Tag: statistics

J Transl Med. 2024 Jan 4;22(1):16. doi: 10.1186/s12967-023-04827-8.

ABSTRACT

BACKGROUND: p value is the most common statistic reported in scientific research articles. Choosing the conventional threshold of 0.05 commonly used for the p value in research articles, is unfounded. Many researchers have tried to provide a reasonable threshold for the p value; some proposed a lower threshold, eg, 0.005. However, none of the proposals has gained universal acceptance. Using the analogy between the diagnostic tests with continuous results and statistical inference tests of hypothesis, I wish to present a method to calculate the most appropriate p value significance threshold using the receiver operating characteristic curve (ROC) analysis.

RESULTS: As with diagnostic tests where the most appropriate cut-off values are different depending on the situation, there is no unique cut-off for the p significance threshold. Unlike the previous proposals, which mostly suggest lowering the threshold to a fixed value (eg, from 0.05 to 0.005), the most appropriate p significance threshold proposed here, in most instances, is much less than the conventional cut-off of 0.05 and varies from study to study and from statistical test to test, even within a single study. The proposed method provides the minimum weighted sum of type I and type II errors.

CONCLUSIONS: Given the perplexity involved in using the frequentist statistics in a correct way (dealing with different p significance thresholds, even in a single study), it seems that the p value is no longer a proper statistic to be used in our research; it should be replaced by alternative methods, eg, Bayesian methods.

PMID:38178182 | DOI:10.1186/s12967-023-04827-8

Diabetol Metab Syndr. 2024 Jan 4;16(1):8. doi: 10.1186/s13098-023-01217-4.

ABSTRACT

BACKGROUND: Women at risk of gestational diabetes mellitus (GDM) need preventative interventions.

OBJECTIVE: To evaluate targeted interventions before and during pregnancy for women identified as being at risk of developing GDM.

METHODS: Systematic review and meta-analysis conducted following PRISMA guidelines. MEDLINE, EMBASE and the Cochrane Library in addition to reference and citation lists were searched to identify eligible randomised controlled trials (RCTs) utilising risk stratification during the preconception period or in the first/early second trimester. Screening and data extraction were carried out by the authors independently. Quality assessment was conducted based on the Cochrane risk-of-bias tool. Random effects meta-analysis and narrative synthesis were performed.

RESULTS: Eighty-four RCTs were included: two during preconception and 82 in pregnancy, with a pooled sample of 22,568 women. Interventions were behavioural (n = 54), dietary supplementation (n = 19) and pharmacological (n = 11). Predictive factors for risk assessment varied; only one study utilised a validated prediction model. Gestational diabetes was reduced in diet and physical activity interventions (risk difference – 0.03, 95% CI 0.06, – 0.01; I² 58.69%), inositol (risk difference – 0.19, 95% CI 0.33, – 0.06; I² 92.19%), and vitamin D supplements (risk difference – 0.16, 95% CI 0.25, – 0.06; I² 32.27%). Subgroup analysis showed that diet and physical activity interventions were beneficial in women with ≥ 2 GDM risk factors (risk difference – 0.16, 95% CI 0.25, – 0.07; I² 11.23%) while inositol supplementation was effective in women with overweight or obesity (risk difference – 0.17, 95% CI 0.22, – 0.11; I² 0.01%). Effectiveness of all other interventions were not statistically significant.

CONCLUSIONS: This review provides evidence that interventions targeted at women at risk of GDM may be an effective strategy for prevention. Further studies using validated prediction tools or multiple risk factors to target high-risk women for intervention before and during pregnancy are warranted.

PMID:38178175 | DOI:10.1186/s13098-023-01217-4

Int J Paleopathol. 2024 Jan 3;44:85-89. doi: 10.1016/j.ijpp.2023.12.004. Online ahead of print.

ABSTRACT

OBJECTIVE: X-ray fluorescence (XRF) is a non-destructive technique that measures the elemental concentration of different materials, including human bone. Recently, it began to be applied to paleopathological studies due to the development of portable devices and their relative ease of use. However, the lack of uniform procedures hampers comparability and reproducibility. This paper aims to provide guidelines for an efficient and standardized evaluation of bone elemental composition with a portable XRF (pXRF) device.

MATERIALS: This technical note is based on the application of the Thermo Scientific Niton XL3t 900 GOLDD+.

METHODS: This work includes suggestions for the choice and preparation of human bone samples, both from archaeological context and documented collections, and methodological procedures in pXRF setup, such as choice of calibration, assessment of accuracy, and analysis run time. Additionally, recommendations for data validation and statistical analysis are also included.

CONCLUSIONS: This technique has great potential in paleopathology since bone chemical variations may be associated with different pathological conditions, environmental contamination (e.g., lead), and/or administered treatments, such as mercury. Following an expected increase in the number of studies, it is essential to establish good practices that allow results from different researchers to be comparable.

SIGNIFICANCE: X-ray fluorescence is a non-destructive technique that measures small concentrations (ppm) of elements from magnesium (12Mg) through bismuth (83Bi).

LIMITATIONS: pXRF does not detect elements lighter than Mg, and its lower energy excitation penetrates less than other techniques.

SUGGESTIONS FOR FURTHER RESEARCH: Other research groups should test these guidelines and comment on their usefulness and replicability.

PMID:38176088 | DOI:10.1016/j.ijpp.2023.12.004

Physiol Meas. 2024 Jan 4. doi: 10.1088/1361-6579/ad1b10. Online ahead of print.

ABSTRACT

Smoking is widely recognized as a significant risk factor in the progression of arterial stiffness and cardiovascular diseases. Valuable information related to cardiac arrhythmias and heart function can be obtained by analyzing biosignals such as the electrocardiogram (ECG) and the photoplethysmogram (PPG). The PPG signal is a non-invasive optical technique that can be used to evaluate the changes in blood volume, and thus it can be linked to the health of the vascular system.

OBJECTIVE: In this study, the impact of three smoking habits -cigarettes, shisha, and electronic cigarettes (e-cigarettes)- on the features of the PPG signal were investigated.

APPROACH: The PPG signals are measured for 45 healthy smokers before, during, and after the smoking session and then processed to extract the morphological features. Quantitative statistical techniques were used to analyze the PPG features and provide the most significant features in the three smoking habits. The impact of smoking is observed through significant changes in the features of the PPG signal, indicating blood volume instability.

MAIN RESULTS: The results revealed that the three smoking habits influence the characteristics of the PPG signal significantly, which persist even after 15 minutes of smoking. Among them, shisha has the greatest impact on PPG features, particularly on heart rate, systolic time, augmentation index, and peak pulse interval change. In contrast, e-cigarettes have the least effect on PPG features. Interestingly, smoking electronic cigarettes, which many participants use as a substitute for traditional cigarettes when attempting to quit smoking, has nearly a comparable effect to regular smoking.

SIGNIFICANCE: The findings suggest that individuals who smoke shisha are more likely to develop cardiovascular diseases at an earlier age compared to those who have other smoking habits. Understanding the variations in the PPG signal caused by smoking can aid in the early detection of cardiovascular disorders and provide insight into cardiac conditions. This ultimately contributes to the prevention of the development of cardiovascular diseases and the development of a health screening system.

PMID:38176078 | DOI:10.1088/1361-6579/ad1b10

Aerosp Med Hum Perform. 2023 Dec 1;94(12):939-943. doi: 10.3357/AMHP.6342.2023.

ABSTRACT

INTRODUCTION: Management of aeromedical risk is essential for flight safety. Given the many operator stressors for pilots, militaries maintain a vested interest in selecting aircrew applicants who meet rigorous initial medical standards. Very little published literature exists regarding the extent of medical disqualifications or precluding conditions for initial candidates.METHODS: For the British Army, pilot selection is a phased, multistep process that includes Phase I medical screening followed by a comprehensive Phase II medical exam. De-identified summary data were retrospectively reviewed for medical fitness and disqualifying categories for the 5-yr period of 2018-2022, inclusive. For those ultimately deemed unfit for aviation service, etiology was grouped into general categories.RESULTS: Approximately one-third (30.2%) of candidates were disqualified at Phase I initial medical screening with leading categories of attrition due to respiratory etiology, especially a history of asthma or reactive airway disease, followed by ophthalmology. For the Phase II medical exam cohort, 21.0% were medically disqualified with most attrition from anthropometry and ophthalmology. There were no statistical differences in disqualifications for gender or pathway of entry (civilian vs. serving personnel).DISCUSSION: Major categories of medical attrition were similar to that of other nations, yet the published literature in this area is surprisingly tenuous. Given the desire for evidence-based medical selection standards, it is important for regular review of processes and standards such that the risks of known physiological challenges are judiciously weighed with the benefits of a large, diverse pool of selection as well as force structure and recruitment demand.Adams MS, Goldie CE, Gaydos SJ. Retrospective analysis of medical attrition for pilot applicants to the British Army Air Corps. Aerosp Med Hum Perform. 2023; 94(12):939-943.

PMID:38176043 | DOI:10.3357/AMHP.6342.2023

J Appl Clin Med Phys. 2024 Jan 4:e14258. doi: 10.1002/acm2.14258. Online ahead of print.

ABSTRACT

PURPOSE: We aimed to perform the commissioning and clinical evaluation of myQA SRS detector array for patient-specific quality assurance (PSQA) of stereotactic radiosurgery (SRS)/ stereotactic body radiotherapy (SBRT) plans.

METHODS: To perform the commissioning of myQA SRS, its dose linearity, dose-rate dependence, angular dependence, and field-size dependence were investigated. Ten SBRT plans were selected for clinical evaluation: 1) Common clinical deviations based on the original SBRT plan (Plan0), including multileaf collimator (MLC) positioning deviation and treatment positioning deviation were introduced. 2) Compared the performance of the myQA SRS and a high-resolution EPID dosimetry system in PSQA measurement for the SBRT plans. Evaluation parameters include gamma passing rate (GPR) and distance-to-agreement (DTA) pass rate (DPR).

RESULTS: The dose linearity, angle dependence, and field-size dependence of myQA SRS system exhibit excellent performance. The myQA SRS is highly sensitive in the detection of MLC deviations. The GPR of (3%/1 mm) decreases from 90.4% of the original plan to 72.7%/62.9% with an MLC outward/inward deviation of 3 mm. Additionally, when the setup error deviates by 1 mm in the X, Y, and Z directions with the GPR of (3%/1 mm) decreasing by an average of -20.9%, -25.7%, and -24.7%, respectively, and DPR (1 mm) decreasing by an average of -33.7%, -32.9%, and -29.8%. Additionally, the myQA SRS has a slightly higher GPR than EPID for PSQA, However, the difference is not statistically significant with the GPR of (3%/1 mm) of (average 90.4%% vs. 90.1%, p = 0.414).

CONCLUSION: Dosimetry characteristics of the myQA SRS device meets the accuracy and sensitivity requirement of PSQA for SRS/SBRT treatment. The dose rate dependence should be adequately calibrated before its application and a more stringent GPR (3%/1 mm) evaluation criterion is suggested when it is used for SRS/SBRT QA.

PMID:38175960 | DOI:10.1002/acm2.14258

Hum Vaccin Immunother. 2023 Dec 15;19(3):2278927. doi: 10.1080/21645515.2023.2278927. Epub 2023 Nov 21.

ABSTRACT

Varicella is an acute, highly contagious disease in susceptible individuals and is preventable through vaccination. This study aimed to determine the impact of varicella vaccination on hospitalizations and complications at a pediatric reference hospital in Panama before and after the vaccine introduction. This descriptive ecological study analyzed clinical records of patients diagnosed with varicella through a retrospective and interrupted time series analysis. An autoregressive integrated moving average model was built to compare the incidence rates observed after vaccination with those expected rates derived from the model. A statistical model was fitted to the observed interrupted time series data by regression and used to predict future trends. The mean difference in varicella hospital discharges before and after the introduction of the varicella vaccine was 47%. The rate of hospitalizations for varicella decreased to 52.3%. A declining trend in varicella hospitalizations was observed from 2015 after vaccine introduction in 2014. Complications in vaccinated patients were secondary skin and soft tissue infection, possibly due to bacterial superinfection. The impact of varicella vaccination on reducing varicella hospital discharges reported at a pediatric reference hospital in Panama was confirmed.

PMID:38175951 | DOI:10.1080/21645515.2023.2278927

Adv Mater. 2024 Jan 4:e2309351. doi: 10.1002/adma.202309351. Online ahead of print.

ABSTRACT

Tunnel oxide passivated contacts (TOPCon) have recently gained interest as a way to increase the energy conversion efficiency of silicon solar cells, and the International Technology Roadmap of Photovoltaics forecasts TOPCon to become an important technology despite a few remaining challenges. To review the recent development of TOPCon cells, we have compiled a dataset of all device data found in the current literature, which sums up to 405 devices from 131 papers. This may seem like a surprisingly small number of cells given the recent interest in the TOPCon architecture, but it illustrates a problem of data dissemination in the field. Notwithstanding the limited number of cells, there is a great diversity in cell manufacturing procedures, and we observe a gradual increase in performance indicating that the field has not yet converged on a set of best practices. By analyzing the data using statistical methods and machine learning (ML) algorithms, we were able to reinforces some commonly held hypotheses related to the performance differences between different device architectures. We also identify a few more unintuitive feature combinations that would be of interest for further experimentally studies. This work also aims to inspire improvements in data management and dissemination within the TOPCon community, which would further increase the value of statistical analysis like this as well as enable a larger part of the ML toolbox to be used. This article is protected by copyright. All rights reserved.

PMID:38175915 | DOI:10.1002/adma.202309351

MMWR Morb Mortal Wkly Rep. 2024 Jan 5;72(5253):1394. doi: 10.15585/mmwr.mm725253a6.

NO ABSTRACT

PMID:38175812 | DOI:10.15585/mmwr.mm725253a6

Interdiscip Cardiovasc Thorac Surg. 2024 Jan 4:ivae001. doi: 10.1093/icvts/ivae001. Online ahead of print.

ABSTRACT

OBJECTIVES: Despite robotic-assisted (RATS) lobectomy is on the rise in Europe, the majority of lobectomies in Germany are still performed with an open or thoracoscopic (VATS) approach. Empirical evidence in favour of RATS lobectomy is inconsistent. This retrospective cohort study investigates the impact of RATS lobectomy compared with OPEN (open thoracic surgery) and VATS lobectomy on short-term outcomes in Germany using multicentre real-world data.

METHODS: Anonymized routine data from Germany from 2018 to 2020 were retrospectively analyzed. These data were provided by 61 German hospitals. Propensity Score Matching (PSM) with subsequent Generalized Linear Models (GLM) was performed for statistical analysis. Additionally, in order to test the robustness of the results, multivariable regression analyses with cluster robust standard errors were used.

RESULTS: 2,498 patients with lobectomy were identified: In 1,345 patients OPEN, in 983 VATS and 170 a RATS lobectomy was performed. RATS-compared to OPEN and VATS-reduced length of stay by 28% or 4.2 days [CI: 2.9; 5.4] and by 13% or 1.6 days [CI: 0.2; 3.0], respectively. The risk of pneumonia was reduced by 5.3 percentage points in the RATS group compared to both OPEN and VATS (p = 0.07/0.01). RATS-compared to an open approach-reduces the risk of blood transfusions by 8.8 percentage points (p < 0.001) and length of stay on the ICU (p < 0.001).

CONCLUSION: This study provides strong support that RATS lobectomy outperforms OPEN or VATS lobectomy in terms of hospital length of stay, and short-term in-hospital postoperative complications in the real-world scenario in Germany.

PMID:38175785 | DOI:10.1093/icvts/ivae001