM had a higher risk of developing T2DM (adjusted hazard ratio [aHR] 3.52; 95% CI 3.26-3.80). In time-varying analyses, prior GDM was associated with an increased risk of vision-threatening DR (VTDR) (aHR 2.28; 95% CI 1.06-4.92), whereas overall DR did not show a consistent positive association across analysis. Women with both GDM and PCOS had the highest risk of T2DM and VTDR compared with those with neither condition (aHR 4.96 and 31.90, respectively). In contrast, although some macrovascular outcomes showed statistically significant associations, the overall magnitude of risk increase was modest.

CONCLUSIONS: A history of GDM was associated with an increased long-term risk of severe diabetic retinal outcomes, particularly VTDR, after the onset of T2DM. The coexistence of PCOS is associated with a higher overall risk burden, with women having both conditions showing the highest risks. These findings support the need for individualized metabolic and ophthalmic surveillance in women with prior GDM, particularly those with coexisting PCOS.

PMID:42399945 | DOI:10.1186/s12916-026-05033-1

BMC Health Serv Res. 2026 Jul 3. doi: 10.1186/s12913-026-14905-4. Online ahead of print.

ABSTRACT

BACKGROUND: Effective pain management and safe opioid prescribing remain major challenges in healthcare delivery. Prior research demonstrates that clinicians often manage chronic pain with little or no formal training in pain management, contributing to low confidence and apprehension when prescribing opioids. Surveys also show that insufficient knowledge and inadequate preparation are among the most common barriers to adopting evidence-based opioid-prescribing practices. This study examined Clinicians’ beliefs, knowledge, and experiences regarding pain management and opioid prescribing at a large academic health system.

METHODS: A cross-sectional survey was administered to about 500 clinicians across multiple specialties including internal medicine, general pediatrics, surgery, family medicine and others at Loma Linda University Health (LLUH) in Spring 2018. A 54-item survey instrument developed primarily from existing medical and pharmacy education literature was used to assess clinicians’ beliefs, knowledge, and experiences related to pain management. Descriptive statistics summarized demographic and clinical characteristics. Independent t-tests and correlation analyses evaluated associations between clinicians’ beliefs, knowledge and experiences regarding pain management and opioid prescribing.

RESULTS: Of 262 surveys returned, 255 complete responses were included for a 51% response rate. Respondents averaged 8.3 years in clinical practice and worked approximately 48 h weekly. Only 34.6% reported receiving formal pain-management training. Most clinicians (76.1%) believed opioid misuse is a major community problem, and 71.4% agreed that medical education devotes insufficient time to pain-management topics. Confidence in opioid-related counseling was low; however, fewer than half felt adequately trained or knowledgeable to manage chronic pain safely. Clinicians with formal training reported significantly higher confidence in counseling about pain, opioid use, and opioid misuse (p < 0.001). Residents were more likely than attending physicians to view their institution’s pain-management resources positively, while attendings rated their own knowledge and training more favorably. Years of clinical experience correlated positively with perceived adequacy of training (r = 0.206, p = 0.001) and knowledge (r = 0.176, p = 0,006), but negatively with perceived need for more education on opioid misuse (r=-0.241, p < 0.001).

CONCLUSIONS: Within a single academic health system, pain management beliefs and perceived knowledge differed significantly between attending physicians and residents, underscoring the influence of training stage. Formal education emerged as a key determinant of preparedness, while persistent educational gaps highlight the need for system-level improvement. Addressing these challenges will require integrated strategies that combine targeted education, workflow-embedded supports, and institutional commitment to evidence-based, comprehensive pain care.

PMID:42399944 | DOI:10.1186/s12913-026-14905-4

BMC Oral Health. 2026 Jul 4. doi: 10.1186/s12903-026-09154-0. Online ahead of print.

ABSTRACT

OBJECTIVE: With the advancement of artificial intelligence (AI), large language models (LLMs) have become an alternative source of information in dentistry. These LLMs, which can be trained on large data sets, can answer medical questions and provide references, but they can pose problems in terms of ethics and accurate information. This research aims to evaluate the accuracy of five different LLMs in diagnosis and treatment planning in the field of restorative dentistry.

METHODOLOGY: The 20 most common cases encountered in a restorative dentistry clinic were formulated into questions. The validity of the questions was assessed using the Lawshe Content Validity Index. The questions were posed to five different LLMs: ChatGPT-5, Deepseek V3.2, Claude Sonnet 4.5, Microsoft Copilot, and Google Gemini 3 Flash. Each model was asked to create a diagnosis and treatment plan for each case. The responses were evaluated by 42 restorative dentistry specialists using a Likert Scale. Additionally, the accuracy of the references provided in the responses was evaluated by the article authors. The obtained data were analyzed using the non-parametric Kruskal-Wallis test, and the Dunn multiple comparison test was applied in cases where significant differences were detected.

RESULTS: Statistically significant differences were found between the models for 15 out of 20 questions (p < 0.05). A significant difference was also found in terms of total median scores (p < 0.001), with Google Gemini 3 Flash (median:83) and ChatGPT-5 (median:81) achieving the highest scores. Reference quality was evaluated using a four-category framework. Claude Sonnet 4.5 and Google Gemini 3 Flash demonstrated the highest proportions of accurate and relevant references (85.7% and 84.2%, respectively), while DeepSeek V3.2 exhibited the highest fabrication rate (55.6%).

CONCLUSIONS: Based on specialist-evaluated response quality, no model demonstrated consistent and superior performance across all clinical scenarios. LLMs appear to have potential as supplementary information resources for clinicians in restorative dentistry; however, their clinical integration, impact on patient outcomes, and real-world usability remain to be established in future research.

PMID:42399936 | DOI:10.1186/s12903-026-09154-0

BMC Oral Health. 2026 Jul 4. doi: 10.1186/s12903-026-09169-7. Online ahead of print.

ABSTRACT

BACKGROUND: COVID-19 shows marked variation in clinical severity. Identifying demographic and clinical factors associated with severity is particularly important in conflict-affected, resource-limited settings. This study assessed the relationship between COVID-19 symptom severity and selected variables, including sex, age, marital status, and dental plaque index, among patients in northwest Syria.

METHODS: This cross-sectional analytical study was conducted from 12 October to 23 November 2021 in three COVID-19 isolation centers in northwest Syria. Sixty adult patients with confirmed SARS-CoV-2 infection were enrolled through consecutive screening with purposive quota balancing by clinical severity category, resulting in 20 patients in each of the mild, moderate, and severe groups. Demographic data were recorded, and oral examination was performed by one trained examiner to assess plaque index using the modified Greene-Vermillion index. Associations were analyzed using Spearman’s rank correlation, Pearson correlation, Kruskal-Wallis H test, and chi-squared test, with statistical significance set at p ≤ 0.05.

RESULTS: The sample included 38 females (63.3%) and 22 males (36.7%), aged 18-82 years. COVID-19 severity was significantly associated with sex, with greater severity among males (Spearman’s ρ = – 0.428, p = 0.001). Age showed a weak but significant positive correlation with severity (Pearson’s r = 0.287, p = 0.026). Marital status was also associated with severity (Spearman’s ρ = 0.329, p = 0.010), although this relationship appeared to be strongly confounded by age. Dental plaque index showed a moderate positive association with COVID-19 severity (Spearman’s ρ = 0.533, 95% CI: 0.307-0.702; p < 0.001), indicating that higher plaque accumulation was associated with more severe symptoms.

CONCLUSION: In this conflict-affected humanitarian setting, male sex, older age, and higher dental plaque index were significantly associated with increased COVID-19 symptom severity. These findings are preliminary and should be interpreted cautiously because of the cross-sectional design, small sample size, and limited data on potential confounders. Nevertheless, the study contributes evidence from an underrepresented crisis-affected population and suggests that oral health assessment may have value as part of broader COVID-19 risk evaluation in resource-constrained settings.

PMID:42399931 | DOI:10.1186/s12903-026-09169-7

BMC Oral Health. 2026 Jul 3. doi: 10.1186/s12903-026-08864-9. Online ahead of print.

ABSTRACT

BACKGROUND: Oroantral communication (OAC) and its chronic form, oroantral fistula (OAF), are significant complications primarily associated with the extraction of maxillary posterior teeth. Delayed diagnosis or inadequate primary management often leads to persistent maxillary sinusitis and secondary morbidities. Despite their clinical relevance, there is a lack of evidence regarding the factors influencing dentists’ diagnostic accuracy and therapeutic decision-making. This study provided a nationwide evaluation of dentists’ objective knowledge, clinical approaches, and self-perceived competence regarding the management of OAC and OAF in Turkey.

METHODS: This nationwide cross-sectional study included 400 dentists, divided into two equal groups: 200 general dental practitioners (Group 1) and 200 participants in the oral and maxillofacial surgery group (Group 2). A structured 35-item questionnaire collected data on professional experience and OAC/OAF-related knowledge across three subdomains: general, diagnostic, and treatment-oriented. Furthermore, the survey assessed clinical referral thresholds and self-perceived educational and diagnostic competence using a specialized scale. Statistical analysis included comparative tests and multiple linear regression models to identify independent predictors of clinical knowledge levels.

RESULTS: Group 2 demonstrated significantly higher scores across all knowledge subdomains compared to Group 1 (p < 0.05), with mean total scores of 0.81 ± 0.08 and 0.57 ± 0.12, respectively. Significant disparities were observed in etiology, preoperative risk assessment, and radiographic interpretation. Group 1 exhibited a higher tendency toward referral-based management, while Group 2 more frequently performed direct clinical management. Multiple linear regression revealed that being in Group 2, prior postgraduate training, and previous clinical case experience were independent positive predictors of higher knowledge scores. Conversely, a lack of preference for specific closure materials was a negatively associated with overall knowledge.

CONCLUSIONS: Knowledge levels regarding OAC/OAF management were significantly associated with professional group and clinical exposure. While Group 2 showed higher overall proficiency, knowledge gaps were also identified in specific domains. Within the context of dental education and clinical practice in Turkey, these findings support the need for strengthened undergraduate and postgraduate educational approaches to improve preparedness for OAC/OAF management.

PMID:42399919 | DOI:10.1186/s12903-026-08864-9

BMC Med. 2026 Jul 3. doi: 10.1186/s12916-026-05009-1. Online ahead of print.

ABSTRACT

BACKGROUND: Leflunomide (LEF) shows promising effect in Takayasu arteritis (TAK), but evidence from randomized controlled trials is lacking. This study aims to investigate the efficacy and safety of LEF versus placebo combined with prednisone for the treatment of TAK.

METHODS: This is a multicenter, randomized, double-blind, placebo-controlled trial at six sites across China, conducting from December 22, 2016, to November 4, 2022. A total of 116 eligible patients were recruited and randomized 1:1 to receive LEF (20 mg/d, p.o.) or matched placebo for 24 weeks, with all patients having initial prednisone of 0.6 mg/kg/d and following a taper starting at week 4. By week 24, patients in the LEF group who did not achieve clinical remission discontinued the study; all other patients (both LEF and placebo groups) received LEF (20 mg/d) from week 25 to week 52. The primary outcome was clinical remission at week 24. Secondary outcomes were time-to-clinical remission, mean prednisone dose at week 24, clinical remission in those who switched to LEF from week 25, disease recurrence and time-to-recurrence, imaging changes, and safety.

RESULTS: Fifty-four and 57, 45 and 48 patients were included in LEF and placebo group of modified intention-to-treat (mITT) and per-protocol set (PPS). In mITT set, clinical remission was achieved in 44/54 (81.5%) LEF- and 45/57 (78.9%) placebo-treated patients (risk difference: 2.6, 95%CI: -12.5, 17.2) at week 24. The same trend was observed in the sensitivity analyses. Post hoc analyses indicated greater risk differences (LEF minus placebo) in the female subgroup, ≤ 40 years subgroup, refractory subgroup, systemic symptoms subgroup, imaging type II subgroup and in those achieving the composite endpoint of both clinical remission and stable/improved imaging. At week 24, LEF group had a lower mean prednisone dose (mean difference: -2.1, [-4.3, 0.1] mg/d). Adverse events were observed in 13 (24.5%) LEF- and 22 (39.3%) placebo-treated patients. Serious adverse events were reported in six LEF- and four placebo-treated patients. One death was reported in placebo group.

CONCLUSIONS: Although the primary endpoint was not met, our results still provide evidence supporting LEF as a potential alternative treatment option for TAK.

TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02981979.

PMID:42399917 | DOI:10.1186/s12916-026-05009-1