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Nevin Manimala Statistics

Bounds for the weight of external data in shrinkage estimation

Biom J. 2021 Feb 25. doi: 10.1002/bimj.202000227. Online ahead of print.

ABSTRACT

Shrinkage estimation in a meta-analysis framework may be used to facilitate dynamical borrowing of information. This framework might be used to analyze a new study in the light of previous data, which might differ in their design (e.g., a randomized controlled trial and a clinical registry). We show how the common study weights arise in effect and shrinkage estimation, and how these may be generalized to the case of Bayesian meta-analysis. Next we develop simple ways to compute bounds on the weights, so that the contribution of the external evidence may be assessed a priori. These considerations are illustrated and discussed using numerical examples, including applications in the treatment of Creutzfeldt-Jakob disease and in fetal monitoring to prevent the occurrence of metabolic acidosis. The target study’s contribution to the resulting estimate is shown to be bounded below. Therefore, concerns of evidence being easily overwhelmed by external data are largely unwarranted.

PMID:33629749 | DOI:10.1002/bimj.202000227

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Nevin Manimala Statistics

Bootstrap confidence intervals for principal covariates regression

Br J Math Stat Psychol. 2021 Feb 25. doi: 10.1111/bmsp.12238. Online ahead of print.

ABSTRACT

Principal covariate regression (PCOVR) is a method for regressing a set of criterion variables with respect to a set of predictor variables when the latter are many in number and/or collinear. This is done by extracting a limited number of components that simultaneously synthesize the predictor variables and predict the criterion ones. So far, no procedure has been offered for estimating statistical uncertainties of the obtained PCOVR parameter estimates. The present paper shows how this goal can be achieved, conditionally on the model specification, by means of the bootstrap approach. Four strategies for estimating bootstrap confidence intervals are derived and their statistical behaviour in terms of coverage is assessed by means of a simulation experiment. Such strategies are distinguished by the use of the varimax and quartimin procedures and by the use of Procrustes rotations of bootstrap solutions towards the sample solution. In general, the four strategies showed appropriate statistical behaviour, with coverage tending to the desired level for increasing sample sizes. The main exception involved strategies based on the quartimin procedure in cases characterized by complex underlying structures of the components. The appropriateness of the statistical behaviour was higher when the proper number of components were extracted.

PMID:33629738 | DOI:10.1111/bmsp.12238

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Nevin Manimala Statistics

Top-Down Attention Guidance Shapes Action Encoding in the pSTS

Cereb Cortex. 2021 Feb 25:bhab029. doi: 10.1093/cercor/bhab029. Online ahead of print.

ABSTRACT

The posterior superior temporal sulcus (pSTS) is a brain region characterized by perceptual representations of human body actions that promote the understanding of observed behavior. Increasingly, action observation is recognized as being strongly shaped by the expectations of the observer (Kilner 2011; Koster-Hale and Saxe 2013; Patel et al. 2019). Therefore, to characterize top-down influences on action observation, we evaluated the statistical structure of multivariate activation patterns from the action observation network (AON) while observers attended to the different dimensions of action vignettes (the action kinematics, goal, or identity of avatars jumping or crouching). Decoding accuracy varied as a function of attention instruction in the right pSTS and left inferior frontal cortex (IFC), with the right pSTS classifying actions most accurately when observers attended to the action kinematics and the left IFC classifying most accurately when observed attended to the actor’s goal. Functional connectivity also increased between the right pSTS and right IFC when observers attended to the actions portrayed in the vignettes. Our findings are evidence that the attentive state of the viewer modulates sensory representations in the pSTS, consistent with proposals that the pSTS occupies an interstitial zone mediating top-down context and bottom-up perceptual cues during action observation.

PMID:33629729 | DOI:10.1093/cercor/bhab029

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Nevin Manimala Statistics

Comparison of Perceived and Measured Body Composition in a Military Population: An Exploratory Study

Mil Med. 2021 Feb 25:usab085. doi: 10.1093/milmed/usab085. Online ahead of print.

ABSTRACT

INTRODUCTION: Weight status perception (WSP) is the subjective assessment of one’s own body weight. It is not correlated with the body mass index (BMI). People practicing sports, including overweight people, tend to perceive themselves as normal weight. The military is in a paradoxical position between the need to gain muscle mass for professional purposes while respecting BMI standards. Using body composition might be more advantageous than using BMI as part of an individual approach in making a decision about fitness to serve. However, measuring body composition is not easy in current practice, and a bridge between WSP and body composition would make it possible to develop a simple assessment tool.

MATERIALS AND METHODS: This was a prospective, descriptive, cross-sectional study. We collected sociodemographic data, anthropometric data, and WSP.

RESULTS: Thirty-eight subjects were included. Among them, 71.1% were male. Mean age was 31.2 years (SD 8.9). The BMI was greater than 25 for 15 (39.5%) subjects. Twenty-four (63.2%) defined themselves as being overweight. Thirteen were overweight according to fat percentage (Fat%). A significant association (P = .008) was found between WSP and Fat%.

CONCLUSION: We were able to show a statistically significant association between WSP and Fat%. Such an association may be of great interest because the measurement of the Fat%, whatever the method used, is not easy in current practice. A replication of the study in the general population would be of great interest, especially since Fat% is closely associated with the incidence of cardiovascular diseases and many cancers.

PMID:33629720 | DOI:10.1093/milmed/usab085

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Nevin Manimala Statistics

Development and evaluation of a simulation-based mastery learning maintenance of certification course

Gerontol Geriatr Educ. 2021 Feb 25:1-10. doi: 10.1080/02701960.2021.1891417. Online ahead of print.

ABSTRACT

Background/Objectives: To develop and evaluate a post-acute care simulation-based mastery learning (SBML) continuing medical education (CME)/maintenance of certification (MOC) procedure course.Design: Pretest-posttest study of the SBML intervention.Setting: A 2-day post-acute care procedures course.Participants: Sixteen practicing clinicians (5 physicians,11 advanced practice providers). Participants engaged in a skills pretest on knee aspiration/injection, gastrostomy tube removal/replacement, tracheostomy tube exchange, and basic suturing using a checklist created for each procedure. Participants received a didactic on each procedure followed by deliberate practice with feedback. Using the same checklists, participants completed a skills posttest and were required to meet a minimum passing standard (MPS) to obtain CME/MOC credit.Measurements: The MPS for each skills checklist was determined by a multidisciplinary panel of 11 experts. Participants completed surveys on procedure self-confidence and a course evaluation.Results: There was statistically significant improvement between pre- and posttests for all four procedures (p < .001). All participants were able to meet or exceed the MPS for each skill during the 2-day course. Participants’ self-confidence regarding each procedure improved significantly (p < .001).Conclusion: An SBML training course granting CME/MOC credit for post-acute care providers significantly improves performance of knee aspiration/injection, gastrostomy tube removal/replacement, tracheostomy tube exchange, and basic suturing.

PMID:33629646 | DOI:10.1080/02701960.2021.1891417

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Nevin Manimala Statistics

EXPRESS: Reliability of Moral Decision Making: Evidence from the Trolley Dilemma

Q J Exp Psychol (Hove). 2021 Feb 25:17470218211001547. doi: 10.1177/17470218211001547. Online ahead of print.

ABSTRACT

The application of framing effects in the field of moral judgment has offered a golden opportunity to assess the reliability of people’s moral judgments and decisions. To date, however, these studies are still scarce and they suffer from multiple methodological issues. Therefore, the present study aims to provide further insights into the reliability of moral judgments while fixing these methodological shortcomings. In the current study, we employed the classic trolley dilemma moral decision-making paradigm to determine the extent to which moral decisions are susceptible to framing effects. A total of 1040 participants were included in the study. The data revealed that choices of participants did not significantly differ between the two frames. Equivalence tests confirmed that the associated effect size was very small. Further exploratory analyses revealed an unplanned interaction between the framing effect and the target of the framing manipulation. This result became from marginally statistically significant to insignificant following different sensitivity analyses. The implications and limitations of these findings and directions for future research are discussed.

PMID:33629641 | DOI:10.1177/17470218211001547

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Nevin Manimala Statistics

Widespread non-joint pain in early rheumatoid arthritis

Scand J Rheumatol. 2021 Feb 25:1-9. doi: 10.1080/03009742.2020.1846778. Online ahead of print.

ABSTRACT

Objective: The aim of the study was to assess the development of widespread non-joint pain (WNP) in a cohort of patients with early rheumatoid arthritis (RA), the associated health-related quality of life (HRQoL), and clinical and demographic risk factors for WNP.Method: Incident cases with RA, from the Swedish population-based study Epidemiological Investigation of Rheumatoid Arthritis (EIRA), with a follow-up of at least 3 years, constituted the study population. WNP was defined as pain outside the joints in all four body quadrants and was assessed at the 3 year follow-up. Patients who reported WNP were compared to patients without WNP regarding HRQoL, measured by the Short Form-36, at 3 years, and clinical and demographic characteristics at the time of RA diagnosis.Results: A total of 749 patients constituted the study sample, of whom 25 were excluded after reporting already having severe pain before RA diagnosis. At the 3 year follow-up, 8% of the patients reported having WNP as well as statistically significant worse HRQoL. At the time of RA diagnosis, the patients with WNP had worse pain and pain-related features, while no difference was seen in the inflammatory parameters.Conclusion: WNP occurs in a substantial subset of patients with RA, also early in the course of the disease, and the HRQoL for these patients is significantly reduced. Patients who develop WNP at 3 years are already distinguishable at the time of diagnosis by displaying more pronounced pain ratings together with an average level of inflammatory disease activity.

PMID:33629632 | DOI:10.1080/03009742.2020.1846778

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Nevin Manimala Statistics

Resource utilization, work productivity and costs in patients with hidradenitis suppurativa: a cost-of-illness study

Expert Rev Pharmacoecon Outcomes Res. 2021 Feb 25. doi: 10.1080/14737167.2021.1895753. Online ahead of print.

ABSTRACT

Background: Hidradenitis suppurativa (HS) is a potentially disabling, chronic inflammatory skin disease affecting up to 1% of the population in Europe. This study aims to assess the cost-of-illness of HS from a societal perspective in Hungary, and to analyse the predictors of costs.Methods: A multicentre, cross-sectional cost-of-illness study was performed among 200 adult HS patients. We evaluated direct medical (physician consultations, inpatient admissions, medical and surgeries), direct non-medical (transportation and caregiving) and indirect costs (productivity loss).Results: The mean annual cost-of-illness of HS was €6,791 per patient. The main cost components were productivity loss (53.3%), biological treatment (21.5%) and informal care (9.2%). Patients missed, on average, 26 and 63 days from work annually due to absenteeism and presenteeism, respectively. Male sex, more severe disease, gluteal involvement and coexisting inflammatory bowel disease were associated with higher direct medical costs, while lower education level and worse quality-of-life outcomes predicted higher indirect costs.Conclusions: This is the first study to assess both direct and indirect costs in HS patients. HS imposes a substantial burden on patients and society, predominantly arising from productivity loss and biological therapy. Resource utilization data and cost-of-illness estimates provide valuable inputs into cost-effectiveness analyses of health interventions in HS.

PMID:33629618 | DOI:10.1080/14737167.2021.1895753

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Nevin Manimala Statistics

Educational Intervention Reduced Family Medicine Residents’ Intention to Request Diagnostic Tests: Results of a Controlled Trial

Med Decis Making. 2021 Feb 25:272989X21989692. doi: 10.1177/0272989X21989692. Online ahead of print.

ABSTRACT

OBJECTIVE: Dealing with uncertainty is a core competence for physicians. To evaluate the impact of an educational intervention on family medicine residents’ (FMRs’) intention to request diagnostic tests and their attitudes toward uncertainty.

METHODS: Nonrandomized controlled trial. Intervention group (IG) FMRs participated in interactive “dealing with uncertainty” seminars comprising statistical lessons and diagnostic reasoning. Control group (CG) FMRs participated in seminars without in-depth diagnostic lessons. FMRs completed the Dealing with Uncertainty Questionnaire (DUQ), comprising the Diagnostic Action and Diagnostic Reasoning scales. The Physicians’ Reaction to Uncertainty (PRU) questionnaire, comprising 4 scales (Anxiety Due to Uncertainty, Concern about Bad Outcomes, Reluctance to Disclose Uncertainty to Patients, and Reluctance to Disclose Mistakes to Physicians) was also completed. Follow-up was performed 3 months later. Differences were calculated with repeated-measures analysis of variance.

RESULTS: In total, 107 FMRs of the IG and 102 FMRs of the CG participated at baseline and follow-up. The mean (SD) Diagnostic Action scale score decreased from 24.0 (4.8) to 22.9 (5.1) in the IG and increased in the CG from 23.7 (5.4) to 24.1 (5.4), showing significant group difference (P = 0.006). The Diagnostic Reasoning scale increased significantly (P = 0.025) without a significant group difference (P = 0.616), from 19.2 (2.6) to 19.7 (2.4) in the IG and from 18.1 (3.3) to 18.8 (3.2) in the CG. The PRU scale Anxiety Due to Uncertainty decreased significantly (P = 0.029) without a significant group difference (P = 0.116), from 20.5 (4.8) to 18.5 (5.5) in the IG and from 19.9 (5.5) to 19.0 (6.0) in the CG.

CONCLUSION: The structured seminar reduced self-rated diagnostic test requisition. The change in Anxiety Due to Uncertainty and Diagnostic Reasoning might be due to an unspecific accompanying effect of the extra-occupational seminars for residents.

PMID:33629614 | DOI:10.1177/0272989X21989692

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Nevin Manimala Statistics

Defining treatment regimens and lines of therapy using real-world data in oncology

Future Oncol. 2021 Feb 25. doi: 10.2217/fon-2020-1041. Online ahead of print.

ABSTRACT

Retrospective observational research relies on databases that do not routinely record lines of therapy or reasons for treatment change. Standardized approaches to estimate lines of therapy were developed and evaluated in this study. A number of rules were developed, assumptions varied and macros developed to apply to large datasets. Results were investigated in an iterative process to refine line of therapy algorithms in three different cancers (lung, colorectal and gastric). Three primary factors were evaluated and included in the estimation of lines of therapy in oncology: defining a treatment regimen, addition/removal of drugs and gap periods. Algorithms and associated Statistical Analysis Software (SAS®) macros for line of therapy identification are provided to facilitate and standardize the use of real-world databases for oncology research.

PMID:33629590 | DOI:10.2217/fon-2020-1041