02.02.01. Investigación y comunicación científica

Construct Validity of Frontier Large Language Models on 4 Spanish Health Professions Specialty-Access Examinations (MIR, EIR, PIR, and FIR): Cross-Sectional Benchmarking and Psychometric Study.

2026-10-29T00:00:00Z

Construct Validity of Frontier Large Language Models on 4 Spanish Health Professions Specialty-Access Examinations (MIR, EIR, PIR, and FIR): Cross-Sectional Benchmarking and Psychometric Study. García-Hidalgo, Clemente; Carpio-Salmerón, Manuel; Benito, Pau; Carazo-Casas, Carlos; Carratala, Beatriz; Campos-Pavon, Jaime BACKGROUND: Large language models (LLMs) achieve high scores on health-professions examinations. Whether these scores support the same interpretations as human scores remains uncertain. Spain uses parallel multiple-choice examinations for entry to specialty training in medicine (Médico Interno Residente [MIR]), nursing (Enfermero Interno Residente [EIR]), psychology (Psicólogo Interno Residente [PIR]), and pharmacy (Farmacéutico Interno Residente [FIR]). OBJECTIVE: Using the January 2026 MIR, EIR, PIR, and FIR examinations, this study aimed to quantify the correspondence between human and LLM item facility and to describe model accuracy, distractor selection, and performance associated with measured surface features. METHODS: We evaluated 839 valid items using 12 configurations: GPT-5.2 at 3 reasoning efforts and Claude Opus, Sonnet, and Haiku 4.5 (Anthropic), each under neutral and expert prompts, with one run per configuration. The primary measure was the Spearman correlation (?) between human and machine facility on 828 complete paired items. We examined sensitivity to panel composition, scoring, pooling, and assumed reliability; compared distractor choices with a post hoc plausibility-weighted baseline; and evaluated a surface-feature classifier. Image analyses distinguished supplied from withheld images. An exploratory LLM-judge audit assessed generated explanations. Bootstrap CIs resample items or, for distractor concordance, error events; they exclude run-to-run uncertainty. RESULTS: The highest pooled accuracy was 94.8% (795/839); all 12 configurations answered 668 of 828 paired items correctly (80.7%). Scores clustered near the ceiling among the strongest configurations. Human and machine facility correlated at 0.40 (95% CI 0.34-0.45), with estimates of 0.31 to 0.40 across panel definitions and 0.39 (95% CI 0.33-0.45) after exam-stratified pooling. The observed correlation was lower than predicted by a specified one-axis simulation with a uniform model advantage (0.63; predictive interval 0.59 to 0.66; P<.001). Among 672 model errors, dominant human-distractor selection differed from the plausibility-weighted baseline by -1.25 percentage points (95% CI -4.53 to 2.19), compatible with no difference. Surface-feature accuracy was 34.4% (289/839), similar to selecting the longest option (34.6%, 290/839). The adjusted association with model correctness was uncertain (odds ratio [OR] 0.87, 95% CI 0.72-1.04). Image-associated accuracy was lower both when images were supplied (OR 0.33, 95% CI 0.21-0.53) and when withheld (OR 0.11, 95% CI 0.08-0.16). CONCLUSIONS: In this single 2026 cohort, high LLM scores coexisted with limited separation among the strongest configurations and moderate correspondence with human item difficulty. These findings caution against interpreting model scores as equivalent evidence of human competence. They do not establish clinical performance or invalidate the examinations for human candidates.

Correlation Between Ultrasound-Derived Diaphragmatic Thickness, Inspiratory Muscle Strength and Peak Expiratory Flow in Institutionalized Older Adults: A Cross-Sectional Exploratory Study

2026-10-21T00:00:00Z

Correlation Between Ultrasound-Derived Diaphragmatic Thickness, Inspiratory Muscle Strength and Peak Expiratory Flow in Institutionalized Older Adults: A Cross-Sectional Exploratory Study de-Oliveira-Sousa, Silvana-Loana; Portillo-Castano, Felipe-J; Fernández-Azorin, Luis; Leon-Morillas, Felipe; Ríos-Cortés, Antonio-Tomás; Oliveira, Adriana-C-de-Souza Background: Diaphragm thickness may affect both inspiratory and expiratory function. The ultrasound assessment of diaphragm thickness could be a valuable tool for respiratory muscle evaluation in older adults, although additional research is needed to clarify its association with respiratory functional parameters. Objectives: The primary objective was to explore the relationship between diaphragm thickness (DT), maximal inspiratory pressure (MIP), and peak expiratory flow (PEF) in institutionalized older adults. A secondary objective was to compare MIP and PEF values between participants with normal and thin diaphragm thickness. Methods: A cross-sectional exploratory study was conducted among older adults (n = 36) residing in long-term care facilities (LTCFs) in Spain. DT was measured at the end of maximum inspiration (DTi) and at the end of expiration at rest (DTe) in the supine position. The diaphragm thickening difference (DTD) and diaphragm fraction (DTF) were calculated. A thin diaphragm was defined as a diaphragm thickness (DTe) <1.6 mm in men and <1.4 mm in women. The maximum inspiratory pressure (MIP) was measured using a Powerbreath KH1 device, and the peak expiratory flow (PEF) was measured using Datospir Peak-10. Spearman's rank correlation coefficient and linear regression models were used to explore the association between diaphragm thickness and respiratory muscle function. Statistical analysis was performed using IBM SPSS Statistics 22.0. Results: The mean age of the participants was 82.4 ± 7.9 years (24 females-12 males). Significant correlations were observed among most ultrasound-derived measures. DTi was positively associated with MIP (? = 0.403, 95% CI 0.065-0.658; q = 0.033) and PEF (? = 0.534, 95% CI 0.235-0.741; q = 0.003), DTe with MIP (? = 0.445, 95% CI 0.116-0.686; q = 0.020), and DTD with PEF (? = 0.475, 95% CI 0.158-0.703; q = 0.012). Compared with participants with normal diaphragm thickness, those with a thin diaphragm exhibited lower MIP (? = ?18.43, 95% CI: ?32.76 to ?4.18; p = 0.013). Conclusions: Diaphragm thickness was positively associated with inspiratory muscle strength and peak expiratory flow. Participants with a thin diaphragm demonstrated lower respiratory muscle performance than those with normal diaphragm thickness. However, these findings should be interpreted with caution, and additional studies are needed to confirm these associations.

Short-Term Methylcobalamin Supplementation Is Associated with Changes in Anaerobic and Cognitive Performance in Amateur Cyclists: A Randomized Crossover Trial

2026-05-23T00:00:00Z

Short-Term Methylcobalamin Supplementation Is Associated with Changes in Anaerobic and Cognitive Performance in Amateur Cyclists: A Randomized Crossover Trial Martínez-Noguera, Francisco-Javier; Alcaraz, Pedro-E; González-Blanc, Francisco-Jesús; Huyghe, Thomas-G; Marín-Pagán, Cristian Introduction: Vitamin B12 (VB12), particularly its active form methylcobalamin (MeB12), contributes to neuromuscular function and energy metabolism, which may be relevant for sports performance. However, evidence on the acute effects of MeB12 supplementation in athletes remains limited. Objective: To evaluate the effects of short-term (3-day) MeB12 supplementation on anaerobic and cognitive performance in amateur cyclists. Methods: A randomized, triple-blind, placebo-controlled crossover clinical trial was conducted in 18 amateur cyclists. Participants received formulations containing MeB12 (1 mg/day; MecobalActive®, HTBA, Murcia, Spain) or placebo for three consecutive days. Anaerobic performance was assessed using a repeated Wingate protocol, and cognitive performance was evaluated using a light-based mental agility/reaction test system. Biochemical analyses included serum VB12 concentrations. Primary outcomes included peak power output (absolute and relative), fatigue index across repeated sprints, and cognitive response time. Results: Compared with placebo, MeB12 supplementation was associated with higher peak power output, with increases in absolute maximal power (PMAX: +4.1%, p = 0.016) and relative maximal power (PMAXREL: +4.4%, p = 0.013). MeB12 supplementation was associated with a smaller decline in performance across repeated sprints, with a smaller drop in fatigue index from the first to the fifth sprint (p = 0.012). Pre-exercise cognitive performance improved, with a shorter total reaction test time (?4.9%, p < 0.001) versus placebo. Serum VB12 concentrations increased by 16.8% following MeB12 supplementation. Conclusions: A brief, 3-day intervention with methylcobalamin (1 mg/day) was associated with positive changes, when compared with placebo, in selected markers of anaerobic performance (peak power and fatigue-related decline) and pre-exercise cognitive performance in recreationally trained amateur cyclists, suggesting a possible involvement of peripheral and central mechanisms.

Non-technique-related healthcare utilization and costs among dialysis and kidney transplant recipients in Spain: a real-world analysis

2026-07-22T00:00:00Z

Non-technique-related healthcare utilization and costs among dialysis and kidney transplant recipients in Spain: a real-world analysis Santamaria, Rafael; Escobar, Carlos; Aranda, Unai; Palacios, Beatriz; Capel, Margarita; Hernández, Ignacio; Cebrián-Cuenca, Ana-María; Gorostidi, Manuel; Alcazar, Roberto BACKGROUND: Kidney failure requiring kidney replacement therapy (KRT) is associated with a substantial and growing economic burden. While the costs directly attributable to KRT modalities are well documented, the resource use and costs unrelated to KRT modalities remain unclear. OBJECTIVE: To quantify healthcare resource utilization (HCRU) and costs in patients receiving dialysis or kidney transplantation, excluding technique-related costs. METHODS: This retrospective observational study used BIG-PAC real-world data to analyze dialysis or kidney transplant patients as of January 1, 2018, with a two-year follow-up. Patients were identified based on related diagnostic or procedure codes recorded in electronic health records (EHRs) prior to the index date. Major adverse cardiovascular events (MACE), hospitalization for CKD and mortality were evaluated. HCRU, direct healthcare costs, and indirect productivity costs due to sick leave were assessed, excluding technique-related KRT costs. RESULTS: Of 70,973 individuals, 356 (0.5%) were on dialysis and 232 (0.3%) had kidney transplantation. Over two years, MACE per 1000 patient-years were 276.3 for dialysis and 85.9 for transplantation. CKD hospitalization rates were 245.7 and 183.0, with mortality rates of 253.8 and 35.6, respectively. First-year health costs averaged ?25,410.4 (SD ?17,369.0) for dialysis patients and ?4,472.8 (SD ?2,859.1) for transplant recipients. Most costs among dialysis and kidney transplant patients were driven by hospitalization, 72.4% and 39.8%, respectively. Indirect costs due to sick leave were also substantial. CONCLUSION: Non-technique-related costs represent a substantial component of the overall economic burden in patients receiving KRT, largely driven by hospitalizations. These findings provide important context for healthcare planning, although they do not represent total costs of care and should be interpreted as descriptive estimates.