Categories
Nevin Manimala Statistics

A continuous statistical-geometric framework for normative and impaired gaits

J R Soc Interface. 2022 Nov;19(196):20220402. doi: 10.1098/rsif.2022.0402. Epub 2022 Nov 2.

ABSTRACT

A quantitative analysis of human gait patterns in space-time provides an opportunity to observe variability within and across individuals of varying motor capabilities. Impaired gait significantly affects independence and quality of life, and thus a large part of clinical research is dedicated to improving gait through rehabilitative therapies. Evaluation of these paradigms relies on understanding the characteristic differences in the kinematics and underlying biomechanics of impaired and unimpaired locomotion, which has motivated quantitative measurement and analysis of the gait cycle. Previous analysis has largely been limited to a statistical comparison of manually selected pointwise metrics identified through expert knowledge. Here, we use a recent statistical-geometric framework, elastic functional data analysis (FDA), to decompose kinematic data into continuous ‘amplitude’ (spatial) and ‘phase’ (temporal) components, which can then be integrated with established dimensionality reduction techniques. We demonstrate the utility of elastic FDA through two unsupervised applications to post-stroke gait datasets. First, we distinguish between unimpaired, paretic and non-paretic gait presentations. Then, we use FDA to reveal robust, interpretable groups of differential response to exosuit assistance. The proposed methods aim to benefit clinical practice for post-stroke gait rehabilitation, and more broadly, to automate the quantitative analysis of motion.

PMID:36321374 | DOI:10.1098/rsif.2022.0402

Categories
Nevin Manimala Statistics

ANALYSES OF SOME CALL FACTORS AFFECTING SAR LEVELS OF GSM MOBILE PHONES USED IN GHANA

Radiat Prot Dosimetry. 2022 Nov 1:ncac206. doi: 10.1093/rpd/ncac206. Online ahead of print.

ABSTRACT

In response to mounting radiofrequency health concerns, this study was constituted to provide critical scientific data and assess any potential exposure from global system for mobile communication mobile phones. Specific absorption rate (SAR) from phones approved by the regulator and untested/unapproved phones were measured with a ComoSAR system. The maximum 10 g SAR (0.51 W/kg) and 1 g SAR (0.99 W/kg) measured were 25 and 62% of the International Commission on Non-Ionizing Radiation Protection and Federal Communication Commission limits, respectively. The approved phone produced statistically significant higher SAR values relative to the untested phone. SAR values of the right ear were relatively higher. All maximum SAR values were recorded on the right ear. The regulatory approval status of the phone, phone’s orientation to the head, operating frequency channel and in which ear (right or left) the phone is used influenced the SAR measured. The SAR values of the approved phone compared favourably with similar studies while the unapproved phone does not.

PMID:36321330 | DOI:10.1093/rpd/ncac206

Categories
Nevin Manimala Statistics

Latent multinomial models for extended batch-mark data

Biometrics. 2022 Nov 2. doi: 10.1111/biom.13789. Online ahead of print.

ABSTRACT

Batch marking is common and useful for many capture-recapture studies where individual marks cannot be applied due to various constraints such as timing, cost, or marking difficulty. When batch marks are used, observed data are not individual capture histories but a set of counts including the numbers of individuals first marked, marked individuals that are recaptured, and individuals captured but released without being marked (applicable to some studies) on each capture occasion. Fitting traditional capture-recapture models to such data requires one to identify all possible sets of capture-recapture histories that may lead to the observed data, which is computationally infeasible even for a small number of capture occasions. In this paper, we propose a latent multinomial model to deal with such data, where the observed vector of counts is a non-invertible linear transformation of a latent vector that follows a multinomial distribution depending on model parameters. The latent multinomial model can be fitted efficiently through a saddlepoint approximation based maximum likelihood approach. The model framework is very flexible and can be applied to data collected with different study designs. Simulation studies indicate that reliable estimation results are obtained for all parameters of the proposed model. We apply the model to analysis of golden mantella data collected using batch marks in central Madagascar. This article is protected by copyright. All rights reserved.

PMID:36321329 | DOI:10.1111/biom.13789

Categories
Nevin Manimala Statistics

Cerebral 18 F-fluorodeoxyglucose metabolism alteration of reward- and motivation-related regions in groups of different BMI classifications

Obesity (Silver Spring). 2022 Nov;30(11):2213-2221. doi: 10.1002/oby.23553.

ABSTRACT

OBJECTIVE: This study explored the relationship between BMI and regional cerebral glucose metabolism and explicitly detected regions with significant differences in cerebral metabolism using positron emission tomography (PET)/magnetic resonance imaging in the resting state.

METHODS: Corresponding PET images acquired from 220 participants were sorted into four groups according to Asian BMI standards: underweight, normal weight, overweight, and obesity. Pearson correlation coefficient analysis was performed to assess the association between BMI and standard uptake value. The regional cerebral glucose metabolism was measured in the fasted state. The PET images were analyzed using statistical parameter maps. One-way ANOVA was used to explore differences in the standard uptake value as an indicator of regional cerebral glucose metabolism.

RESULTS: This study found that lower cerebral glucose metabolism in reward- and motivation-related regions was accompanied by more severe obesity and that regional cerebral glucose metabolism activities were negatively correlated with BMI. In addition, more severe obesity was accompanied by a larger range of areas with significant differences independent of current dietary status.

CONCLUSIONS: These findings suggest that the reward and motivation circuits may be a factor regulating energy balance and influencing the degree of obesity.

PMID:36321272 | DOI:10.1002/oby.23553

Categories
Nevin Manimala Statistics

The effects of hormonal contraceptive use on sleep in women: A systematic review and meta-analysis

J Sleep Res. 2022 Nov 1:e13757. doi: 10.1111/jsr.13757. Online ahead of print.

ABSTRACT

Hormonal contraceptives are some of the most widely used medications worldwide, but studies on their effects on sleep are contradictory, with some reporting a sleep-promoting effect, while others a sleep-inhibiting effect. Our objective was, therefore, to undertake a systematic review and meta-analysis of the literature on this subject to try to clarify their effects. A search was conducted in three databases (PubMed, Scopus and Web of Science). Only studies evaluating hormonal contraception use were considered eligible, and both objective and subjective sleep-related outcomes were considered. Individual effect size was calculated for each article, and meta-analyses were performed using a DerSimonian and Laird random effects method. The initial search identified 2076 articles, of which 13 met the criteria for the study after full text evaluation. A total of 33 meta-analyses were performed, three of them related to subjective measures and 30 considering data from polysomnography. The only statistically significant result between contraceptive users and non-contraceptive users was observed in respect of wake after sleep onset, which was 7 min shorter among contraceptive users (-7.12 [-12.80; -1.44]; I2 = 65%; p = 0.01). In conclusion, hormonal contraceptives are not associated with clinically relevant changes in sleep patterns in women.

PMID:36319606 | DOI:10.1111/jsr.13757

Categories
Nevin Manimala Statistics

The impact of body mass index on patient radiation dose in general radiography

J Radiol Prot. 2022 Nov 1. doi: 10.1088/1361-6498/ac9f1f. Online ahead of print.

ABSTRACT

The aim of the study was to determine the influence of body mass index (BMI) on Dose-Area Product (DAP) and effective dose (ED) in overweight and obese patients. We also wanted to determine the typical dose values as well as suggest adjustments of clinical practice for overweight and obese patients. In this study 597 patients referred for imaging of the chest in PA and lateral projection, lumbar spine AP and lateral projection, imaging of the pelvis, knee in AP and lateral projection, and shoulder in AP projection were considered. For each examination, the image field size, tube voltage, mAs product, source-to-image receptor distance and values of DAP were collected. Based on BMI patients were divided into three groups (normal weight, overweight and obese). At the end, PCXMC 2.0 software was used to calculate the effective dose. The study showed a statistically significant DAP and ED increase in overweight and obese patients by 28.9% up to 275.4% in the case of DAP and an increase of ED from 11.0% to 241.9% in all mentioned examinations except knee and shoulder imaging. Typical DAP values ranged from 2.2 to 54.8 µGym2 for normal weight patients, from 2.2 to 87.6 µGym2 for overweight patients, and from 2.2 to 172.5 µGym2 for obese patients. Spearman’s correlation coefficient showed from very weak to very strong correlations when comparing BMI and DAP as well as comparing BMI and ED. A strong and very strong correlation was found in case of the examinations of the torso (except for the comparison of BMI and ED in case of lateral lumbar spine projection).

PMID:36319605 | DOI:10.1088/1361-6498/ac9f1f

Categories
Nevin Manimala Statistics

Impact of Institutional Universal Microsatellite-Instability (MSI) Reflex Testing on Molecular Profiling Differences Between Younger and Older Patients with Colorectal Cancer

Clin Colorectal Cancer. 2022 Sep 30:S1533-0028(22)00104-9. doi: 10.1016/j.clcc.2022.09.004. Online ahead of print.

ABSTRACT

INTRODUCTION: DNA mismatch repair deficient (dMMR) or microsatellite instability-high (MSI-H) colorectal cancer (CRC) is found in about 15% of early-stage diseases and 5% of metastatic diseases. We reviewed a large, single-institutional database after implementation of universal reflex dMMR/MSI-H testing in CRC to compare profiles of younger (≤50) and older (>50) patients.

PATIENTS AND METHODS: Between 2009 and 2017, all patients diagnosed with CRC at the University of Florida underwent reflex somatic tumor testing for dMMR by immunohistochemistry (MLH1, PMS2, MSH2, MSH6), MSI by PCR, and Next-Generation Sequencing. Statistical analysis was conducted with 2-sample comparison tests and logistic regression models.

RESULTS: There were 375 patients included in the final analysis. Patients were grouped as younger (ages ≤50 years-old; n = 80) or older (>50 years-old; n = 295). Compared to tumors from older patients, tumors from younger patients were less likely to be dMMR/MSI-H (12.5% vs. 21.4%, P = .013) and less likely to have a BRAF mutation (1.5% vs. 16.1%, P = .002). BRAF mutation status was highly associated with MMR status; BRAF-mutated tumors were 29.7 times more likely than BRAF-WT tumors to be dMMR/MSI-H (P = < .001, 95% CI 11.3-78.3).

CONCLUSIONS: Tumors of younger patients were less likely than tumors of older patients to have a dMMR/MSI-H or BRAF mutation. Universal MMR/MSI testing in our dataset identified a relatively large population of older patients with sporadic CRC who were eligible for immunotherapy.

PMID:36319582 | DOI:10.1016/j.clcc.2022.09.004

Categories
Nevin Manimala Statistics

Tumor risk markers in recurrent respiratory papillomatosis

Braz J Otorhinolaryngol. 2022 Oct 20:S1808-8694(22)00172-0. doi: 10.1016/j.bjorl.2022.10.049. Online ahead of print.

ABSTRACT

OBJECTIVES: This study aims to investigate the pattern of immunoexpression of proteins p16, p53 and Ki-67 in RRP, as well as to evaluate its influence on the number of surgeries that patients have undergone to date and to analyze the benefit of immunohistochemistry in this disease.

METHODS: Clinical-demographic data and tumor samples were obtained from 33 patients with RRP. The expression of proteins p16, p53 and Ki-67 was analyzed by immunohistochemical method.

RESULTS: Most patients had already undergone more than one surgery. The p16 marker was negative in 24.2% of the cases, with little positivity in 27.3% of the cases, moderate in 36.4% and intense in 12.1%. The p53 marker was positive in all cases, with little immunoexpression in 39.4% of cases, moderate in 36.4% and intense in 24.2%. The Ki-67 marker showed nuclear positivity in all lesions, although in varying degrees, with a mean proliferative index ± SD (standard deviation) of 51.7 ± 26.

CONCLUSIONS: The papillomatous lesions had varying degrees of immunoexpression of proteins p16, p53 and Ki-67, but no specific immunohistochemical pattern was observed. It was found, with statistical difference, that the number of surgeries was higher in cases with greater intensity of p53 expression, without correlation with the other markers. The benefit of immunohistochemistry in recurrent respiratory papillomatosis may lie in the prognostic assessment. However, further studies are needed to evaluate the use of this technique for this purpose.

LEVEL OF EVIDENCE: 4.

PMID:36319567 | DOI:10.1016/j.bjorl.2022.10.049

Categories
Nevin Manimala Statistics

Volumetric Quantitative Contrast-enhanced Ultrasonography Evaluation of Complex Renal Cysts: An Adjunctive Metric to the Bosniak Classification System to Predict Malignancy

Eur Urol Focus. 2022 Oct 29:S2405-4569(22)00232-2. doi: 10.1016/j.euf.2022.10.004. Online ahead of print.

ABSTRACT

BACKGROUND: Management of complex renal cysts is guided by the Bosniak classification system, which may be inadequate for risk stratification of patients for intervention. Fractional tumor vascularity (FV) calculated from volumetric contrast-enhanced ultrasound (CEUS) images may provide additional useful information.

OBJECTIVE: To evaluate CEUS and FV calculation for risk stratification of patients with complex renal cysts.

DESIGN, SETTING, AND PARTICIPANTS: This was a pilot prospective study with institutional review board approval involving patients undergoing surgery for Bosniak IIF-IV complex renal cysts. CEUS was performed preoperatively on the day of surgery with two-dimensional (2D) and three-dimensional (3D) imaging and sulfur hexafluoride lipid-type A microspheres as the ultrasound contrast agent.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: A custom MATLAB program was used to select regions of interest on CEUS scans. FV was calculated according to FV = 1 – (total nonenhancing area/total lesion area). We assessed the ability of 2D- and 3D-derived percentage FV (2DFV%, and 3DFV%) and Bosniak classification schemes (pre-2019 [P2019B] and post-2019 [B2019]) to predict malignancy, aggressive histology, and upstaging on surgical pathology. Performance was assessed as area under the receiver operating characteristic curve (AUC).

RESULTS AND LIMITATIONS: Twenty eligible patients were included in final analysis, of whom 85% (n = 17) had Bosniak IV cysts and 85% (n = 17) had malignant disease on final pathology. Four (24%) of the malignant lesions were International Society of Urological Pathology grade 3-4. The AUC for predicting malignancy was 0.980, 0.824, 0.863, and 0.824 with P2019B, B2019, 2DFV%, and 3DFV%, respectively. When the Bosniak classification was combined with FV%, three models had an AUC of 1, while the combined 2DFV% + B2019 model had AUC of 0.980.

CONCLUSIONS: FV is a novel metric for evaluating complex cystic renal masses and enhances the ability of the Bosniak classification system to predict malignancy. This metric may serve as an adjunct in risk stratification for surgical intervention. Further prospective evaluation is warranted.

PATIENT SUMMARY: Cysts in the kidney are currently classified using a scheme called the Bosniak system. We assessed measurement of the percentage of vascular tissue (called fractional vascularity) in cysts on a special type of ultrasound scan. This promising test adds information when combined with the Bosniak system and can help in guiding appropriate treatment.

PMID:36319560 | DOI:10.1016/j.euf.2022.10.004

Categories
Nevin Manimala Statistics

5α-reductase inhibitors and the risk of bladder cancer in a large, population-based cohort

Urol Oncol. 2022 Oct 29:S1078-1439(22)00312-X. doi: 10.1016/j.urolonc.2022.09.004. Online ahead of print.

ABSTRACT

PURPOSE: The ability of 5α-reductase inhibitors (5ARI) to reduce the risk of new onset bladder cancer (BC) has been studied with variable results. Our objective was to conduct a retrospective cohort population-based study to evaluate the association between 5ARI use, BC diagnosis, and BC mortality.

PATIENTS AND METHODS: We used routinely collected health care data from Ontario, Canada. Men ≥66 years of age with a prescription for a 5ARI were matched to non-5ARI users. Matching was done using a propensity score of selected covariates to make 96 different covariates comparable. We measured 5 additional baseline variables which may have impacted the risk of future BC diagnosis: prior cystoscopy, urine cytology, urinalysis, gross hematuria episodes, and transurethral resection of a bladder lesion. Only the first period of continuous usage of 5ARIs was considered. The prespecified at-risk period for outcomes started 1 year after initiating therapy and ended at the last date of 5ARI exposure + 1 year.

RESULTS: We identified 93,197 men who initiated 5ARI therapy (52% dutasteride, and 48% finasteride) between 2003 and 2013 and matched them 1:1 to men who did not start a 5ARI. The median at-risk period for the 5ARI group was 1.68 years (interquartile range 1.00, 4.27). With adjustment for the variables related to prior BC investigations there was no significant difference in BC diagnosis (hazard ratio [HR] 1.05, 95% confidence interval [CI] 0.82-1.32) during the period of 0 to <2 years of 5ARI use; however, after ≥2 years of 5ARI use, the risk of BC diagnosis was significantly lower among the 5ARI group (HR 0.82, 95% CI 0.79-0.94). In a similarly adjusted model, BC mortality was lower among 5ARI users, but no longer statistically significant (HR 0.82, 95% CI 0.65, 1.02). When stratified by type of 5ARI, finasteride significantly reduced the risk of BC diagnosis after ≥2 years of continuous use (HR 0.86, 95% CI 0.76, 0.96); however, dutasteride did not (HR 0.92, 95% CI 0.83, 1.03).

CONCLUSIONS: In a large cohort of men, the use of a 5ARI was associated with a significantly decreased the risk of BC diagnosis after more than 2 years of continuous therapy.

PMID:36319553 | DOI:10.1016/j.urolonc.2022.09.004