Category: Statistics

PLoS One. 2022 Oct 3;17(10):e0271240. doi: 10.1371/journal.pone.0271240. eCollection 2022.

ABSTRACT

In low-dimensional data and within the framework of a classical linear regression model, we intend to compare variable selection methods and investigate the role of shrinkage of regression estimates in a simulation study. Our primary aim is to build descriptive models that capture the data structure parsimoniously, while our secondary aim is to derive a prediction model. Simulation studies are an important tool in statistical methodology research if they are well designed, executed, and reported. However, bias in favor of an “own” preferred method is prevalent in most simulation studies in which a new method is proposed and compared with existing methods. To overcome such bias, neutral comparison studies, which disregard the superiority or inferiority of a particular method, have been proposed. In this paper, we designed a simulation study with key principles of neutral comparison studies in mind, though certain unintentional biases cannot be ruled out. To improve the design and reporting of a simulation study, we followed the recently proposed ADEMP structure, which entails defining the aims (A), data-generating mechanisms (D), estimand/target of analysis (E), methods (M), and performance measures (P). To ensure the reproducibility of results, we published the protocol before conducting the study. In addition, we presented earlier versions of the design to several experts whose feedback influenced certain aspects of the design. We will compare popular penalized regression methods (lasso, adaptive lasso, relaxed lasso, and nonnegative garrote) that combine variable selection and shrinkage with classical variable selection methods (best subset selection and backward elimination) with and without post-estimation shrinkage of parameter estimates.

PMID:36191290 | DOI:10.1371/journal.pone.0271240

Cancer. 2022 Oct 3. doi: 10.1002/cncr.34440. Online ahead of print.

ABSTRACT

Despite high mortality rates from gastric cancer, surgical management remains critical for curative potential. Optimal outcomes of gastric cancer resection depend on a multitude of variables, including the extent of resection, scope of lymphadenectomy, method of reconstruction, and potential for a minimally invasive approach. Laparoscopic gastrectomy, compared with open gastrectomy, has been analyzed in numerous randomized control trials. Generally, those trials demonstrated statistically similar postoperative complication rates, mortality, and oncologic outcomes between the two approaches. Although laparoscopic gastrectomy requires longer operative times, significant improvements in estimated blood loss, postoperative length of stay, and return of bowel function have been noted in patients who undergo laparoscopic gastrectomy. These short-term benefits, along with equivalent oncologic results, have influenced national guidelines in both Eastern and Western countries to recommend laparoscopy, especially for early stage disease. Although robotic gastrectomy has not been as widely validated in effective trials, studies have reported equivalent oncologic outcomes and similar or improved postoperative complication and recovery rates after robotic gastrectomy compared with open gastrectomy. Comparing the two minimally invasive gastrectomy approaches, robotic surgery was associated with improved estimated blood loss, incidence of pancreatic sequela, and lymph node harvests in some studies, whereas laparoscopy resulted in lower operative times and hospital costs. Ultimately, when applying outcomes from the literature to clinical patient care decisions, it is imperative to recognize these studies’ range of inclusion criteria, delineating between patients originating from Eastern or Western countries, the use of neoadjuvant chemotherapy, the volume of surgeon experience, and the extent of gastrectomy, among others.

PMID:36191278 | DOI:10.1002/cncr.34440

Environ Sci Technol. 2022 Oct 3. doi: 10.1021/acs.est.2c02099. Online ahead of print.

ABSTRACT

As the climate warms, wildfire activity is increasing, posing a risk to human health. Studies have reported on particulate matter (PM) in wildfire smoke, yet the chemicals associated with PM have received considerably less attention. Here, we analyzed 13 years (2006-2018) of PM_2.5 chemical composition data from monitors in California on smoke-impacted days. Select chemicals (e.g., aluminum and sulfate) were statistically elevated on smoke-impacted days in over half of the years studied. Other chemicals, mostly trace metals harmful to human health (e.g., copper and lead), were elevated during particular fires only. For instance, in 2018, lead was more than 40 times higher on smoke days on average at the Point Reyes monitoring station, due mostly to the Camp Fire, burning approximately 200 km away. There was an association between these metals and the combustion of anthropogenic material (e.g., the burning of houses and vehicles). Although still currently rare, these infrastructure fires are likely becoming more common and can mobilize trace metals in smoke far downwind, at levels generally unseen except in the most polluted areas of the country. We hope a better understanding of the chemicals in wildfire smoke will assist in the communication and reduction of public health risks.

PMID:36191257 | DOI:10.1021/acs.est.2c02099

Dev Neurorehabil. 2022 Oct 3:1-9. doi: 10.1080/17518423.2022.2131922. Online ahead of print.

ABSTRACT

This study aimed to examine the acute changes in dynamic balance Postural Control experienced by children with Autism Spectrum Disorder (ASD) who undertook a 6-month extracurricular Service-Learning Physical Education (PE) program. The study used a quasi-experimental design with 23 participants divided into an experimental group and a control group. Limits of Stability protocol was used to measure the children’s postural control. The results showed that the experimental group achieved statistically significant improvements. To conclude, this study provides substantial input about how extracurricular PE activities aimed at developing the general motor proficiency of ASD children can improve their dynamic balance.

PMID:36191252 | DOI:10.1080/17518423.2022.2131922

Ultrasound Obstet Gynecol. 2022 Oct 3. doi: 10.1002/uog.26089. Online ahead of print.

ABSTRACT

OBJECTIVE: To develop a model based on factors available at diagnosis of twin-twin transfusion syndrome (TTTS) that predicts chance of dual twin survival following fetoscopic laser photocoagulation (FLPC) using machine learning algorithm.

METHODS: A retrospective analysis of data collected from two university-affiliated tertiary fetal centers between 2012 and 2021. The cohort included monochorionic twin pregnancies complicated by TTTS who underwent FLPC. Data were stratified based on survival rates 30 days after delivery, dual survival cases were compared to the rest. Following random forest, as an ensemble machine-learning algorithm, relative importance value was calculated for each parameter that presented statistically significant difference. Holdout method was applied to check overfitting of the random forest algorithm. A prediction model for having dual twin survival 30 days after delivery was constructed to a graphic nomogram based on the testing set.

RESULTS: The study included 537 women, of them 346 (64.4%) had dual twin survival at 30 days and were compared to 191 (35.6%) that had one or no survivors. Univariate analysis demonstrated no differences in demographic parameters between the groups. At time of diagnosis, the dual survival groups presented lower rates of donor’s estimated fetal weight below 10^th centile for gestational age (56.4% vs. 69.4% p=0.004), intertwin growth discordance above 25% (40.8% vs. 56.5%, p=0.001), and anterior placenta (40.5% vs. 50%, p=0.034). Doppler differences between the groups demonstrated lower rates of elevated pulsatility index (PI) above 95^th centile, measured in the donor’s umbilical artery and ductus venosus, as well as lower rates of decreased PI below 5^th centile, measured in the donor’s middle cerebral artery. Importance value for each of these 6 parameters was calculated allowing the construction of a prediction model with area under ROC curve (AUC=0.916, 95% CI= 0.887-0.946).

CONCLUSIONS: Incorporating six variables: donor’s estimated fetal weight below 10^th centile, intertwin growth discordance above 25%, anterior placenta, pulsatility index in the umbilical artery, ductus venosus and middle cerebral artery, obtained at time of diagnosis of TTTS into a predictive model for dual twin survival following FLPC has been developed. This clinically applicable tool may allow improved treatment plans and patient counseling. This article is protected by copyright. All rights reserved.

PMID:36191157 | DOI:10.1002/uog.26089

IEEE Trans Neural Syst Rehabil Eng. 2022 Oct 3;PP. doi: 10.1109/TNSRE.2022.3211450. Online ahead of print.

ABSTRACT

The side effects and complications of traditional treatments for treating pathological tremor have led to a growing research interest in wearable tremor suppression devices (WTSDs) as an alternative approach. Similar to how the human brain coordinates the function of the human system, a tremor estimator determines how a WTSD functions. Although many tremor estimation algorithms have been developed and validated, whether they can be implemented on a cost-effective embedded system has not been studied; furthermore, their effectiveness on tremor signals with multiple harmonics has not been investigated. Therefore, in this study, four tremor estimators were implemented, evaluated, and compared: Weighted-frequency Fourier Linear Combiner (WFLC), WFLC-based Kalman Filter (WFLC-KF), Band-limited Multiple FLC, and enhanced High-order WFLC-KF (eHWFLC-KF). This study aimed to evaluate the performance of each algorithm on a bench-top tremor suppression system with 18 recorded tremor motion datasets; and compare the performance of each estimator. The experimental evaluation showed that the eHWFLC-KF-based WTSD achieved the best performance when suppressing tremor with an average of 89.3% reduction in tremor power, and an average error when tracking voluntary motion of 6.6°/s. Statistical analysis indicated that the eHWFLC-KF-based WTSD is able to reduce the power of tremor better than the WFLC and WFLC-KF, and the BMFLC-based WTSD is better than the WFLC. The performance when tracking voluntary motion is similar among all systems. This study has proven the feasibility of implementing various tremor estimators in a cost-effective embedded system, and provided a real-time performance assessment of four tremor estimators.

PMID:36191110 | DOI:10.1109/TNSRE.2022.3211450

IEEE Trans Ultrason Ferroelectr Freq Control. 2022 Oct 3;PP. doi: 10.1109/TUFFC.2022.3211484. Online ahead of print.

ABSTRACT

Biaxial transducers are an emerging technology that can steer generated ultrasound waves using a single piezoceramic component. Simulations have also shown that biaxial transducers can passively estimate the direction of arrival of sound waves when operating in receive mode. This research seeks to experimentally verify biaxial directivity estimates and establish directivity as an independent parameter detected by biaxial transducers. Three cuboid (3.84 mm x 3.84 mm x 5.92 mm) biaxial piezoceramics with two pairs of orthogonal electrodes (one pair applied laterally and one pair applied in the polling direction) were manufactured and characterized. Each transducer was placed in a water tank where an independent hemispherical source was attached to a moveable arm and operated at 250 kHz. Terminal voltages were recorded for eighty-one source positions in a plane parallel to the transducer’s front face and at a depth of approximately 9 cm. Collection was repeated three times per transducer to ensure reproducibility. In-silico results were compared with the experimental results. Two derived metrics were then calculated using both the forward and lateral terminal voltages: the phase difference and amplitude ratio. Biaxial transducers demonstrate an ability to estimate the direction of arrival of incident sound waves, independently of any time-of-flight information. The phase difference and amplitude ratio complement each other to provide statistically significant and repeatable estimates over a range of 48 degrees (from -24 degrees to +24 degrees). These results can be used to augment a variety of medical, geophysical, and industrial passive ultrasound imaging techniques.

PMID:36191096 | DOI:10.1109/TUFFC.2022.3211484

Clin Spine Surg. 2022 Aug 3. doi: 10.1097/BSD.0000000000001365. Online ahead of print.

ABSTRACT

STUDY DESIGN: Prospective randomized Food and Drug Administration investigational device exemption clinical trial.

OBJECTIVE: The purpose of the present study is to report the 1-year clinical and radiographic outcomes and safety profile of patients who underwent lumbar facet arthroplasty through implantation of the Total Posterior Spine System (TOPS) device.

SUMMARY OF BACKGROUND DATA: Lumbar facet arthroplasty is one proposed method of dynamic stabilization to treat grade-1 spondylolisthesis with stenosis; however, there are currently no Food and Drug Administration-approved devices for facet arthroplasty.

METHODS: Standard demographic information was collected for each patient. Radiographic parameters and patient-reported outcome measures were assessed preoperatively and at regular postoperative intervals. Complication and reoperation data were also collected for each patient.

RESULTS: At the time of this study, 153 patients had undergone implantation of the TOPS device. The mean surgical time was 187.8 minutes and the mean estimated blood loss was 205.7cc. The mean length of hospital stay was 3.0 days. Mean Oswestry Disability Index, Visual Analog Score leg and back, and Zurich Claudication Questionnaire scores improved significantly at all postoperative time points (P>0.001). There were no clinically significant changes in radiographic parameters, and all operative segments remained mobile at 1-year follow-up. Postoperative complications occurred in 11 patients out of the 153 patients (7.2%) who underwent implantation of the TOPS device. Nine patients (5.9%) underwent a total of 13 reoperations, 1 (0.6%) of which was for device-related failure owing to bilateral L5 pedicle screw loosening.

CONCLUSIONS: Lumbar facet arthroplasty with the TOPS device demonstrated a statistically significant improvement in all patient-reported outcome measures and the ability to maintain motion at the index level while limiting sagittal translation with a low complication rate.

PMID:36191093 | DOI:10.1097/BSD.0000000000001365

Hum Reprod Update. 2022 Oct 3:dmac034. doi: 10.1093/humupd/dmac034. Online ahead of print.

ABSTRACT

BACKGROUND: Depression and anxiety are highly prevalent among individuals struggling with infertility. Thus, numerous psychological interventions have been adapted to infertility, with the aim of relieving distress as well as increasing pregnancy rates.

OBJECTIVE AND RATIONALE: This systematic review and meta-analysis aimed to identify all randomized controlled trials (RCTs) evaluating the effect of psychological interventions on infertility-related distress and pregnancy rates among individuals and/or couples with infertility and to analyse their overall effect. It also sought to examine potential treatment moderators, including intervention length, format and therapeutic approach.

SEARCH METHODS: An electronic search of 11 databases, including MEDLINE, EMBASE, PsycINFO and Cochrane Central Register of Controlled Trials, was performed for studies published until January 2022. The inclusion criteria were RCTs conducted on humans and published in English. Psychological outcomes of interest included anxiety, depression, infertility-related distress, wellbeing and marital satisfaction. The Cochrane Risk of Bias tool was used to assess study quality, and the Grading of Recommendations Assessment, Development and Evaluation was used to assess the overall quality of the research evidence.

OUTCOMES: There were 58 RCTs in total, including 54 which included psychological outcomes and 21 which assessed pregnancy rates. Studies originated from all regions of the world, but nearly half of the studies were from the Middle East. Although a beneficial effect on combined psychological outcomes was found (Hedge’s g = 0.82, P < 0.0001), it was moderated by region (P < 0.00001) such that studies from the Middle East exhibited large effects (g = 1.40, P < 0.0001), while the effects were small among studies conducted elsewhere (g = 0.23, P < 0.0001). Statistically adjusting for study region in a meta-regression, neither intervention length, therapeutic approach, therapy format, nor participant gender (P > 0.05) moderated the effect of treatment. A beneficial treatment effect on pregnancy (RR (95% CI) = 1.25 (1.07-1.47), P = 0.005) was not moderated by region, treatment length, approach or format (P > 0.05). Largely due to the lack of high quality RCTs, the quality of the available evidence was rated as low to moderate.

WIDER IMPLICATIONS: This is the first meta-analysis of RCTs testing the effect of psychological interventions on infertility-related distress and pregnancy rates. These findings suggest that in most regions of the world, psychological interventions are associated with small reductions in distress and modest effects on conception, suggesting the need for more effective interventions. These findings must be considered in light of the fact that the majority of the included RCTs were deemed to be at high risk of bias. Rigorously conducted trials are needed.

PMID:36191078 | DOI:10.1093/humupd/dmac034

J Am Assoc Nurse Pract. 2022 Oct 1;34(10):1174-1180. doi: 10.1097/JXX.0000000000000774.

ABSTRACT

BACKGROUND: Goals of care conversations (GoCCs) are essential discussions, for those with chronic diseases, to identify a health care surrogate, initiate and review advance directives, and refer for palliative care. Prognosis with pulmonary hypertension (PH) related to heart failure (HF) remains challenging due to variation in trajectory of disease progression. The Gagne Combined Comorbidity score, an electronic prognostication score (E-Gagne), can be used to identify patients with high (>10%) 1-year mortality.

LOCAL PROBLEM: Implementation of E-Gagne tool to identify HF patients with high 1-year mortality risk and trigger GoCCs.

METHODS: Plan-Do-Study-Act cycles were used throughout nine-week pre- and postintervention in an outpatient setting. Descriptive statistics and Chi-square analysis were used to compare GoCCs pre and post intervention.

INTERVENTION: Using the E-Gagne tool, PH patients with high mortality risk were identified, within 1 week of their scheduled appointments. GoCCs education was provided to all stakeholders. Medical records were reviewed for four aspects of GoCCs: presence and review of advanced directive, documented health care surrogates, and referral for palliative care.

RESULTS: Documentation of GoCCs was greater postintervention compared with preintervention (0%, n = 0/47 and 88%, n = 35/40 respectively, p < .001). Documentation of each of the four aspects of GoCCs was variable with the greatest improvement in documentation of health care surrogate and review of advance directives. There were no referrals for palliative care (0%, n = 0/47 and 0%, n = 0/40).

CONCLUSION: Implementation of the E-Gagne tool, an electronic prognostication tool, identified high-risk PH HF patients and was effective in increasing documentation of GoCCs.

PMID:36191076 | DOI:10.1097/JXX.0000000000000774