Category: Statistics

Accid Anal Prev. 2025 Jul 10;220:108147. doi: 10.1016/j.aap.2025.108147. Online ahead of print.

ABSTRACT

Incorporating random parameters (RPs) into generalized linearized models (GLMs) – such as the negative binomial (NB) regression model used to predict crash frequencies – has been shown to improve model fit and better address issues such as unobserved heterogeneity. However, applying models with RPs to make predictions for observations outside the sample used to estimate the model is not straightforward. Recent studies have proposed various methods to incorporate RPs in out-of-sample predictions, but these tend to provide biased estimates or are computationally intensive to apply. This paper applies fundamental statistical theory to leverage properties of the underlying RP distributions incorporated into GLMs to provide more direct and accurate predictions, as well as directly estimate prediction variance for out-of-sample observations. Methods are provided for several common RP distributions – including the normal/Gaussian, lognormal, triangular, uniform, and gamma distributions – combined within log-link GLM framework. Additionally, closed-form equations for elasticities and marginal effects for the random parameters are provided. The proposed methods are tested using crash frequency prediction models developed using data from the Highway Safety Information System (HSIS). The results suggest that the proposed exact method provides more accurate predictions than the computational-intensive simulation-based approximation approaches while also being simple to apply. The method is suitable for the widespread use of RPs in research and in practical applications of GLMs.

PMID:40644756 | DOI:10.1016/j.aap.2025.108147

Explore (NY). 2025 Jun 25;21(4):103201. doi: 10.1016/j.explore.2025.103201. Online ahead of print.

ABSTRACT

The aim of this study was to determine the effect of laughter yoga on hemodialysis patients’ disease acceptance, treatment adherence and comfort levels. This randomized controlled study was conducted with 42 patients (experimental group=21, control group=21) who were treated in the hemodialysis unit. Hemodialysis patients in the experimental group received 12 sessions of laughter yoga for four weeks, three days a week. Data were collected using Patient Information Form, Disease Acceptance Scale, End-Stage Renal Disease Adherence Questionnaire, and Hemodialysis Comfort Scale. A significant difference was found between the disease acceptance scale (t(41) = 4.39, p < 0.001, d = 1.364), end-stage renal failure adaptation scale (t(41) = 2.69, p = 0.010, d = 0.830) and hemodialysis comfort scale (t(41) = 5.58, p = 0.010, d = 1.710) of hemodialysis patients who underwent laughter yoga. In addition for the Disease Acceptance Scale, the SD of the pre-test scores was 7.51. Accordingly, the MCID thresholds were calculated as 3.75 (0.5 SD), 3.11 (1 SEM), and 6.09 (1.96 SEM). For the End-Stage Renal Disease Adherence Questionnaire, the SD was 178.79, and the MCID was calculated as 89.40 (0.5 SD), 63.47 (1 SEM), and 124.39 (1.96 SEM). For the Hemodialysis Comfort Scale, the SD was 6.43, resulting in MCID estimates of 3.21 (0.5 SD), 2.01 (1 SEM), and 3.94 (1.96 SEM). Laughter yoga practiced during hemodialysis increased acceptance of the disease, adherence to treatment, and comfort (p < 0.05). In contrast, no statistically significant difference was found in the control group (p > 0.05). Increasing hemodialysis patients’ acceptance of the disease, adherence to treatment, and comfort levels ensure the successful continuation of the disease management process. The practice of laughter yoga in clinics during hemodialysis sessions is recommended to increase disease acceptance, adherence to treatment and comfort levels.

PMID:40644747 | DOI:10.1016/j.explore.2025.103201

Semin Arthritis Rheum. 2025 Jun 27;74:152777. doi: 10.1016/j.semarthrit.2025.152777. Online ahead of print.

ABSTRACT

OBJECTIVE: To test the discriminating capacity of different thresholds of the Assessment of SpondyloArthritis international Society Health Index (ASAS HI) in placebo-controlled trials of patients with axial spondyloarthritis (axSpA), including radiographic (r-axSpA) and non-radiographic (nr-axSpA) subtypes.

METHODS: The discriminating capacities of absolute (≥2.0-≥4.0 points) and relative (≥20%-≥50%) ASAS HI improvement thresholds were evaluated in patients with axSpA from three COAST trials (COAST-V, COAST-W, and COAST-X) of ixekizumab every 4 weeks (IXE Q4W) vs. placebo. Threshold-based response rates at Week 16 were compared between trial arms using Fisher’s exact test. Odds ratios and phi coefficients were used to evaluate how strongly each improvement threshold was associated with treatment allocation in a given trial. Missing data were handled using non-responder imputation.

RESULTS: ASAS HI data were available at baseline and Week 16 for 587 patients in IXE Q4W and placebo arms. The ASAS HI ≥30% improvement threshold effectively discriminated treatment allocation in all trials; significant differences were observed between IXE Q4W and placebo in r-axSpA (COAST-V: p = 0.026; COAST-W: p = 0.023) and nr-axSpA (COAST-X: p = 0.040). Lower absolute (≥2.0-≥3.0 points) and relative (≥20%-≥30%) thresholds discriminated effectively in COAST-W, whereas higher absolute (≥3.5-≥4.0 points) and relative (≥30%-≥50%) thresholds discriminated effectively in COAST-V. In COAST-X, ≥30%, ≥40%, and ≥50% thresholds discriminated effectively. Phi coefficients were small (<0.3) across all trials and thresholds.

CONCLUSIONS: Several ASAS HI improvement thresholds discriminated axSpA patients in treatment vs. placebo arms at Week 16. The ASAS HI ≥30% improvement threshold discriminated across all three COAST trials.

PMID:40644736 | DOI:10.1016/j.semarthrit.2025.152777

J Neurosurg. 2025 Jul 11:1-12. doi: 10.3171/2025.3.JNS241757. Online ahead of print.

ABSTRACT

OBJECTIVE: The Neurosurgery Research & Education Foundation (NREF) Medical Student Summer Research Fellowship (MSSRF) is a prominent research fellowship offered to medical students. The authors investigated how gender and academic characteristics of the MSSRF applicant pool have evolved since the fellowship’s inception. Likewise, they evaluated the impact of the MSSRF on career progression, scholarly productivity, and subsequent grant funding within neurosurgery.

METHODS: A list of MSSRF awardees (2008-2023) and nonawardee applicants (2015-2023) was provided by the NREF. Demographic and career progression variables were obtained through publicly available platforms, and scholarly productivity metrics were collected using Clarivate Web of Science. The Fisher’s exact test was used to compare categorical variables, the Mann-Whitney U-test was used to compare continuous variables, and the Mann-Kendall test was used to assess trends. Binary logistic regression was utilized to explore factors associated with matching into neurosurgery.

RESULTS: A total of 297 awardees from 2008 to 2023, 183 awardees from 2015 to 2023, and 355 nonawardees from 2015 to 2023 were included. A greater percentage of awardees attended a top 20 medical school than nonawardees (p = 0.002). There was a statistically significant upward trend in the percentage of female awardees since 2010 (p = 0.01). Between 2015 and 2023, there was no difference in the percentage of awardees who matched into neurosurgery compared to nonawardees (60.5% vs 50.2%, p = 0.07), but awardees matched into better Doximity-ranked neurosurgery residency programs (p = 0.04). While there was no difference in the number of total publications or first author publications before residency between awardees and nonawardees who matched into neurosurgery since 2015, awardees had a higher h-index (5.0 vs 4.0, p = 0.03). Specifically among awardees who pursued neurosurgery since 2008, there was a statistically significant upward trend in the median number of total publications before residency (p < 0.001), first author publications (p = 0.001), and h-index (p = 0.007). Among neurosurgery attending physicians who received MSSRF awards, 64.7% practiced in an academic setting. Across academic neurosurgery attending physicians who received MSSRF awards, the ratio of NREF MSSRF award dollars to subsequent National Institutes of Health (NIH) grant funding dollars was $1:$9.05.

CONCLUSIONS: The NREF MSSRF is associated with high-quality research and strong academic productivity among aspiring medical students, with a high proportion of awardees pursuing neurosurgery and matching into top-ranked residency programs. Likewise, this early-career fellowship has a substantial return on investment in terms of subsequent NIH grant funding.

PMID:40644721 | DOI:10.3171/2025.3.JNS241757

JMIR Med Inform. 2025 Jul 11;13:e68143. doi: 10.2196/68143.

ABSTRACT

BACKGROUND: Electronic health records (EHRs) provide valuable insights to address clinical and epidemiological research concerning HIV, including the disproportionate impact of the COVID-19 pandemic on people living with HIV. To identify this population, most studies using EHR or claims databases start with diagnostic codes, which can result in misclassification without further refinement using drug or laboratory data. Furthermore, given that antiretrovirals now have indications for both HIV and COVID-19 (ie, ritonavir in nirmatrelvir/ritonavir), new phenotyping methods are needed to better capture people living with HIV. Therefore, we created a generalizable and innovative method to robustly identify people living with HIV, preexposure prophylaxis (PrEP) users, postexposure prophylaxis (PEP) users, and people not living with HIV using granular clinical data after the emergence of COVID-19.

OBJECTIVE: The primary aim of this study was to use computational phenotyping in EHR data to identify people living with HIV (cohort 1), PrEP users (cohort 2), PEP users (cohort 3), or “none of the above” (people not living with HIV; cohort 4) and describe COVID-19-related characteristics among these cohorts.

METHODS: We used diagnostic and laboratory measurements and drug concepts in the National Clinical Cohort Collaborative to create a computational phenotype for the 4 cohorts with confidence levels. For robustness, we conducted a randomly sampled, blinded clinician annotation to assess precision. We calculated the distribution of demographics, comorbidities, and COVID-19 variables among the 4 cohorts.

RESULTS: We identified 132,664 people living with HIV with a high level of confidence, 36,088 PrEP users, 4120 PEP users, and 20,639,675 people not living with HIV. Most people living with HIV were identified by a combination of medical conditions, laboratory measurements, and drug exposures (74,809/132,664, 56.4%), followed by laboratory measurements and drug exposures (15,241/132,664, 11.5%) and then by medical conditions and drug exposures (14,595/132,664, 11%). A higher proportion of people living with HIV experienced COVID-19-related hospitalization (4650,132,664, 3.5%) or mortality (828/132,664, 0.6%) and all-cause mortality (2083/132,664, 1.6%) compared to other cohorts.

CONCLUSIONS: Using an extensive phenotyping algorithm leveraging granular data in an EHR repository, we have identified people living with HIV, people not living with HIV, PrEP users, and PEP users. Our findings offer transferable lessons to optimize future EHR phenotyping for these cohorts.

PMID:40644699 | DOI:10.2196/68143

J Strength Cond Res. 2025 Jul 9. doi: 10.1519/JSC.0000000000005177. Online ahead of print.

ABSTRACT

Kumar, NTA, Oliver, JL, Pedley, JS, Dobbs, IJ, Wong, MA, Lloyd, RS, and Radnor, JM. Maturity-related adaptations to combined strength and plyometric training in pre- and postpeak height velocity boys. J Strength Cond Res XX(X): 000-000, 2025-This study examined the effects of a 12-week training intervention on drop jump kinetics in pre- and post-peak height velocity (PHV) boys. Forty boys from a range of sports, aged 9-17 years, were categorized into two maturity groups (pre- and post-PHV) and subdivided to an experimental (EXP) or control (CON) group. The EXP groups completed twice weekly combined traditional resistance and plyometric training program, whereas the CON groups continued regular sports activities. Drop jump ability was quantified by examining performance variables (jump height, ground contact time, and reactive strength index [RSI]), absolute and relative kinetic variables (force, impulse, and power), and movement strategy variables (spring-like correlation, peak center of mass [COM] displacement, and COM velocity). Differences in all variables were analyzed using 2 × 2 × 2 (maturity × group × time) mixed-model ANOVA. Statistical significance was determined as p < 0.05. There were significant maturity × group × time interactions observed for jump height, RSI, mean and peak breaking force, relative breaking force, net impulse, and for all absolute and relative power variables. The results indicate that maturity status influences responsiveness to combined training in boys, with the post-PHV group showing greater adaptations in drop jump performance than their less mature peers. Practitioners aiming to develop stretch-shortening cycle function in post-PHV youth should program a combination of resistance training and plyometrics. Longer interventions with more focused exposure to plyometric training might be required to elicit more meaningful improvements in drop jump performance in pre-PHV children.

PMID:40644677 | DOI:10.1519/JSC.0000000000005177

J Strength Cond Res. 2025 Jul 9. doi: 10.1519/JSC.0000000000005196. Online ahead of print.

ABSTRACT

Rogers, B, Murias, JM, and Fleitas-Paniagua, PR. Prediction of the maximal metabolic steady state from heart rate variability using a submaximal incremental ramp test. J Strength Cond Res XX(X): 000-000, 2025-Recent studies have demonstrated that the metabolic rate at the heavy-severe exercise intensity boundary can be determined by identifying the respiratory compensation point (RCP) and the second heart rate variability threshold (HRVT2) from incremental ramp testing. This study examined whether the HRVT2 could be extrapolated from submaximal portions of the incremental test. Fifteen subjects (5 men, 10 women, age 23 ± 4 years, V̇o2max 42.6 ± 8.0 ml·kg-1·min-1) underwent incremental cycling ramp testing measuring gas exchange variables along with an open-source application recording detrended fluctuation analysis (DFA a1) and RR intervals. RR data from ramp start to the point at which DFA a1 reached 0.75 were used for HRVT2 extrapolation. Comparisons were made between the V̇o2 and HR at the RCP and HRVT2. Mean values for RCP vs. HRVT2 V̇o2 and HR were not statistically different, 39.0 ± 9.7 vs. 38.8 ± 11.1 ml·kg-1·min-1 and 168 ± 9 vs. 168 ± 12 bpm, respectively, with equivalence verified. Pearson’s r correlation coefficients were 0.92 and 0.60 for RCP vs. HRVT2 V̇o2 and HR, respectively. Bland-Altman analysis showed negligible bias of 0.2 ml·kg-1·min-1 (LOA ±9.0) for V̇o2 and +1 bpm (LOA ±20 bpm) for HR. DFA a1 at the RR interval testing limit was 0.72 ± 0.04 with an HR of 163 ± 12. In this group of healthy recreationally active subjects, the HRVT2 V̇o2 and HR extrapolated from submaximal portions of the incremental test maintained similar agreement and equivalence to the V̇o2 and HR at the RCP as seen in prior studies using testing to exhaustion.

PMID:40644665 | DOI:10.1519/JSC.0000000000005196

JCO Clin Cancer Inform. 2025 Jul;9:e2500111. doi: 10.1200/CCI-25-00111. Epub 2025 Jul 11.

ABSTRACT

PURPOSE: Consumer wearable devices provide new opportunities for measuring patterns of objective daily physical activity throughout cancer treatment. In addition to capturing step counts, these devices can also measure gait cadence and activity fragmentation, two metrics that may reflect functional capacity. The goal of the current study was to examine whether step count, gait cadence, and activity fragmentation predicted overall survival in patients with solid tumors.

METHODS: We enrolled patients (N = 213) receiving outpatient chemotherapy for any solid tumor into an observational cohort study. Patients wore a consumer wearable device to measure continuous physical activity patterns for up to 90 days and were followed for a median of 2.53 years, during which 42% of the sample died. Univariable and multivariable Cox proportional hazards regression analyses were used to evaluate associations between wearable device physical function metrics and survival.

RESULTS: In univariable analyses, higher step count (hazard ratio (HR), 0.87; P = .007), less activity fragmentation (HR, 1.03; P < .001), and faster peak gait cadence (HR, 0.81; P < .001) were significantly associated with lower mortality risk. Associations with activity fragmentation and gait cadence persisted after adjustment for age and cancer type and stage and after additional adjustment for clinician-rated performance status and patient-reported physical function.

CONCLUSION: Activity fragmentation and gait cadence metrics derived from consumer wearable devices were associated with overall survival in patients receiving chemotherapy for any solid tumor. These associations remained statistically significant after adjustment for covariates, including clinician-rated performance status and patient-reported physical function. These findings suggest that wearable devices may capture important prognostic information about physical function independent of what clinicians and patients perceive.

PMID:40644640 | DOI:10.1200/CCI-25-00111

Am J Clin Hypn. 2025 Jul 11:1-17. doi: 10.1080/00029157.2025.2517170. Online ahead of print.

ABSTRACT

Patients with ischemic heart disease exhibit lower subjective well-being. Although hypnosis involving imagery may enhance their well-being, its implementation remains inadequately investigated. Therefore, this feasibility study assessed the feasibility and acceptability of an online hypnotic guided imagery intervention for improving subjective well-being and the occurrence of adverse events in these patients. Ten sex-matched participants were randomly assigned to an experimental group receiving three hypnotic sessions or a control group getting two non-hypnotic sessions, followed by a delayed hypnosis intervention after the posttest. Hypnotic sessions encompassed induction, guided imagery problem-solving, and reinforcement of positive change. The feasibility, acceptability, and potential effects on subjective well-being were evaluated through qualitative feedback and descriptive statistics. The results revealed that online hypnosis was feasible, with the therapist successfully delivering online hypnosis without issues and participants experiencing relaxation, emotional release, and better sleep. The descriptive statistics showed that the experimental group demonstrated greater enhancement in subjective well-being than the control group. While two subjects reported mild dizziness, no serious adverse events were reported. The findings suggest that online hypnosis may be a promising intervention for promoting subjective well-being in ischemic heart disease patients. However, these discoveries require confirmation with larger samples and evaluation of unfavorable effects.

PMID:40644637 | DOI:10.1080/00029157.2025.2517170

JMIR Mhealth Uhealth. 2025 Jul 11;13:e70219. doi: 10.2196/70219.

ABSTRACT

BACKGROUND: Mobile health (mHealth) interventions are increasingly used to reduce risk and promote health in real-time, real-life contexts. Engagement is critical for effectiveness of mHealth interventions but may be challenging for young people experiencing depressive symptoms.

OBJECTIVE: We examined engagement with the 4-week mHealth component of a counseling-plus-mHealth intervention to reduce sexual and reproductive health (SRH) risk among young people with depression (Momentary Affect Regulation – Safer Sex Intervention [MARSSI]) to determine (1) mHealth engagement patterns over time and (2) how sociodemographic characteristics, SRH risks, and depressive symptom severity were associated with these engagement patterns.

METHODS: We undertook secondary analysis of data collected from June 2021 to September 2023 in a randomized controlled trial of MARSSI versus a breast health podcast. Eligibility included age 16-21 years, ability to become pregnant, smartphone ownership, English fluency, past-3-month penile-vaginal sex ≥1x/week and ≥1 SRH risk, and Patient Health Questionnaire-8 item score ≥8. Intervention participants received one-on-one telehealth counseling and then used an app for 4 weeks, responding to surveys (3 prompted at quasi-random, 1 scheduled daily) about affect, effective contraception and condom use self-efficacy, sexual and pregnancy desire, and recent sex, and receiving tailored messages reinforcing the counseling. We computed mHealth engagement days (responding to ≥1 app survey) by week and overall. Latent trajectory analysis identified engagement patterns over the 4 mHealth weeks among participants with any engagement. Using regression analysis, we examined the associations of sociodemographic characteristics, SRH risks, and depressive symptom severity with mHealth engagement patterns and examined moderation by depressive symptom severity. Of the 201 intervention participants, 194 (96.5%) enrolled in the app.

RESULTS: Among those responding to app surveys (167/194, 86.1%), the median engagement was 14 (IQR 4-23) days; 32.9% (55/167) responded on ≥20 days. Overall app engagement (median) declined from 5 (IQR 3-7) days in week 1 to 1 (IQR 0-5) day in week 4. On latent trajectory analysis, 4 patterns of app engagement emerged: high-throughout (48/167, 28.7%), high-then-declining (40/167, 23.9%), mid-then-declining (47/167, 28.1%), and low-throughout (33/167, 19.7%). Participants identifying gender other than female and those perceiving higher socioeconomic status were more likely to have high-throughout or high-then-declining engagement. Asian or Black non-Hispanic participants and those using low-effectiveness contraception were more likely to have no engagement. In the multivariable model, Asian (adjusted odds ratio [AOR] 0.28, 95% CI 0.10-0.81), Black non-Hispanic (AOR 0.28, 95% CI 0.12-0.66), and higher perceived socioeconomic status (AOR 1.24, 95% CI 1.05-1.48) remained significantly associated with engagement. Engagement patterns showed no differences by depressive symptom severity and no significant moderation.

CONCLUSIONS: Young people with depressive symptoms showed initial high engagement with the intervention’s mHealth app to reduce adverse SRH outcomes. Methods to increase and sustain mHealth engagement and differences in engagement by sociodemographic characteristics warrant further studies to optimize the reach of mHealth interventions.

PMID:40644628 | DOI:10.2196/70219