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Nevin Manimala Statistics

A practical guide to random-effects Bayesian meta-analyses with application to the psychological trauma and suicide literature

Psychol Trauma. 2022 Jul 21. doi: 10.1037/tra0001316. Online ahead of print.

ABSTRACT

OBJECTIVE: Bayesian meta-analyses offer several advantages over traditional approaches, including improved accuracy when using a small number of studies and enhanced estimation of heterogeneity. However, psychological trauma research has yet to see widespread adoption of these statistical methods, potentially due to researchers’ unfamiliarity with the processes involved. The purpose of this article is to provide a practical tutorial for conducting random-effects Bayesian meta-analyses.

METHOD: Explanations and recommendations are provided for completing the primary steps of a Bayesian meta-analysis, ranging from model specification to interpretation of results. Furthermore, an illustrative example is used to demonstrate the application of each step. In the example, results are synthesized from six studies included in a previously published systematic review (Holliday et al., 2020), with a combined sample size of 21,244,109, examining the association between posttraumatic stress disorder and risk of suicide in veterans and military personnel.

RESULTS: The posterior distributions for each model estimate, such as the pooled effect size and the heterogeneity parameter, are discussed and interpreted with regard to the probability of increased suicide risk.

CONCLUSIONS: Our hope is that this tutorial, along with the provided data and code, facilitate the use of Bayesian meta-analyses in the study of psychological trauma. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

PMID:35862085 | DOI:10.1037/tra0001316

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Nevin Manimala Statistics

Machine Learning-Based Prediction of Masked Hypertension Among Children With Chronic Kidney Disease

Hypertension. 2022 Jul 7:101161YPERTENSIONAHA12118794. doi: 10.1161/HYPERTENSIONAHA.121.18794. Online ahead of print.

ABSTRACT

BACKGROUND: Ambulatory blood pressure monitoring (ABPM) is routinely performed in children with chronic kidney disease to identify masked hypertension, a risk factor for accelerated chronic kidney disease progression. However, ABPM is burdensome, and developing an accurate prediction of masked hypertension may allow using ABPM selectively rather than routinely.

METHODS: To create a prediction model for masked hypertension using clinic blood pressure (BP) and other clinical characteristics, we analyzed 809 ABPM studies with nonhypertensive clinic BP among the participants of the Chronic Kidney Disease in Children study.

RESULTS: Masked hypertension was identified in 170 (21.0%) observations. We created prediction models for masked hypertension via gradient boosting, random forests, and logistic regression using 109 candidate predictors and evaluated its performance using bootstrap validation. The models showed C statistics from 0.660 (95% CI, 0.595-0.707) to 0.732 (95% CI, 0.695-0.786) and Brier scores from 0.148 (95% CI, 0.141-0.154) to 0.167 (95% CI, 0.152-0.183). Using the possible thresholds identified from this model, we stratified the dataset by clinic systolic/diastolic BP percentiles. The prevalence of masked hypertension was the lowest (4.8%) when clinic systolic/diastolic BP were both <20th percentile, and relatively low (9.0%) with clinic systolic BP<20th and diastolic BP<80th percentiles. Above these thresholds, the prevalence was higher with no discernable pattern.

CONCLUSIONS: ABPM could be used selectively in those with low clinic BP, for example, systolic BP<20th and diastolic BP<80th percentiles, although careful assessment is warranted as masked hypertension was not completely absent even in this subgroup. Above these clinic BP levels, routine ABPM remains recommended.

PMID:35862083 | DOI:10.1161/HYPERTENSIONAHA.121.18794

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Nevin Manimala Statistics

Correlates of vaping among adolescents in Canada

Health Rep. 2022 Jul 20;33(7):24-35. doi: 10.25318/82-003-x202200700003-eng.

ABSTRACT

BACKGROUND: Vaping is more prevalent among younger than older Canadians. While vaping is less harmful than combustible tobacco, it is not without health risk.

DATA AND METHODS: Data from the 2019 Canadian Health Survey on Children and Youth were used to estimate vaping prevalence. Logistic regression models assessed the association of sociodemographic, youth, parenting and peer factors with vaping. The 2020 Canadian Community Health Survey identified adolescents who reported vaping before tobacco smoking. Data from the 2019 Canadian Tobacco and Nicotine Survey were used to examine vaping of e-liquids containing nicotine and flavours.

RESULTS: Vaping rates for 15- to 17-year-olds were nearly four times (21.3%) higher than those of 12- to 14-year-olds (5.4%). Two-thirds (66.1%) of 12- to 17-year-olds who had used both tobacco and e-cigarettes reported trying e-cigarettes first. E-liquids containing nicotine were used by 89.3% of 15- to 19-year-olds who reported vaping in the past 30 days; comparable with older adults. For both younger and older adolescents, having friends who engaged in negative behaviours, having been employed, and having consumed alcohol increased the odds. For 12- to 14-year-olds, attention deficit hyperactivity disorder was a risk factor, whereas having parents who usually knew who they were with and higher relatedness scores were protective. Among older adolescents, being male, being Canadian-born, having lower grades, and using tobacco or cannabis increased the odds of vaping.

INTERPRETATION: An adolescent’s risk of vaping was most strongly correlated with other substance use, although other youth, parenting and peer characteristics also mattered. Because most of the data presented were collected before the COVID-19 pandemic and new vaping regulations, ongoing monitoring remains important.

PMID:35862070 | DOI:10.25318/82-003-x202200700003-eng

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Nevin Manimala Statistics

Multi-scale modelling of nanoparticle delivery and heat transport in vascularised tumours

Math Med Biol. 2022 Jul 21:dqac009. doi: 10.1093/imammb/dqac009. Online ahead of print.

ABSTRACT

We focus on modelling of cancer hyperthermia driven by the application of the magnetic field to iron oxide nanoparticles. We assume that the particles are interacting with the tumour environment by extravasating from the vessels into the interstitial space. We start from Darcy’s and Stokes’ problems in the interstitial and fluid vessels compartments. Advection-diffusion of nanoparticles takes place in both compartments (as well as uptake in the tumour interstitium), and a heat source proportional to the concentration of nanoparticles drives heat diffusion and convection in the system. The system under consideration is intrinsically multi-scale. The distance between adjacent vessels (the micro-scale) is much smaller than the average tumour size (the macro-scale). We then apply the asymptotic homogenisation technique to retain the influence of the micro-structure on the tissue scale distribution of heat and particles. We derive a new system of homogenised partial differential equations (PDEs) describing blood transport, delivery of nanoparticles and heat transport. The new model comprises a double Darcy’s law, coupled with two double advection-diffusion-reaction systems of PDEs describing fluid, particles and heat transport and mass, drug and heat exchange. The role of the micro-structure is encoded in the coefficients of the model, which are to be computed solving appropriate periodic problems. We show that the heat distribution is impaired by increasing vessels’ tortuosity and that regularization of the micro-vessels can produce a significant increase (1-2 degrees) in the maximum temperature. We quantify the impact of modifying the properties of the magnetic field depending on the vessels’ tortuosity.

PMID:35862063 | DOI:10.1093/imammb/dqac009

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Nevin Manimala Statistics

Comparison of Outcomes of Ischemic Stroke Initially Imaged With Cranial Computed Tomography Alone vs Computed Tomography Plus Magnetic Resonance Imaging

JAMA Netw Open. 2022 Jul 1;5(7):e2219416. doi: 10.1001/jamanetworkopen.2022.19416.

ABSTRACT

IMPORTANCE: Patients with acute ischemic stroke often undergo magnetic resonance imaging (MRI) in addition to computed tomography (CT), but its association with clinical outcomes is uncertain.

OBJECTIVE: To assess whether clinical outcomes of patients with acute ischemic stroke with initial CT alone were noninferior to those with additional MRI.

DESIGN, SETTING, AND PARTICIPANTS: A retrospective observational propensity score-matched cohort study of clinical outcomes at discharge and 1 year for patients hospitalized with acute ischemic stroke was conducted at an academic medical center between January 2015 and December 2017. Data collection from an electronic medical record system performed from May 2020 through January 2022 was not completely blinded. Noninferiority margins were based on the designs of previous randomized clinical trials of ischemic stroke treatments. Statistical analysis was performed in January 2022. Participants were adults hospitalized with acute ischemic stroke with admission diagnosis based on CT. Exclusion criteria were primarily missing data. From 508 eligible patients, all 123 cases with additional MRI were propensity-score matched to 123 controls without.

EXPOSURE: MRI after initial diagnosis.

MAIN OUTCOMES AND MEASURES: Death or dependence at hospital discharge (modified Rankin Scale score of 3-6) and stroke or death occurring in survivors within 1 year after discharge.

RESULTS: Among 246 participants, the median age was 68 years (IQR, 58-78.8 years) and 131 (53.0%) were men. Death or dependence at discharge occurred more often in patients with additional MRI (59 of 123 [48.0%]) than in those with CT alone (52 of 123 [42.3%]; absolute difference, 5.7%; 95% CI, -6.7% to 18.1%), meeting the -7.50% criterion for noninferiority. Stroke or death within 1 year after discharge determined for 225 of 235 (96%) survivors occurred more often in patients with additional MRI (22 of 113 [19.5%]) than in those with CT alone (14 of 112 [12.5%]; relative risk, 1.14; 95% CI, 0.86-1.50), meeting the 0.725 relative risk criterion for noninferiority.

CONCLUSIONS AND RELEVANCE: This propensity score-matched cohort study of patients hospitalized with acute ischemic stroke found that a diagnostic imaging strategy of initial CT alone was noninferior to initial CT plus additional MRI with regard to clinical outcomes at discharge and at 1 year. Further research is needed to determine which patients hospitalized with acute ischemic stroke benefit from MRI.

PMID:35862046 | DOI:10.1001/jamanetworkopen.2022.19416

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Nevin Manimala Statistics

Estimating Weekly National Opioid Overdose Deaths in Near Real Time Using Multiple Proxy Data Sources

JAMA Netw Open. 2022 Jul 1;5(7):e2223033. doi: 10.1001/jamanetworkopen.2022.23033.

ABSTRACT

IMPORTANCE: Opioid overdose is a leading public health problem in the United States; however, national data on overdose deaths are delayed by several months or more.

OBJECTIVES: To build and validate a statistical model for estimating national opioid overdose deaths in near real time.

DESIGN, SETTING, AND PARTICIPANTS: In this cross-sectional study, signals from 5 overdose-related, proxy data sources encompassing health, law enforcement, and online data from 2014 to 2019 in the US were combined using a LASSO (least absolute shrinkage and selection operator) regression model, and weekly predictions of opioid overdose deaths were made for 2018 and 2019 to validate model performance. Results were also compared with those from a baseline SARIMA (seasonal autoregressive integrated moving average) model, one of the most used approaches to forecasting injury mortality.

EXPOSURES: Time series data from 2014 to 2019 on emergency department visits for opioid overdose from the National Syndromic Surveillance Program, data on the volume of heroin and synthetic opioids circulating in illicit markets via the National Forensic Laboratory Information System, data on the search volume for heroin and synthetic opioids on Google, and data on post volume on heroin and synthetic opioids on Twitter and Reddit were used to train and validate prediction models of opioid overdose deaths.

MAIN OUTCOMES AND MEASURES: Model-based predictions of weekly opioid overdose deaths in the United States were made for 2018 and 2019 and compared with actual observed opioid overdose deaths from the National Vital Statistics System.

RESULTS: Statistical models using the 5 real-time proxy data sources estimated the national opioid overdose death rate for 2018 and 2019 with an error of 1.01% and -1.05%, respectively. When considering the accuracy of weekly predictions, the machine learning-based approach possessed a mean error in its weekly estimates (root mean squared error) of 60.3 overdose deaths for 2018 (compared with 310.2 overdose deaths for the SARIMA model) and 67.2 overdose deaths for 2019 (compared with 83.3 overdose deaths for the SARIMA model).

CONCLUSIONS AND RELEVANCE: Results of this serial cross-sectional study suggest that proxy administrative data sources can be used to estimate national opioid overdose mortality trends to provide a more timely understanding of this public health problem.

PMID:35862045 | DOI:10.1001/jamanetworkopen.2022.23033

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Nevin Manimala Statistics

Incidence, Associated Risk Factors, and Outcomes of Postoperative Arrhythmia After Upper Gastrointestinal Surgery

JAMA Netw Open. 2022 Jul 1;5(7):e2223225. doi: 10.1001/jamanetworkopen.2022.23225.

ABSTRACT

IMPORTANCE: New-onset postoperative arrhythmia, which most often presents as postoperative atrial fibrillation (AF), is a frequent complication in patients undergoing visceral surgery of the upper gastrointestinal tract. Its relevance for patients’ outcomes is unknown.

OBJECTIVE: To assess the incidence of arrhythmia after upper gastrointestinal surgery, its risk factors, and its short- and long-term implications for patient outcomes.

DESIGN, SETTING, AND PARTICIPANTS: This cohort study included 1210 patients who underwent surgery of the upper gastrointestinal tract (esophagus, stomach, or pancreas) at the University Medical Center Göttingen in Germany between January 2012 and December 2018. Follow-up was performed between February and May 2020. Patients were excluded if they had a preexisting cardiac arrhythmia or pacemaker.

MAIN OUTCOMES AND MEASURES: The incidence of atrial fibrillation (AF) was recorded in most cases of postoperative arrhythmia; therefore, the analysis focused on postoperative AF. A multivariable logistic regression model was used to assess associations between surgical complications and postoperative AF occurrence, with odds ratios and 95% CIs reported.

RESULTS: A total of 1210 patients (median [IQR] age, 62 [19-90] years; 704 [58.2%] men) were enrolled in this study. Postoperative arrhythmia was recorded in 100 patients (8.3%). Among the different procedures, esophagectomy was associated with the highest incidence of postoperative AF (45.5% in complex esophageal resections and 17.1% in elective thoracoabdominal esophagectomies). The incidence of postoperative AF was associated with prolonged length of stay in the intensive care unit (23.4 days for patients with postoperative AF vs 5.9 days for those without; P < .001). Four factors were associated with the occurrence of postoperative AF: patients’ age (OR, 1.06; 95% CI, 1.03-1.08; P < .001), intraoperative surgical complications (OR, 2.47; 95% CI, 1.29-4.74; P = .006), infections (OR, 2.23; 95% CI, 1.31-3.80; P = .003), and organ failure (OR, 4.01; 95% CI, 2.31-6.99; P < .001). In the multivariable analysis, postoperative AF (OR, 7.08; 95% CI, 2.75-18.23; P < .001) and sepsis (OR, 10.98; 95% CI, 3.91-30.81; P < .001) were associated with in-hospital mortality. At a median 19-month follow-up, 20 of 74 patients (27.0%) with postoperative AF developed recurring episodes of arrhythmia after discharge.

CONCLUSIONS AND RELEVANCE: This cohort study found that the postoperative AF was associated with an increased length of stay in the intensive care unit and in-hospital mortality in patients after upper gastrointestinal tract surgery. In addition, postoperative AF was associated with development of permanent or paroxysmal arrhythmia after discharge.

PMID:35862044 | DOI:10.1001/jamanetworkopen.2022.23225

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Nevin Manimala Statistics

“COVID-Somnia” in healthcare workers during the pandemic

Hosp Pract (1995). 2022 Jul 21. doi: 10.1080/21548331.2022.2102777. Online ahead of print.

ABSTRACT

OBJECTIVES: Sleep disorders associated with COVID-19 pandemic are termed as “COVID-somnia”. In this study, we sought to assess the prevalence of COVID-somnia in healthcare workers, establish the factors that trigger this condition, and to investigate its relationship with anxiety and depression symptoms.

METHODS: This cross-sectional study was conducted between April 2021 and June 2021, and it included healthcare workers who served during the pandemic. Participants’ demographic data, Beck Depression and Anxiety Inventories, Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and Insomnia Severity Index (ISI) were used, and the results were statistically analyzed. Multiple analyses of factors affecting ESS and ISI scores were evaluated using binary logistic regression model and PSQI score were analyzed using a multiple linear regression model.

RESULTS: A total of 1,111 healthcare workers who served during the pandemic voluntarily enrolled to the study. The mean age was 37.3 ± 8.48 years, and 63.5% were females. Our study showed that the healthcare workers, evaluated with the PSQI, experienced a deterioration of sleep quality. Primary factors affecting this are working on the front line, the presence of chronic diseases, depression, and anxiety. Regression analyses identified depression and anxiety as the common factors affecting ESS, ISI, and PSQI scores.

CONCLUSION: Raising awareness regarding COVID-somnia among healthcare workers, who play a leading role in curbing the pandemic, would reduce sleep disturbances, depression, and anxiety. It would also contribute to the planning and implementation of preventive and therapeutic mental health programs with a multidisciplinary approach.

PMID:35861139 | DOI:10.1080/21548331.2022.2102777

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Nevin Manimala Statistics

Impact of radiographic field-of-view volume on alignment accuracy during virtual implant planning: A noninterventional retrospective pilot study

Clin Oral Implants Res. 2022 Jul 21. doi: 10.1111/clr.13983. Online ahead of print.

ABSTRACT

OBJECTIVE: To evaluate the impact of reducing the radiographic field-of-view (FOV) on the trueness and precision of the alignment between cone beam computed tomography (CBCT) and intraoral scanning data for implant planning.

MATERIALS AND METHODS: Fifteen participants presenting with one of three clinical scenarios: single tooth loss (ST, n=5), multiple missing teeth (MT, n=5), and presence of radiographic artifacts (AR, n=5) were included. CBCT volumes covering the full arch (FA) were reduced to the quadrant (Q) or the adjacent tooth/teeth (A). Two operators, an expert (exp) in virtual implant planning and an inexperienced clinician, performed multiple superimpositions, with FA-exp serving as a reference. The deviations were calculated at the implant apex and shoulder levels. Thereafter, linear mixed models were adapted to investigate the influence of FOV on discrepancies.

RESULTS: Evaluation of trueness compared to FA-exp resulted in the largest mean (AR-A: 0.10 ± 0.33 mm) and single maximum discrepancy (AR-Q: 1.44 mm) in the presence of artifacts. Furthermore, for the ST group, the largest mean error (-0.06 ± 0.2 mm, shoulder) was calculated with the FA-FOV, while for MT, with the intermediate volume (-0.07 ± 0.24 mm, Q). In terms of precision, the mean SD intervals were ≤0.25 mm (A-exp). Precision was influenced by FOV volume (FA<Q<A) but not by operator expertise.

CONCLUSIONS: For single posterior missing teeth, an extended FOV does not improve registration accuracy. However, in the presence of artifacts or multiple missing posterior teeth, caution is recommended when reducing FOV.

PMID:35861131 | DOI:10.1111/clr.13983

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In vitro scanning accuracy using different aids for multiple implants in the edentulous arch

Clin Oral Implants Res. 2022 Jul 21. doi: 10.1111/clr.13982. Online ahead of print.

ABSTRACT

OBJECTIVES: Optical impressions of implants in the edentulous arch are challenged by the absence of distinct surface morphology between multiple implant scan bodies. The purpose of this in vitro study was to evaluate a newly developed scan aid in various designs and colors to improve the accuracy of multi-implant scans.

MATERIAL AND METHODS: A universal scan aid in three different designs (circular, square, irregular) and three different materials (colors: beige, gray, white) was applied to the implant scan bodies of a master model of 6 implants in an edentulous maxilla. Ten scans using an intra-oral scanner of each scan aid were acquired. Reference scanning was performed using a desktop optical scanner. Alignment of scans was performed at the first scan body in a three-dimensional modeling and inspection software and deviations for trueness and precision were calculated using the signed nearest neighbor method and then statistically analyzed (α=.05).

RESULTS: Overall, the beige irregular scan aid had the highest trueness and showed significant differences compared to unsplinted scans. The precision showed more heterogenous results and decreased when using the scan aid. Ease of use was observed with the irregular gray scan aid due to its increased elongation at break.

CONCLUSIONS: The evaluated scan aid led to improved trueness when compared to unsplinted scans. Even though the irregular design in beige color showed highest trueness, the poor fracture strength of the tested material requires further improvement.

PMID:35861128 | DOI:10.1111/clr.13982