Category: Statistics

IEEE Trans Ultrason Ferroelectr Freq Control. 2021 Dec 22;PP. doi: 10.1109/TUFFC.2021.3137425. Online ahead of print.

ABSTRACT

Time series measurements with data gaps (dead times) prevent accurate computations of frequency stability variances such as the Allan variance (AVAR) and its square-root the Allan deviation (ADEV). To extract frequency distributions, time series data must be sequentially ordered and equally spaced. Data gaps, particularly large ones, make ADEV estimates unreliable. Gap imputation by interpolation, zero-padding, or adjoining live segments, all fail in various ways. We have devised an algorithm that fills gaps by imputing an extension of preceding live data and explain its advantages. To demonstrate the effectiveness of the algorithm, we have implemented it on 513-length original datasets and have removed 30% (150 values). The resulting data is consistent with the original in all three major criteria: the noise characteristic, the distribution, and the ADEV levels and slopes. Of special importance is that all ADEV measurements on the imputed data set lie within 90% confidence of the statistic for the original dataset.

PMID:34936554 | DOI:10.1109/TUFFC.2021.3137425

Traffic Inj Prev. 2021 Dec 22:1-6. doi: 10.1080/15389588.2021.2004311. Online ahead of print.

ABSTRACT

OBJECTIVE: Motorcycles, moped scooters and bicycles are commonly involved in traffic accidents and riders often suffer significant morbidity and mortality. The aim of this study is to compare and categorize the different injury patterns and fractures suffered by riders of each vehicle type after a traffic accident.

METHODS: Data from a level 1 trauma center in Las Vegas, Nevada were analyzed. Traffic accident victims riding a motorcycle, moped, or bicycle from 2013 to 2017 were included. Injury location and fracture location were assigned to six and sixteen categorical locations, respectively. Descriptive statistics, including frequency counts for categorical data and mean for continuous data, were calculated for the full sample and for each of the vehicle types. Logistic regression was performed on race, categorized age, vehicle type and helmet use to calculate adjusted odds ratios for injury type between the three groups.

RESULTS: Of the 2115 patients, 1372 were motorcyclists, 356 were moped scooter riders and 387 were bicyclists. Overall the vast majority of injuries reported were of the extremities or pelvic girdle (62.2%), and this was true regardless of vehicle type. Head and neck injuries were significantly more common in bicyclists (39.5%) and moped riders (34.6%), than in motorcyclists (22.7%). Helmet use was substantially lower in the moped (34%) and bicycle (20%) groups compared to the motorcycle group (85%). The most common fractures regardless of vehicle type were of the skull/face, rib, vertebral, and tibia/fibula with slight variations between vehicle groups.

CONCLUSION: Similarities were seen in the most common fracture and injury patterns between the three groups. Head and neck injuries were much more common in moped and bicycle riders compared to motorcyclists. This is most likely due to the significantly higher percentage of motorcycle riders who wore a helmet. Counseling regarding helmet and protective equipment use, especially among moped and bicycle riders is essential to reduce head injuries.

PMID:34936538 | DOI:10.1080/15389588.2021.2004311

Clin Exp Rheumatol. 2021 Dec 22. Online ahead of print.

ABSTRACT

OBJECTIVES: Systemic lupus erythematosus (SLE) has been associated with insulin resistance and beta-cell dysfunction. Apolipoprotein C3 (ApoC3) is a component of very low-density lipoproteins. Since ApoC3 has been linked to beta-cell impairment in the general population, in this study we aimed to discover if this lipoprotein is related to glucose homeostasis disturbance in patients with SLE.

METHODS: One hundred and forty non diabetic patients with SLE who had a glycaemia lower than 110 mg/dl were recruited. Insulin, C-peptide, and ApoC3 were assessed. Insulin resistance and beta-cell function were calculated using the Homeostasis Model Assessment (HOMA2) indices. A multivariable regression analysis was performed to study the relationship of ApoC3 to those molecules and indices adjusting for classical factors associated with insulin resistance that included glucocorticoids.

RESULTS: In the multivariable regression analysis that included prednisone intake, a significant relation of ApoC3 to C-peptide was found (beta coef. 0.27 [95%CI 0.03-0.51) ng/ml, p=0.030). Similarly, ApoCa3 was associated with higher degree of beta-cell dysfunction (HOMA2-%B) although in this case statistical significance was not achieved (beta coef. 8 [95%CI-1-18], p=0.086). This relationship was not found with serum insulin levels or IR indices. Furthermore, in the univariable analysis, but not after multivariable adjustment, the disease damage score was found to significantly mediate the effect of ApoC3 on circulating C-peptide. and HOMA2-%B.

CONCLUSIONS: Beta-cell dysfunction and ApoC3 are linked in patients with SLE.

PMID:34936546

Disabil Rehabil Assist Technol. 2021 Dec 22:1-10. doi: 10.1080/17483107.2021.2017030. Online ahead of print.

ABSTRACT

PURPOSE: Despite the benefits of wheelchair-mounted robotic arms (WMRAs), occupational therapists are not yet widely involved in the recommendation or implementation of these assistive devices. The purpose of this study was to investigate and compare the current practices and perspectives of occupational therapists who had and had not recommended a WMRA on the recommendation, training, and implementation of WMRAs.

METHODS: This was a descriptive cross-sectional study. An online survey was sent to Canadian, European, and American occupational therapists who had or had not worked with WMRAs. Respondents were asked close-ended questions about their experience, role, barriers, motivations, and future needs regarding WMRAs. We compared results between respondents who had and had not recommended WMRAs using descriptive statistics.

RESULTS: Ninety-three North American and European occupational therapists completed the survey. Of those, 29 (31.2%) had recommended a WMRA, mostly the JACO robotic arm (n = 26, 89.7%) in rehabilitation centres (n = 18, 62.1%). Their perspectives on their role and barriers related to WMRAs were similar to those who had never recommended a WMRA. All respondents recognised the relevance of occupational therapists’ contribution, and most reported interest in WMRAs (n = 76, 81.7%). However, many barriers emerged, mainly related to limited funding (n = 49, 76.6%), lack of training and knowledge (n = 38, 59.4%), and resource constraints (n = 37, 54.4%). Future needs identified matched these barriers.

CONCLUSION: This survey provides novel insight into occupational therapists’ perspectives on WMRAs. It highlights that health professionals need to have easier access to funding, formal training, and resources to support their involvement with WMRAs.Implications for rehabilitationMost occupational therapists are interested in working with WMRAs, considering the potential of these devices to support individuals with upper extremity impairments in their daily activities. They also recognise their unique contribution to the assessment, recommendation, and implementation process among multidisciplinary teams.WMRA recommendation is relevant in various clinical settings and with a wide range of client populations. Nevertheless, it appears that occupational therapists working with adults, in rehabilitation centres or specialised clinics, may have more opportunities to get involved in this process and to attend formal training on this technology, as compared to other settings.Many barriers remain, impeding occupational therapists’ role in the recommendation and implementation of WMRAs. Addressing these barriers may increase the number of devices that are successfully adopted and utilised by individuals with upper extremity impairments. In particular, future research and health policies should focus on access to sufficient funding, formal training, and resources for occupational therapists relative to their role in recommending and implementing WMRAs.

PMID:34936533 | DOI:10.1080/17483107.2021.2017030

Nephrol Nurs J. 2021 Nov-Dec;48(6):527-569.

ABSTRACT

Change in fatigue within a hemodialysis (HD) session has not been established previously. A total of 55 cognitively intact adults on HD were included; individuals with mobility/hemodynamic issues were excluded. Measures included the Piper Fatigue Scale-12 (PFS-12), 6-Minute Walk Test (6MWT), demographic and clinical. Descriptive statistics, ANOVA, and stepwise regression were used. Mean age was 57 years. Mean change in PFS-12 was -4.56 ± 27.85. Mean change in walk distance was -16.26 ± 43.87 meters (p = 0.03). The change in the PFS-12 accounted for 47% quadratic trend in the change in 6MWD (p < 0.001). Both fatigue measures (PFS-12 and 6MWT) can be useful for examining changes in fatigue levels within an HD session. Our findings speak to the convergent validity of these two measures of fatigue.

PMID:34935330

Nephrol Nurs J. 2021 Nov-Dec;48(6):537-546.

ABSTRACT

Comprehensive pre-dialysis discussions between providers and older adults over age 75 years are needed but often lacking. The aim of this study was to develop an instrument to assess behavioral determinants of nephrology provider use of comprehensive pre-dialysis discussions with older adults. Study design consisted of cross-sectional development of the instrument and preliminary psychometric evaluation. Items were based on an integrated literature review, expert clinician input, and the Theory of Planned Behavior. Nephrologists, nurse practitioners, and physician assistants completed the instrument (n = 71). Baseline demographic data, exploratory factor analysis, and Cronbach’s alpha were analyzed. Initial factor analysis using principal components analysis and subsequent orthogonal rotation revealed loading on a four-factor model. Cronbach’s alphas for the instrument/items were 0.89/0.83 to 0.94. Variance explained by the four factors was 58%.

PMID:34935331

Pharm Stat. 2021 Dec 21. doi: 10.1002/pst.2187. Online ahead of print.

ABSTRACT

New technologies for novel biomarkers have transformed the field of precision medicine. However, in applications such as liquid biopsy for early tumor detection, the misclassification rates of next generation sequencing and other technologies have become an unavoidable feature of biomarker development. Because initial experiments are usually confined to specific technology choices and application settings, a statistical method that can project the performance metrics of other scenarios with different misclassification rates would be very helpful for planning further biomarker development and future trials. In this article, we describe an approach based on an extended version of simulation extrapolation (SIMEX) to project the performance of biomarkers measured with varying misclassification rates due to different technological or application settings when experimental results are only available from one specific setting. Through simulation studies for logistic regression and proportional hazards models, we show that our proposed method can be used to project the biomarker performance with good precision when switching from one to anther technology or application setting. Similar to the original SIMEX model, the proposed method can be implemented with existing software in a straightforward manner. A data analysis example is also presented using a lung cancer data set and performance metrics for two gene panel based biomarkers. Results demonstrate that it is feasible to infer the potential implications of using a range of technologies or application scenarios for biomarkers with limited human trial data.

PMID:34935280 | DOI:10.1002/pst.2187

Int J Rheum Dis. 2021 Dec 21. doi: 10.1111/1756-185X.14268. Online ahead of print.

ABSTRACT

AIM: Predicting radiographic progression is vital for assessing the prognosis of patients with radiographic axial spondyloarthritis, and C-reactive protein (CRP) may be a valuable biomarker for this purpose. This study aimed to investigate the relationship between changes in the CRP level and spinal radiographic progression in patients with radiographic axial spondyloarthritis who were initially treated with non-biologics.

METHODS: Patients with radiographic axial spondyloarthritis who were followed up for 18 years at a single center and initially treated with nonsteroidal anti-inflammatory drugs and/or conventional disease-modifying antirheumatic drugs for 3 months were included. Patients with a CRP level of <0.8 mg/dL or 50% of the baseline CRP at 3 months were assigned to the controlled CRP group (n = 351), and the remaining patients were assigned to the uncontrolled CRP group (n = 452). A generalized estimating equation was used to analyze the differences in the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) between the 2 groups.

RESULTS: The increase in the mSASSS was slower in the controlled CRP group than in the uncontrolled CRP group (interaction term β = -.499, 95% confidence interval -0.699 to -0.300).

CONCLUSION: Controlled CRP achieved in response to initial treatment with non-biologic agents for 3 months was significantly associated with a slower rate of spinal radiographic change in patients with radiographic axial spondyloarthritis. The CRP level at 3 months after initial non-biologic treatment is a good predictor of radiographic progression.

PMID:34935282 | DOI:10.1111/1756-185X.14268

J Obstet Gynaecol Res. 2021 Dec 21. doi: 10.1111/jog.15136. Online ahead of print.

ABSTRACT

AIM: The study aimed at investigating pregnancy complications, birth outcomes, and postnatal child development in pregnancies of women with inflammatory bowel diseases (IBDs).

METHODS: This is an uncontrolled retrospective single-center study between 2014 and 2019. It is a mixed-method cross-sectional study using data from (1) electronic patient records and (2) questionnaires and copies of mothers’ and children’s health booklets. Disease activity and IBD medications were analyzed and related to pregnancy complications, birth outcomes, and postnatal child development using mixed models for statistical analyses.

RESULTS: Fifty live births from 46 patients were included. Disease activity anytime during pregnancy occurred in 56%. Biologics were applied in ca. 25% of pregnancies, mostly only through the second trimester. Pregnancies of mothers with active disease were slightly shorter than those of mothers with inactive disease (37.4 weeks vs. 38.9 weeks). Adverse pregnancy outcomes were reported in 28% of the live births, including small for gestational age in 6%, low birth weight in 18%, and preterm birth in 20%. Postnatal developmental abnormalities and health problems were reported in 26.8% of the children. Mixed model analyses failed to reveal significant associations between IBD activity and IBD medications during pregnancy and pregnancy complications, perinatal birth outcomes, and postnatal child development.

CONCLUSION: Despite a tendency of shorter pregnancies in patients with active IBD and lower birth weight and birth size in patients with IBD-related therapy during pregnancy, disease activity and medications did not significantly influence pregnancy, birth, and developmental outcomes.

PMID:34935257 | DOI:10.1111/jog.15136

Eur J Oral Sci. 2021 Dec 22. doi: 10.1111/eos.12838. Online ahead of print.

ABSTRACT

The aim of this study was to evaluate the effect of saliva contamination on bond strength to dentin with an etch-and-rinse and a self-etch adhesive system. For each of these adhesive systems, the dentin surface of 24 human molars were allocated to one of four groups representing different saliva contamination scenarios. Saliva was applied at different stages in the bonding process, and was investigated to be remedied by water rinsing and/or air drying. Uncontaminated tooth surfaces were used as controls. Bonding procedures were performed according to the manufacturer’s instructions, and a polymer-based composite was placed. The bond strength was measured by a micro-tensile test. Except for the etch-and-rinse approach having contamination with saliva after etching, followed by air drying, all salivary contamination regimens resulted in a substantial number of specimens not surviving the test, and the bond strength value of these was therefore set to 0 MPa for the purposes of the statistical analysis. Water rinsing after etching and salivary contamination did significantly reduce the bond strength. Contamination after priming showed the lowest bond strength. For the self-etch approach, saliva contamination before the adhesive procedure, followed by air drying, significantly reduced the bond strength, while contamination followed by water rinsing or air drying did not statistically significantly reduce the strength.

PMID:34935213 | DOI:10.1111/eos.12838