Tag: statistics

J Clin Epidemiol. 2022 Jan 19:S0895-4356(22)00011-7. doi: 10.1016/j.jclinepi.2022.01.005. Online ahead of print.

ABSTRACT

OBJECTIVE: To compare estimates of effect and variability resulting from standard linear regression analysis and hierarchical multilevel analysis with cross-classified multilevel analysis under various scenarios.

STUDY DESIGN AND SETTING: We performed a simulation study based on a data structure from an observational study in clinical mental health care. We used a Markov chain Monte Carlo (MCMC) approach to simulate 18 scenarios, varying sample sizes, cluster sizes, effect sizes and between group variances. For each scenario, we performed standard linear regression, multilevel regression with random intercept on patient level, multilevel regression with random intercept on nursing team level and cross-classified multilevel analysis.

RESULTS: Applying cross-classified multilevel analyses had negligible influence on the effect estimates. However, ignoring cross-classification led to underestimation of the standard errors of the covariates at the two cross-classified levels and to invalidly narrow confidence intervals. This may lead to incorrect statistical inference. Varying sample size, cluster size, effect size and variance had no meaningful influence on these findings.

CONCLUSION: In case of cross-classified data structures, the use of a cross-classified multilevel model helps estimating valid precision of effects, and thereby, support correct inferences.

PMID:35065230 | DOI:10.1016/j.jclinepi.2022.01.005

Pharmacol Res. 2022 Jan 19:106089. doi: 10.1016/j.phrs.2022.106089. Online ahead of print.

ABSTRACT

BACKGROUND: Our study sought to investigate the efficacy and safety of bivalirudin versus those of unfractionated heparin (UFH) in patients undergoing extracorporeal membrane oxygenation (ECMO).

METHODS: PubMed, EMBASE and Cochrane Library were searched for studies enrolling ECMO patients on bivalirudin and UFH (from inception till July 2021). Meta-analysis was conducted. The I² statistic and p value were used in measuring heterogeneity, and random effects or fixed-effect model was adopted. The Newcastle-Ottawa Scale was used for the risk of bias assessment. Sensitivity and subgroup analyses were undertaken. We performed Egger’s test to evaluate publication bias.

RESULTS: Fourteen eligible retrospective observational studies with 1501 subjects were identified. Compared with UFH, bivalirudin significantly reduced the risk of in-circuit thrombosis (OR = 0.44, 95% CI [0.31-0.61], p = 0.000), thrombosis (OR = 0.61, 95% CI [0.45-0.83], p = 0.002) and hospital mortality (OR = 0.78, 95% CI [0.61-0.99], p = 0.04) and had a positive impact on survival ECMO (OR = 1.50, 95% CI [1.04-2.16], p = 0.032). Decrease in risk of bleeding (OR = 0.36, 95% CI [0.14-0.91], p = 0.031) associated with bivalirudin was observed. Sources of heterogeneity were identified, and sensitivity analysis revealed similar results.

CONCLUSION: Our meta-analysis suggested that bivalirudin was associated with the decreased risk of in-circuit thrombosis, thrombosis, hospital mortality and bleeding in patients on ECMO and improved survival ECMO, indicating the superiority of bivalirudin to UFH in terms of efficacy and safety.

PMID:35065202 | DOI:10.1016/j.phrs.2022.106089

J Appl Microbiol. 2022 Jan 22. doi: 10.1111/jam.15461. Online ahead of print.

ABSTRACT

AIMS: Worldwide, studies regarding antimicrobial resistance in rabbits are scarce. In addition, it seems that rearing conditions have important impact on emergence and spread of antimicrobial resistant bacteria. Thus, the authors sought to 1.) assess the role of rabbits residing across diverse ecosystems as potential reservoirs of antimicrobial-resistant enterococci and 2.) investigate the genetic background of detected resistances.

METHODS AND RESULTS: Faecal samples from 60 healthy farmed rabbits (one farm), 35 laboratory rabbits, and 31 wild rabbits were analyzed. Overall, 97 enterococci isolates were accumulated, as follows: 44 E. faecium, 37 E. faecalis, 7 E. gallinarum, 5 E. durans, and 4 E. avium. E. faecalis isolates were statistically associated with farm rabbits and wild rabbits (P < 0.05). High rates of resistance were observed for tetracycline [60.8%; tetM (n = 48; 81.3%), tetO (n = 7; 11.8%), and tetL (n = 1; 1.7%)], erythromycin [43.3%; msr(A) (n = 14; 33.3%) and ermB (n = 13; 31%)], ampicillin [29.9%], streptomycin [26.8%; ant(6)-Ia (n = 3, 11.5%)] , and vancomycin [21.6%; vanA (one E. faecium + one E. faecalis; 9.5%)]. Low frequencies of resistance were observed for teicoplanin [9.2%], linezolid [8.2%], ciprofloxacin [7.2%], and gentamicin [1%; aac(6′)-Ie-aph(2″)-Ia]. Resistance to ampicillin, and vancomycin was associated with laboratory rabbits (P < 0.05). Int-Tn (Tn916/1545) was detected in 27 (27.8%) isolates, of which ten isolates co-harbored tetM and ermB genes, while 16 comprised tetM.

CONCLUSION: Findings indicate that clinically relevant enterococci species isolated from rabbits are frequently resistant to antimicrobials and harbor a range of genes associated with the Tn916/1545 family.

SIGNIFICANCE AND IMPACT OF THE STUDY: This study highlights high rates of antimicrobial-resistant enterococci from rabbits and the occurrence of both vancomycin- and linezolid- resistant isolates, potentially representing a very serious threat to human and animal health.

PMID:35064986 | DOI:10.1111/jam.15461

J Magn Reson Imaging. 2022 Jan 22. doi: 10.1002/jmri.28074. Online ahead of print.

ABSTRACT

BACKGROUND: Dynamic-exponential intravoxel incoherent motion (IVIM) imaging is a potential technique for prediction, monitoring, and differential diagnosis of hepatic diseases, especially liver tumors. However, the use of such technique at voxel level is still limited.

PURPOSE: To develop an unsupervised deep learning approach for voxel-wise dynamic-exponential IVIM modeling and parameter estimation in the liver.

STUDY TYPE: Prospective.

POPULATION: Ten healthy subjects (4 males; age 28 ± 6 years).

FIELD STRENGTH/SEQUENCE: Single-shot spin-echo echo planar imaging (SE-EPI) sequence with monopolar diffusion-encoding gradients (12 b-values, 0-800 seconds/mm² ) at 3.0 T.

ASSESSMENT: The proposed deep neural network (DNN) was separately trained on simulated and in vivo hepatic IVIM datasets. The trained networks were compared to the approach combining least squares with Akaike information criterion (LSQ-AIC) in terms of dynamic-exponential modeling accuracy, inter-subject coefficients of variation (CVs), and fitting residuals on the simulated subsets and regions of interest (ROIs) in the left and right liver lobes. The ROIs were delineated by a radiologist (H.-X.Z.) with 7 years of experience in MRI reading.

STATISTICAL TESTS: Comparisons between approaches were performed with a paired t-test (normality) or a Wilcoxon rank-sum test (nonnormality). P < 0.05 was considered statistically significant.

RESULTS: In simulations, DNN gave significantly higher accuracy (91.6%-95.5%) for identification of bi-exponential decays with respect to LSQ-AIC (79.7%-86.8%). For tri-exponential identification, DNN was also superior to LSQ-AIC despite not reaching a significant level (P = 0.08). Additionally, DNN always yielded comparatively low root-mean-square error for estimated parameters. For the in vivo IVIM measurements, inter-subject CVs (0.011-0.150) of DNN were significantly smaller than those (0.049-0.573) of LSQ-AIC. Concerning fitting residuals, there was no significant difference between the two approaches (P = 0.56 and 0.76) in both the simulated and in vivo studies.

DATA CONCLUSION: The proposed DNN is recommended for accurate and robust dynamic-exponential modeling and parameter estimation in hepatic IVIM imaging.

LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 1.

PMID:35064945 | DOI:10.1002/jmri.28074

CPT Pharmacometrics Syst Pharmacol. 2022 Jan 22. doi: 10.1002/psp4.12763. Online ahead of print.

ABSTRACT

Clinical trials investigate treatment endpoints that usually include measurements of pharmacodynamic and efficacy biomarkers in early phase studies and patient-reported outcomes, as well as event risks or rates in late phase studies. In recent years, a systematic trend in clinical trial data analytics and modeling has been observed, where retrospective data are integrated into a quantitative framework, to prospectively support analyses of interim data and design of ongoing and future studies of novel therapeutics. Joint modeling is an advanced statistical methodology that allows for the investigation of clinical trial outcomes by quantifying the association between baseline and/or longitudinal biomarkers and event risk. Using an exemplar dataset from NSCLC studies, we propose and test a workflow for joint modeling. It allows a modeling scientist to comprehensively explore the data, build survival models, investigate goodness-of-fit, and subsequently perform outcome predictions using interim biomarker data from an ongoing study. The workflow illustrates a full process, from data exploration to predictive simulations, for selected multivariate linear and nonlinear mixed-effects models and software tools in an integrative and exhaustive manner.

PMID:35064957 | DOI:10.1002/psp4.12763

Sports Med. 2022 Jan 22. doi: 10.1007/s40279-021-01635-2. Online ahead of print.

ABSTRACT

BACKGROUND: Physical fitness is a powerful predictor of morbidity and mortality, and is therefore a useful indicator for public health monitoring. To assess physical fitness, field-based tests are time-efficient, inexpensive, have minimal equipment requirements, and can be easily administered to a large number of individuals.

OBJECTIVE: The objective of this systematic review was to examine the reliability of existing field-based fitness tests used in adults aged 19-64 years.

METHODS: A systematic search of two electronic databases (MEDLINE and Web of Science) was conducted from inception to 8 June 2021 by two independent researchers. Each study was classified as high, low, or very low quality according to the description of the participants, the time interval between measurements, the description of the results, and the appropriateness of statistics. Three levels of evidence (strong, moderate, and limited) were established according to the number of studies and the consistency of their findings. The study protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO reference number, CRD42019118480).

RESULTS: Of 17,010 records identified, 129 original studies examining the reliability of field-based fitness tests in adults were considered eligible. The reliability was assessed of tests of cardiorespiratory fitness (33 studies: 30 of high quality), musculoskeletal fitness (92 studies: 78 of high quality), and motor fitness (22 studies, all of high quality). There was strong evidence indicating: (i) the high reliability of the cardiorespiratory fitness tests: 20-m shuttle run, 6-min step, and 6-min walk; (ii) the high reliability of the musculoskeletal fitness tests: handgrip strength, back-leg strength, Sorensen, trunk flexion sustained, 5-reps sit-to-stand, sit-and-reach and toe-touch, and moderate reliability bilateral side bridge and prone bridge tests; and (iii) the moderate reliability and low reliability, respectively, of the motor fitness tests T test and single-leg stand. We found moderate evidence indicating the moderate or high reliability of the following tests: Chester, sit-up, partial curl-up, flexion-rotation trunk, timed stair ascent, pull-up, bent-arm hang, standing broad jump, hop sequence, trunk lift, timed-up-and-go, and hexagon agility. Evidence for the reliability of balance and gait speed tests was inconclusive. Other field-based fitness tests demonstrated limited evidence, mainly due to there being only few studies.

CONCLUSIONS: This review provides an evidence-based proposal of the more reliable field-based fitness tests for adults aged 19-64 years. Our findings identified a need for more high-quality studies designed to assess the reliability of field-based tests of lower and upper body explosive and endurance muscular strength, and motor fitness (i.e., balance and gait speed tests) in adults.

PMID:35064915 | DOI:10.1007/s40279-021-01635-2

Am J Hum Biol. 2022 Jan 22:e23721. doi: 10.1002/ajhb.23721. Online ahead of print.

ABSTRACT

OBJECTIVES: Childhood obesity is a systemic disease with multiple downstream consequences, including shifts in timing of growth and development. It has been documented that children with high body mass index (BMI) show accelerated timing of dental development, but the mechanism for this acceleration is unknown. Prior work has suggested that inflammation and/or nutrition may play a role. We investigate the potential association between diet (caloric intake, macronutrients), obesity, and accelerated dental development.

METHODS: Children and adolescents (age 10-15; n = 112) were recruited from dental clinics at the University of Illinois Chicago. We collected subjects’ height, weight, panoramic radiographic records, and each subject filled out a Block Food Frequency Questionnaire.

RESULTS: The only macronutrient level associated with BMI was a negative correlation to Total Fat consumption (p = .01), though this relationship was not significant in the path analysis (p > .05). Regression analyses indicated that BMI (p = .003) and total caloric intake (controlling for BMI; rho = 0.19; p = .04) were both significantly correlated with timing of dental development. However, when a path analysis was conducted, it was revealed that only BMI was statistically significant (p = .008).

CONCLUSIONS: Body mass index percentile, regardless of caloric intake, is positively associated with accelerated dental development. While it is possible that excess caloric intake itself plays a minor role in timing of dental development, we do not see unambiguous evidence for this in our sample. We posit that another mechanism, such as inflammation, may be the link between obesity status and dental development.

PMID:35064944 | DOI:10.1002/ajhb.23721

Head Neck Pathol. 2022 Jan 22. doi: 10.1007/s12105-022-01413-0. Online ahead of print.

ABSTRACT

Duchenne muscular dystrophy (DMD) is a rare genetic disorder in which patients progressive muscle deterioration and low life expectancy. Since DMD has no cure, treatment slows the deterioration process using corticosteroids and other medications, including oral bisphosphonates (BP). These drugs can lead to toxicities in both soft and hard tissues. The objective of this study was to present cytological changes in DMD patients, comparing to young, healthy individuals. Cytological smears were obtained from buccal mucosa from nine DMD patients and five healthy patients. The Papanicolaou technique was used to stain the slides. Images were captured using a photomicroscope, and 50 clearly defined cells were selected. The size and ratio between the nucleus and cytoplasmic areas (NA/CA) diameter were measured using a computer program. All the DMD patients presented a statistical difference (p < 0.0001) in the size of the cytoplasm (0.60 ± 0.33 μm) and the NA/CA ratio (0.17 ± 0.07 μm) was seen when compared to the control group (cytoplasm 0.60 ± 0.15 µm and nucleus 0.14 ± 0.05 µm). Furthermore, in one DMD in use of BP who presented Medication-Related Osteonecrosis of the Jaw (MRONJ), presented higher differences in the cytoplasmic (1.20 ± 0.65 µm) and nuclear (0.20 ± 0.12 µm) sizes (p < 0.0001) compared with all others DMD patients. These results suggest that the drugs used or the systemic condition of individuals with DMD may contribute to these changes.

PMID:35064903 | DOI:10.1007/s12105-022-01413-0

Oral Radiol. 2022 Jan 22. doi: 10.1007/s11282-022-00587-1. Online ahead of print.

ABSTRACT

OBJECTIVES: To investigate the artefacts caused by different disinfection and protection methods that can be used for infection control of photostimulable phosphor (PSP) plates.

METHODS: The plates that were enveloped with single or double envelopes were sprayed with an alcohol-containing solution or wiped with an alcohol-containing tissue. Four PSP groups with two plates in each group were formed (A = wiping single envelope, B = wiping double envelopes, C = spraying onto single envelope, and D = spraying onto double envelopes). Any artefacts (1 = no artefact, 2 = presence of artefact less than 0.5 cm wide, and 3 = presence of artefact larger than 0.5 cm wide) on the 12 acquired images were evaluated.

RESULTS: Artefacts (score-3) occurred on the images of Group C-2 PSP plate after the 3rd exposure. According to the Kruskal-Wallis test the difference between the artefact score of the four methods was found significant. Post-hoc comparisons showed the Group C artefact scores were higher than the others and the difference was significant. The total time of enveloping and disinfection processes for groups was; A = 6.30 min, B = 7.58 min, C = 5.48 min, and D = 7.14 min.

CONCLUSIONS: Regardless of the number of envelopes, wiping with a tissue was less likely to cause artefacts, while spraying was reliable only when double envelopes were used. However, using a tissue and double envelopes, which are less risky in terms of artefact, causes time loss, difficulty in manipulation, environmental pollution and high cost.

PMID:35064886 | DOI:10.1007/s11282-022-00587-1

Prev Sci. 2022 Jan 22. doi: 10.1007/s11121-022-01338-8. Online ahead of print.

ABSTRACT

Using data from the Florida Maternal, Infant, and Early Childhood Home Visiting (MIECHV) funded programs, we examined program- and participant-level characteristics associated with participant retention by time of enrollment. Analyses of data for 1,807 women enrolled in 11 sites across three years included descriptive statistics; Kaplan-Meier survival curve estimation and multilevel survival analyses using shared frailty model to assess participant- and program-level characteristics overall and by time of enrollment (during pregnancy or post-delivery). Median retention time for MIECHV participants was 462 days. The primary reason for attrition was loss-to-follow-up (59.4%) due to change of address/telephone. We found participant age > 25 years (compared to < 20 years), enrollment during pregnancy, and an average of 1.5-2.0 home visit/month to be protective, while current/history of substance abuse was a risk factor for attrition. To improve participant retention, the Florida MIECHV program may need to bolster efforts to support housing stability, increase outreach and engagement to younger women, address barriers to achieving two home visits per month throughout the program, and target differential predictors of participant attrition depending on time of enrollment.

PMID:35064893 | DOI:10.1007/s11121-022-01338-8