Category: Statistics

Health Econ. 2022 Feb 17. doi: 10.1002/hec.4475. Online ahead of print.

ABSTRACT

When measuring preferences, discrete choice experiments (DCEs) typically assume that respondents consider all available information before making decisions. However, many respondents often only consider a subset of the choice characteristics, a heuristic called attribute non-attendance (ANA). Failure to account for ANA can bias DCE results, potentially leading to flawed policy recommendations. While conventional latent class logit models have most commonly been used to assess ANA in choices, these models are often not flexible enough to separate non-attendance from respondents’ low valuation of certain attributes, resulting in inflated rates of ANA. In this paper, we show that semi-parametric mixtures of latent class models can be used to disentangle successfully inferred non-attendance from respondent’s “weaker” taste sensitivities for certain attributes. In a DCE on the job preferences of health workers in Ethiopia, we demonstrate that such models provide more reliable estimates of inferred non-attendance than the alternative methods currently used. Moreover, since we find statistically significant variation in the rates of ANA exhibited by different health worker cadres, we highlight the need for well-defined attributes in a DCE, to ensure that ANA does not result from a weak experimental design.

PMID:35178825 | DOI:10.1002/hec.4475

Phytother Res. 2022 Feb 17. doi: 10.1002/ptr.7422. Online ahead of print.

ABSTRACT

Rheumatoid arthritis (RA) is a chronic inflammatory disease that leads to cartilage damage with mostly accompanied by metabolic disorders. This study aimed to investigate the effects of curcumin supplementation on metabolic parameters (lipid profile and glycemic indices), inflammatory factors, visfatin levels, and obesity values in women with RA. This randomized, double-blind, placebo-controlled clinical trial was conducted on 48 women with RA. The patients were treated with curcumin (500 mg once a day) or placebo for 8 weeks. Fasting blood samples, anthropometric measurements, dietary intakes, and physical activity levels of subjects were collected at baseline and the end of the study. Curcumin supplementation significantly decreased homeostatic model assessment for insulin resistance (HOMA-IR), erythrocyte sedimentation rate, serum levels of high-sensitivity C-reactive protein and triglycerides, weight, body mass index, and waist circumference of patients compared with the placebo at the end of the study (p < .05 for all). HOMA-IR and triglyceride levels significantly increased within the placebo group. Changes in fasting blood sugar, insulin, other lipids profile, and visfatin levels were not significant in any of the groups (p > .05). These results support the consumption of curcumin, as a part of an integrated approach to modulate metabolic factors, inflammation, and adiposity in women with RA.

PMID:35178811 | DOI:10.1002/ptr.7422

Microsc Res Tech. 2022 Feb 17. doi: 10.1002/jemt.24078. Online ahead of print.

ABSTRACT

To evaluate the caries-affected dentin and composite-resin interface with scanning electron microscopy (SEM) after different caries removal methods in human molars. Twelve with extensive approximal caries lesions that did not reach the pulp and five caries-free molars (control group [CG]) were used. Carious teeth were divided into four experimental groups: Atraumatic Restorative Treatment (ART), Rotary Instrument (RI), Photo-Ablation, and Papain-Based Enzymatic Gel (Brix 3000®, Brix, Brazil). Class II slot cavities were prepared with RI in the CG. Then all caries removed teeth and control groups were restored (All-Bond Universal, BISCO, USA; Clearfil MajestyES-2, Kuraray, Japan). Specimens were prepared for SEM examinations. Hybrid layer (HL) thicknesses were measured using ImageJ programme. Gap measurements were performed with micro-CT. Data were analyzed with ANOVA and posthoc Dunnett’s t-tests (p < .05). The highest HL thickness was found in Photo-Ablation Group, and a statistically significant difference was observed among the control and experimental groups (p < .05). The lowest HL thickness was measured in the Enzymatic Gel Group. In terms of internal gap formation, CG showed statistically significant differences compared to the other groups (p < .05). The highest internal gap was observed in RI Group, while the lowest gap was observed in CG. According to SEM, a uniform HL and resin tags were seen in the CG. Smear layer, irregular HL, and gap formation were observed in ART Group. In RI Group, nonuniform HL formation and resin tags were observed. In Photo-Ablation Group, a uniform HL without smear layer and internal gap was observed. In the Enzymatic Gel Group, both opened dentinal tubules, and melting-like formations were observed on the dentin surface. Especially melting-like formations were observed in peritubular dentin. It can be concluded that all caries removal methods except rotary instrumentation were conservative methods, which preserve more healthy dental tissues.

PMID:35178808 | DOI:10.1002/jemt.24078

Scand J Med Sci Sports. 2022 Feb 17. doi: 10.1111/sms.14144. Online ahead of print.

ABSTRACT

Individuals at risk of Developmental Coordination Disorder (DCD) have low levels of physical activity in childhood due to impaired motor competence, however physical activity levels in adulthood have not been established. This study sought to determine the impact of DCD risk on physical activity levels in adults using accelerometry measurement. Participants (n=656) from the Arvo Ylppö Longitudinal Study cohort had their motor competence assessed at the age of five years, and their physical activity quantified via device assessment at the age of 25 years. Between group differences were assessed to differentiate physical activity measures for individuals based on DCD risk status, with general linear modelling performed to control for the effects of sex, body mass index (BMI), and maternal education. Participants at risk of DCD were found to have a lower total number of steps (d=0.3, p=.022) than those not at risk. Statistical modelling indicated that DCD risk status increased time spent in sedentary light activity (β=0.1, 95% CI 0.02 to 0.3, p=.026) and decreased time spent in vigorous physical activity via interaction with BMI (β=0.04, 95% CI 0.001 to 0.1, p=.025). Sensitivity analysis found that visuomotor impairment did not significantly impact physical activity but did increase the role of DCD risk status in some models. This 20-year-longitudinal study indicated that DCD risk status continues to negatively impact on levels of physical activity into early adulthood.

PMID:35178792 | DOI:10.1111/sms.14144

Stat Med. 2022 Feb 17. doi: 10.1002/sim.9334. Online ahead of print.

ABSTRACT

High-throughput experiments are an essential part of modern biological and biomedical research. The outcomes of high-throughput biological experiments often have a lot of missing observations due to signals below detection levels. For example, most single-cell RNA-seq (scRNA-seq) protocols experience high levels of dropout due to the small amount of starting material, leading to a majority of reported expression levels being zero. Though missing data contain information about reproducibility, they are often excluded in the reproducibility assessment, potentially generating misleading assessments. In this article, we develop a regression model to assess how the reproducibility of high-throughput experiments is affected by the choices of operational factors (eg, platform or sequencing depth) when a large number of measurements are missing. Using a latent variable approach, we extend correspondence curve regression, a recently proposed method for assessing the effects of operational factors to reproducibility, to incorporate missing values. Using simulations, we show that our method is more accurate in detecting differences in reproducibility than existing measures of reproducibility. We illustrate the usefulness of our method using a single-cell RNA-seq dataset collected on HCT116 cells. We compare the reproducibility of different library preparation platforms and study the effect of sequencing depth on reproducibility, thereby determining the cost-effective sequencing depth that is required to achieve sufficient reproducibility.

PMID:35178743 | DOI:10.1002/sim.9334

Int J Health Plann Manage. 2022 Feb 17. doi: 10.1002/hpm.3439. Online ahead of print.

ABSTRACT

BACKGROUND: Women empowerment has been viewed as a good strategy in the reduction of global maternal morbidity and mortality. Most of the recent studies in Uganda have focussed on antenatal care (ANC) frequency and the associated factors with no focus on the effect of women empowerment. Our study aims at examining the prevalence of optimal access to ANC by considering the timing of initiation, type of ANC provider and ANC frequency and their association with women empowerment.

METHODS: We used Uganda Demographic and Health Survey 2016 data of 9957 women aged 15-49 years. Multistage stratified sampling was used to select study participants and we conducted multivariable logistic regression to establish the association between women empowerment and access to ANC using Statistical package for the social sciences version 25.

RESULTS: Out of 9957 women, 2953 (29.7%: 95% CI: 28.5.0-30.2) had initiated ANC in first trimester, 6080 (61.1%: 95% CI: 60.4-62.3) had 4 or more ANC contacts, and 9880 (99.2%: 95% CI: 99.0-99.3) had received ANC from a skilled provider. Overall, 2399 (24.1%: 95% CI: 23.0-24.6) had optimal access to ANC. Economic empowerment and exposure to media were the only women empowerment indices that were positively associated with optimal access to ANC. Other factors that were significant include; region, wealth index, age, level of education and working status.

CONCLUSION: To ensure increased access to ANC, policy-makers and other stakeholders should prioritise the use of mass media in maternal health programs, equitable allocation of the limited financial resources with a focus on older, poor and uneducated women.

PMID:35178763 | DOI:10.1002/hpm.3439

Stat Med. 2022 Feb 17. doi: 10.1002/sim.9355. Online ahead of print.

ABSTRACT

In phase II oncology trials, two-stage design allowing early stopping for futility and/or efficacy is frequently used. However, this design based on frequentist statistical approaches could not guarantee a high posterior probability of attending the pre-specified clinically interesting rate from a Bayesian perspective. Here, we proposed a new Bayesian design enabling early terminating for efficacy as well as futility. In addition to the clinically uninteresting and interesting response rate, a prior distribution of response rate, the minimum posterior threshold probabilities and the lengths of the highest posterior density intervals were specified in the design. Finally, we defined the feasible design with the highest total effective predictive probability. We studied the properties of the proposed design and applied it to an oncology trial as an example. The proposed design ensured that the observed response rate fell within prespecified levels of posterior probability. The proposed design provides an alternative design to single-arm two-stage trials.

PMID:35178729 | DOI:10.1002/sim.9355

Infection. 2022 Feb 17. doi: 10.1007/s15010-022-01772-4. Online ahead of print.

ABSTRACT

PURPOSE: Since 2020, a SARS-COV2 epidemic has been raging worldwide. The cycle of the PCR test in which the virus is detected is called cycle threshold (CT). The method of obtaining the sample is not detailed in any published study and is based on general guidelines of the CDC. Our contention is that the manner in which the sample is obtained has a dramatic effect on CT values.

METHODS: For each person suspected of having Covid-19 who arrives at the emergency room, two swabs are taken in succession, one according to CDC guidelines and the other according to “Ziv” guidelines. The Ziv method sample collection guidelines determine the depth of penetration, the number of rotations of the swab, and their direction. Each double sample was sent for analysis.

RESULTS: Analysis of the CT results of the sample to results methods and of the Seegene platform clearly found (p = 0.003 and p = 0.001, respectively) that more rigorous sample collection yielded lower CT values.

CONCLUSION: The method of obtaining the samples had a dramatic effect on CT results. Any publication that includes CT results, and certainly studies that discuss CT kinetics, must describe in detail the method by which the samples were obtained. In places where it is also important to detect the onset of illness (airports, hospitals, schools, etc.), it is important to use the Ziv method to reduce the risk of false negatives.

PMID:35178676 | DOI:10.1007/s15010-022-01772-4

Biometrics. 2022 Feb 18. doi: 10.1111/biom.13634. Online ahead of print.

ABSTRACT

Combining dependent tests of significance has broad applications but the related p-value calculation is challenging. For Fisher’s combination test, current p-value calculation methods (e.g., Brown’s approximation) tend to inflate the type I error rate when the desired significance level is substantially less than 0.05. The problem could lead to significant false discoveries in big data analyses. This paper provides two main contributions. First, it presents a general family of Fisher type statistics, referred to as the GFisher, which covers many classic statistics, such as Fisher’s combination, Good’s statistic, Lancaster’s statistic, weighted Z-score combination, etc. The GFisher allows a flexible weighting scheme, as well as an omnibus procedure that automatically adapts proper weights and the statistic-defining parameters to a given data. Second, the paper presents several new p-value calculation methods based on two novel ideas: moment-ratio matching and joint-distribution surrogating. Systematic simulations show that the new calculation methods are more accurate under multivariate Gaussian, and more robust under the generalized linear model and the multivariate t-distribution. The applications of the GFisher and the new p-value calculation methods are demonstrated by a gene-based SNP-set association study. Relevant computation has been implemented to an R package GFisher available on the Comprehensive R Archive Network. This article is protected by copyright. All rights reserved.

PMID:35178716 | DOI:10.1111/biom.13634

Clin Exp Pediatr. 2022 Feb 17. doi: 10.3345/cep.2021.00962. Online ahead of print.

ABSTRACT

The literature review aimed to analyze studies assessing the motor abilities of children with attention deficit hyperactivity disorder (ADHD) using the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP). The PubMed, OVID, Cochrane, and PEDro databases were searched for relevant articles published between February 2003 and September 2021. Despite the retrieval of limited studies, most included in this review were of fair to good quality. The diagnostic criteria for ADHD adhered to Diagnostic and Statistical Manual of Mental Disorders standards. The BOTMP has been used diversely in various countries, has been translated into various languages, is administered by various qualified medical professionals on children with variants of ADHD, with the long form of the tool used more widely than its short form. The motor performance of children with ADHD was better than that of children with other developmental disorders, but children with ADHD underperformed compared to their age-matched typically developing peers. Although the BOTMP tool has been widely used to evaluate the motor performance of children with various disabilities, our understanding of the motor repertoire of children with ADHD is inadequate. Future research can aim to use the BOTMP to better understand the motor repertoire of children with ADHD to aid their overall rehabilitation.

PMID:35176833 | DOI:10.3345/cep.2021.00962