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Nevin Manimala Statistics

Improved efficiency for cross-arm comparisons via platform designs

Biostatistics. 2022 Aug 8:kxac030. doi: 10.1093/biostatistics/kxac030. Online ahead of print.

ABSTRACT

Though platform trials have been touted for their flexibility and streamlined use of trial resources, their statistical efficiency is not well understood. We fill this gap by establishing their greater efficiency for comparing the relative efficacy of multiple interventions over using several separate, 2-arm trials, where the relative efficacy of an arbitrary pair of interventions is evaluated by contrasting their relative risks as compared to control. In theoretical and numerical studies, we demonstrate that the inference of such a contrast using data from a platform trial enjoys identical or better precision than using data from separate trials, even when the former enrolls substantially fewer participants. This benefit is attributed to the sharing of controls among interventions under contemporaneous randomization. We further provide a novel procedure for establishing the noninferiority of a given intervention relative to the most efficacious of the other interventions under evaluation, where this procedure is adaptive in the sense that it need not be a priori known which of these other interventions is most efficacious. Our numerical studies show that this testing procedure can attain substantially better power when the data arise from a platform trial rather than multiple separate trials. Our results are illustrated using data from two monoclonal antibody trials for the prevention of HIV.

PMID:35939566 | DOI:10.1093/biostatistics/kxac030

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Nevin Manimala Statistics

CoCoA: conditional correlation models with association size

Biostatistics. 2022 Aug 8:kxac032. doi: 10.1093/biostatistics/kxac032. Online ahead of print.

ABSTRACT

Many scientific questions can be formulated as hypotheses about conditional correlations. For instance, in tests of cognitive and physical performance, the trade-off between speed and accuracy motivates study of the two variables together. A natural question is whether speed-accuracy coupling depends on other variables, such as sustained attention. Classical regression techniques, which posit models in terms of covariates and outcomes, are insufficient to investigate the effect of a third variable on the symmetric relationship between speed and accuracy. In response, we propose a conditional correlation model with association size, a likelihood-based statistical framework to estimate the conditional correlation between speed and accuracy as a function of additional variables. We propose novel measures of the association size, which are analogous to effect sizes on the correlation scale while adjusting for confound variables. In simulation studies, we compare likelihood-based estimators of conditional correlation to semiparametric estimators adapted from genomic studies and find that the former achieves lower bias and variance under both ideal settings and model assumption misspecification. Using neurocognitive data from the Philadelphia Neurodevelopmental Cohort, we demonstrate that greater sustained attention is associated with stronger speed-accuracy coupling in a complex reasoning task while controlling for age. By highlighting conditional correlations as the outcome of interest, our model provides complementary insights to traditional regression modeling and partitioned correlation analyses.

PMID:35939558 | DOI:10.1093/biostatistics/kxac032

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Nevin Manimala Statistics

Efficacy and safety of PD-1/PD-L1 inhibitors in triple-negative breast cancer: a systematic review and meta-analysis

Acta Oncol. 2022 Aug 8:1-11. doi: 10.1080/0284186X.2022.2106795. Online ahead of print.

ABSTRACT

OBJECTIVE: Triple-negative breast cancer (TNBC) is a subtype of breast cancer with a poor prognosis that seriously threatens women’s health. There is still a lack of effective therapeutic targets for TNBC treatment. We conducted a meta-analysis to evaluate the efficacy and safety of programmed cell death protein 1 (PD-1)/programmed death protein ligand 1 (PD-L1) inhibitors in combination with chemotherapy for TNBC patients.

METHODS: We searched PubMed, EMBASE, Cochrane Library, and Web of Science for randomized controlled trials (RCTs) related to PD-1/PD-L1 inhibitors combined with chemotherapy. Literature conforming to the research content was identified according to the inclusion and exclusion criteria. The endpoints of efficacy were pathological complete response (pCR), event-free survival (EFS), progression-free survival (PFS), and overall survival (OS). Safety outcomes included adverse events (AEs) of any grade, AEs of grade ≥3, serious AEs, and the incidence of various AEs. We obtained odds ratios (OR), hazard ratio (HR), and 95% confidence interval (CI) for the included studies. Data analysis was performed using Review Manager software (version 5.3).

RESULTS: A total of 4468 patients from eight RCTs were analyzed. PD-1/PD-L1 inhibitors in combination with chemotherapy significantly improved pCR (OR, 1.59; 95% CI, 1.28 – 1.98, p < 0.0001), EFS (HR, 0.66; 95% CI, 0.48 – 0.91, p = 0.01), and OS (HR, 0.72; 95% CI, 0.52 – 0.99, p = 0.05) in patients with TNBC compared to chemotherapy alone or placebo in combination with chemotherapy. Furthermore, we found that the pCR rate was almost identical in the PD-L1 positive group (OR, 1.65; 95% CI, 1.26 – 2.16, p = 0.0002) and the PD-L1 negative group (OR, 1.56; 95% CI, 1.04 – 2.33, p = 0.03). Among patients with advanced-stage TNBC, PFS (HR, 0.82; 95% CI, 0.74 – 0.90, p < 0.0001) was longer in the combination therapy group than in the chemotherapy group. There were no statistically significant differences between the experimental and control groups in OS (HR, 1.03; 95% CI, 0.74 – 1.42, p = 0.87). In terms of safety, we found that the combination therapy group had a significantly higher incidence of hyperthyroidism in patients with early and advanced TNBC (OR, 5.76; 95% CI, 2.38 – 13.95, p = 0.0001) (OR, 7.86; 95% CI, 2.65 – 23.29, p = 0.0002).

CONCLUSIONS: The combination of PD-1/PD-L1 inhibitors and chemotherapy could improve the survival and prognosis of patients with early and advanced TNBC. Combination treatment may be harmful to the thyroid; therefore, active surveillance and regular follow-up are necessary during treatment.

PMID:35939538 | DOI:10.1080/0284186X.2022.2106795

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Nevin Manimala Statistics

Statistical Properties of Bit Strings Sampled from Sycamore Random Quantum Circuits

J Phys Chem Lett. 2022 Aug 8:7469-7475. doi: 10.1021/acs.jpclett.2c02045. Online ahead of print.

ABSTRACT

Quantum supremacy has been recently reported for random circuit sampling on the Sycamore processor with 53 qubits. Here, we analyze the statistical properties of bit strings sampled from random quantum circuits. In contrast to classical random bit strings, bit strings sampled from Sycamore random circuits give rise to heat maps with stripe patterns at specific qubits, have more bit 1 than 0, and do not pass the NIST random number tests. The difference between the Sycamore bit strings and classical random bit strings is also demonstrated by the Marchenko-Pastur distribution and the Girko circular law of random matrices. The calculation of Wasserstein distances shows that the Sycamore bit strings are farther from bit strings sampled from Haar-measure random quantum circuits than classical random bit strings. Our results show that random matrices and Wasserstein distances could be used to analyze the performance of quantum computers.

PMID:35939529 | DOI:10.1021/acs.jpclett.2c02045

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Nevin Manimala Statistics

Surgeon Preference on Sending Routine Tonsillectomy Specimens for Pathological Evaluation

Ear Nose Throat J. 2022 Aug 8:1455613221112761. doi: 10.1177/01455613221112761. Online ahead of print.

ABSTRACT

INTRODUCTION: Despite the presence of a growing body of literature suggesting cost-ineffectiveness of routine pathologic analysis of tonsillectomy specimens, little is known about common institutional policies and practice patterns of pediatric otolaryngologists. The objectives of this study were to determine the prevalence of routine pathological evaluation of tonsillectomy specimens for uncomplicated pediatric adenotonsillectomy procedures and to evaluate opinions regarding this controversy among board-certified pediatric otolaryngologists.

METHODS: This was a cross-sectional survey study sent to board-certified pediatric otolaryngologists currently practicing and registered with the American Society of Pediatric Otolaryngology (ASPO) assessing their institutions’ or practices’ current policies on sending routine tonsillectomy specimens for pathology, their experience with this practice, and their opinions on whether routine pathologic analysis should be employed. Basic statistical analysis was then conducted.

RESULTS: Respondents mostly practiced in an academic setting (68.4%), with the next most common being academically affiliated private practice (21.8%), and private practice was the least common (9.8%). Most respondents (85.1%) did not agree with routine pathologic analysis of otherwise uncomplicated pediatric tonsillectomy specimens.

CONCLUSION: Most pediatric otolaryngologists who responded to this survey do not support routine pathological analysis of otherwise uncomplicated pediatric tonsillectomy specimens. However, the results are likely biased and should be interpreted carefully, since only a small percentage of pediatric otolaryngologists responded to the survey. Potential cost savings could be seen by patients, payers, and hospital systems with judicious use of surgical pathology, specifically in cases with concurrent signs or symptoms suspicious for malignancy.

PMID:35939505 | DOI:10.1177/01455613221112761

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Nevin Manimala Statistics

‘Poppers Maculopathy’ and the adverse ophthalmic outcomes from the recreational use of alkyl nitrate inhalants: a systematic review

Semin Ophthalmol. 2022 Aug 7:1-9. doi: 10.1080/08820538.2022.2108717. Online ahead of print.

ABSTRACT

OBJECTIVE: The aim of this systematic review and meta-analysis was to provide an overview of reported cases of poppers maculopathy and a statistical analysis of the clinical presentations, anatomical changes and treatment and follow-up of the rare disease.

METHODS: A systematic search of CINAHL, Embase and PubMed databases was conducted, including a search of the grey literature. Data were pooled to provide a summary of the clinical characteristics and outcomes of poppers maculopathy. Studies were critically appraised using the Joanna Briggs Institute or the Authority, Accuracy, Coverage, Objectivity, Date, Significance checklists.

RESULTS: Of the 493 articles obtained, 32 were included, consisting of 113 participants with a mean age of 40.2. Most patients were male with bilateral maculopathy and presented with either vision loss or a visual disturbance. Cessation of popper use was the most common form of management prescribed. The mean VA at baseline was 0.22 (logMAR units). For those followed-up, the mean VA significantly improved from 0.24 to 0.11 (Z = -5.800, p = <0.001). Bilateral yellow foveal spots were viewed on fundoscopy in 53 patients, and a sub-foveal disturbance of the ellipsoid layer was reported on spectral domain optical coherence tomography in 89 patients. By 6 months, SD-OCT anatomical changes mostly improved or resolved.

CONCLUSION: Recreational users of poppers who develop maculopathy generally present with vision loss or a visual disturbance secondary to foveal disruption. Patients have a good visual prognosis, with cessation of poppers potentially having a role in improved outcomes. With the high prevalence of use among gay and bisexual men, awareness of related maculopathy and presenting symptoms by clinicians is important to mitigate side effects.

PMID:35938499 | DOI:10.1080/08820538.2022.2108717

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Nevin Manimala Statistics

Improvement in Clinical Outcomes and Access to Care With Pharmacist-Led Chronic Care Management Services at a Rural Family Medicine Clinic

J Pharm Pract. 2022 Aug 7:8971900221118232. doi: 10.1177/08971900221118232. Online ahead of print.

ABSTRACT

BACKGROUND: Chronic care management (CCM) can significantly impact the management of chronic diseases in rural patient populations. To date, few practice models have addressed its impact on clinical outcomes and access to care in rural practice settings.

OBJECTIVE: Implement a sustainable pharmacist-led CCM practice model while tracking clinical outcomes and healthcare access at a rural, medically underserved family medicine clinic.

METHODS: This study retrospectively examined data from the clinic’s CCM program from October 2020 through May 2021 and included total clinical encounters at three- and 6-months intervals, as well as changes in clinical outcomes like A1c and systolic blood pressure (SBP) at three- and 6-months intervals.

RESULTS: Over an 8-month period, 46 patients were enrolled in pharmacist-led CCM services. Those with a CCM encounter or office visit within 3 months of enrollment showed a mean A1c reduction of 1.07% after 3 months (95% CI -1.70 to -.44, P = .0016), while those with an encounter or office visit within 6 months of enrollment displayed a mean A1c reduction of 1.64% after 6 months (95% CI -2.35 to -.92, P < .001). There was a 73.8% increase in total clinical encounters in the 6 months after CCM enrollment compared to the 6 months preceding it, signifying increased access to care.

CONCLUSION: Patients with CCM encounters or office visits within the first 3-6 months experienced statistically significant reductions in A1c. Moreover, total clinical encounters markedly increased in the 6 months after enrollment, allowing for more frequent engagement between ambulatory pharmacists and traditionally challenging rural patients.

PMID:35938485 | DOI:10.1177/08971900221118232

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Nevin Manimala Statistics

Influence of thermal processing on the quality of hawthorn: quality markers of heat-processed hawthorn

J Sep Sci. 2022 Aug 8. doi: 10.1002/jssc.202200222. Online ahead of print.

ABSTRACT

Hawthorn and its derived products are used worldwide as foods as well as complementary medicine. During the preparation of hawthorn, heating and thermal processing are frequently reported. The thermal processing will change the medicinal purposes and modify the efficacy of hawthorn. However, details including the chemical profile shifting and quality markers of heat-processed hawthorn have not been well understood. In the paper, we analyzed the hawthorn samples processed at different temperatures and different times by ultraviolet visible absorption spectrum and LC-MS technologies combined with multivariate statistical analysis. It was revealed for the first time that thermal processing could greatly change the ultraviolet visible absorption spectra and chemical profiles of hawthorn even with heat treatment at 130°C for 10 minutes. And the ultraviolet visible absorption spectrum, especially the ratio value (RA500 nm/400 nm ), was a descriptive and qualitative indicator of heating degree for the thermal processing at the macroscopic level. Several components, such as hyperoside, chlorogenic acid, quercetin and apigenin, decreased or increased in content during the processing, and they could be utilized as the chemical quality markers. The proposed quality markers for heat-processed hawthorn will be helpful for further optimizing the processing conditions of hawthorn. This article is protected by copyright. All rights reserved.

PMID:35938469 | DOI:10.1002/jssc.202200222

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Nevin Manimala Statistics

Charge-transfer plasmons of complex nanoparticle arrays connected by conductive molecular bridges

Phys Chem Chem Phys. 2022 Aug 8. doi: 10.1039/d2cp01811j. Online ahead of print.

ABSTRACT

Charge-transfer plasmons (CTP) in complexes of metal nanoparticles bridged by conductive molecular linkers are theoretically analysed using a statistic approach. The applied model takes into account the kinetic energy of carriers inside the linkers including its dissipation and the Coulomb energy of the charged nanoparticles. The plasmons are statistically investigated for systems containing a large number of complexes of bridged nanoparticles of realistic sizes generated using a simplified molecular dynamics algorithm, where the geometries of the complexes are dependent on the rate of connection of the linkers with the nanoparticles. As illustrated, the distribution of CTP frequencies in the generated nanoparticle complexes is very inhomogeneous. It has a narrow peak, corresponding to CTP plasmons in dimers, and two broad peaks, corresponding mainly to low and high-frequency oscillations in chains of connected nanoparticles. It is found that in general the plasmon frequencies depend inversely on the value of the complex dipole moment of the plasmon oscillation, where the assumption follows that low-frequency plasmons will be more efficiently excited in an external electromagnetic field. To calculate the CTP energy absorption in this field two model modifications are proposed: a system-external electromagnetic field interaction model and a simplified broadening plasmon peak model where the plasmons are calculated at first without damping and where the delta-shaped oscillation peaks are broadened then due to the damping. It is demonstrated that both modifications lead to a wide and almost monotonic absorption in the IR region for all generated systems containing a large number of bridged nanoparticles due to the presence of a large number of CTPs in this region.

PMID:35938445 | DOI:10.1039/d2cp01811j

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Nevin Manimala Statistics

A longitudinal examination of perinatal testosterone, estradiol and vitamin D as predictors of handedness outcomes in childhood and adolescence

Laterality. 2022 Aug 6:1-34. doi: 10.1080/1357650X.2022.2109656. Online ahead of print.

ABSTRACT

The developmental origins of handedness remain elusive, though very early emergence suggests individual differences manifesting in utero could play an important role. Prenatal testosterone and Vitamin D exposure are considered, yet findings and interpretations remain equivocal. We examined n = 767 offspring from a population-based pregnancy cohort (The Raine Study) for whom early biological data and childhood/adolescent handedness data were available. We tested whether 18-week maternal circulatory Vitamin D (25[OH]D), and testosterone and estradiol from umbilical cord blood sampled at birth predicted variance in direction of hand preference (right/left), along with right- and left-hand speed, and the strength and direction of relative hand skill as measured by a finger-tapping task completed at 10 (Y10) and/or 16 (Y16) years. Although higher concentrations of Vitamin D predicted more leftward and less lateralized (regardless of direction) relative hand skill profiles, taken as a whole, statistically significant findings typically did not replicate across time-point (Y10/Y16) or sex (male/female) and were rarely detected across different (bivariate/multivariate) levels of analysis. Considering the number of statistical tests and generally inconsistent findings, our results suggest that perinatal testosterone and estradiol contribute minimally, if at all, to subsequent variance in handedness. Vitamin D, however, may be of interest in future studies.

PMID:35938410 | DOI:10.1080/1357650X.2022.2109656