Tag: statistics

J Surg Res. 2021 Nov 23;270:555-563. doi: 10.1016/j.jss.2021.09.009. Online ahead of print.

ABSTRACT

BACKGROUND: All-terrain vehicle (ATV) use is widespread, however, little is known about injury patterns and outcomes in geriatric patients. We hypothesized that geriatric patients would have distinct and more severe injuries than non-geriatric adults after ATV trauma.

METHODS: A retrospective cohort study was performed using the National Trauma Databank comparing non-geriatric (18-64) and geriatric adults (≥65) presenting after ATV trauma at Level 1 and 2 trauma centers from 2011 to 2015. Demographic, admission, and outcomes data were collected, including injury severity score (ISS), abbreviated injury scale (AIS) score, discharge disposition, and mortality. We performed univariate statistical tests between cohorts and multiple logistic regression models to assess for risk factors associated with severe injury (ISS>15) and mortality.

RESULTS: 23,568 ATV trauma patients were identified, of whom 1,954 (8.3%) were geriatric. Geriatric patients had higher rates of severe injury(29.2 v 22.5%,p<0.0001), and thoracic (55.2 v 37.8%,p<0.0001) and spine (31.5 v 26.0%,p<0.0001) injuries, but lower rates of abdominal injuries (14.6 v 17.9%,p<0.001) as compared to non-geriatric adults. Geriatric patients had overall lower head injury rates (39.2 v 42.1%,p=0.01), but more severe head injuries (AIS>3) (36.2 vs 30.2%,p<0.001). Helmet use was significantly lower in geriatric patients (12.0 v 22.8%,p<0.0001). On multivariate analysis age increased the odds for both severe injury (OR 1.50, 95% CI 1.31-1.72, p<0.0001) and mortality (OR 5.07, 95% CI 3.42-7.50, p<0.0001).

CONCLUSIONS: While severe injury and mortality after ATV trauma occurred in all adults, geriatric adults suffered distinct injury patterns and were at greater risk for severe injury and mortality.

LEVEL OF EVIDENCE: Level IV STUDY TYPE: Retrospective review of National Database.

PMID:34826691 | DOI:10.1016/j.jss.2021.09.009

Gait Posture. 2021 Nov 17;92:65-70. doi: 10.1016/j.gaitpost.2021.11.007. Online ahead of print.

ABSTRACT

BACKGROUND: Dual-task walking (DTW) is common in daily life and represents an ideal paradigm for elucidating gait irregularity. Under single-task walking (STW) and DTW conditions, the symmetric and bilaterally coordinated human gait pattern found in healthy individuals is absent in individuals with neurological ailments such as Parkinson’s disease, Alzheimer’s disease and post-stroke issues. Cerebral small vessel disease (CSVD) is a neuropathological and radiological issue that has been reported to be associated with cognitive and motor disorders. However, few gait analyses have focused on elderly individuals with CSVD under DTW conditions.

RESEARCH QUESTION: Are parameters of gait analysis helpful in elucidating gait abnormalities in elderly patients with CSVD under DTW conditions?

METHODS: A total of 46 elderly patients with CSVD (CSVD group) and 22 healthy, age-matched individuals (HE group) were recruited. Gait data were collected from both groups under STW and DTW conditions. Direct parameters and metrics reflecting gait variability, gait asymmetry, and bilateral coordination of gait in the two groups were compared.

RESULTS: Under STW conditions, elderly individuals with CSVD showed markedly shorter stride length, were slower, and had higher gait asymmetry (GA) and phase coordination index (PCI) than healthy controls after adjusting for age, sex and level of education. Under DTW conditions, there were statistically significant differences between the two groups in stride time, stride length, cadence, stride time variability, GA and PCI after adjusting for age, sex, and level of education.

SIGNIFICANCE: Reanalysis-generated parameters, such as gait variability, GA, and PCI, are biomarkers for gait dysfunction in elderly patients with CSVD. In this study, elderly individuals with CVSD showed abnormal gait features under both STW and DTW conditions.

PMID:34826695 | DOI:10.1016/j.gaitpost.2021.11.007

Immunobiology. 2021 Nov 19;227(1):152154. doi: 10.1016/j.imbio.2021.152154. Online ahead of print.

ABSTRACT

Vulvovaginal candidiasis is one of the most commonly reported female genital tract infections, affecting approximately 70-75% of childbearing age women at least once during their lifetime. Approximately 50% of patients have refractory episodes and in 5-10% of cases the disease has a chronic course. The fungal cell wall represents the important host-invader interface. Cell-wall polysaccharides represent biological response modifiers and the pathogen-associated molecular patterns and virulence factors. Glycans are sensed by germ-line encoded pattern recognition receptors and reactively participate in immune system cell signaling. The most dominant cell-wall antigenic structures of Candida species as ß-glucan, α- and ß-mannans, glucomannan and other immunogenic polysaccharides are of particular relevancy for specific in vitro diagnosis and long-term follow-up of the Candida infection. In this study we assessed the immunobiological activity of facultative pathogen Candida utilis cell glucomannan and its effectivity as in vitro serological marker for antibody testing. The novel serologic assay has been developed and optimized for C. utilis serodiagnosis. The comparison assays were performed to establish relationship between antibodies against C. utilis, C. albicans and S. cerevisiae main cell-wall antigens in patient sera. The study evaluates applicability of glucomannan as serodiagnostic antigen and as a trigger of antigenspecific IgG, IgM and IgA antibody isotypes in the cohort of 35 atopic female subjects with recurrent vulvovaginal candidiasis. Statistically significant sera values of specific anti-glycan IgM and IgA class antibodies were revealed. The results are suggestive for efficient serological application of C.utilis glucomannan as in vitro disease marker and prospectively for follow-up of the specific long-term antimycotic therapy.

PMID:34826687 | DOI:10.1016/j.imbio.2021.152154

Eur J Obstet Gynecol Reprod Biol. 2021 Nov 16;267:221-225. doi: 10.1016/j.ejogrb.2021.11.015. Online ahead of print.

ABSTRACT

OBJECTIVE: The aim of this study was to investigate long-term post-recurrence survival outcomes in young women receiving fertility-sparing surgery (FSS) to verify the feasibility of the limited surgery for epithelial ovarian cancer (OvCa).

STUDY DESIGN: We performed a regional multicenter retrospective study from January 1986 and March 2020, using clinical data corrected under the central pathological review system. Patients with recurrent tumor after surgery for stage I epithelial OvCa, aged equal or younger than 45 years were included for this study. We evaluated effect of FSS regarding long-term post-recurrence survival with statistical adjustment of propensity score-based method.

RESULTS: With the Kaplan-Meier method, original and adjusted survival curves were estimated for recurrence-after survival of patients with (n = 14) and without FSS (n = 26). Median time to disease-specific death was 18.6 months. In both original and adjusted cohorts, there were no significant difference between the two groups (log rank test; P > 0.05). Hazard ratio of disease-specific death was 1.264 (95% confidence interval, 0.563-2.836; P = 0.570) in original and 1.354 (95% confidence interval, 0.702-2.611; P = 0.366) in adjusted population. This result indicated that patients with FSS was not associated with poorer prognosis for recurrence-after survival than those without. When comparing patients not receiving FSS, patients receiving FSS with recurrence at spared ovary followed not significantly different survival outcome as well as those with extra-ovarian recurrence.

CONCLUSION: There was no significant difference of long-term post-recurrence survival outcomes between patients of epithelial OvCa with and without FSS in young women of reproductive age.

PMID:34826670 | DOI:10.1016/j.ejogrb.2021.11.015

Vet Immunol Immunopathol. 2021 Nov 18;243:110362. doi: 10.1016/j.vetimm.2021.110362. Online ahead of print.

ABSTRACT

Ferrets are nowadays frequently used as animal models for biomedical purposes; in many cases, immunosuppression of experimental animals is necessary. The aim of this study was to evaluate the effect of intramuscular dexamethasone administration (2 mg/kg as the initiation dose continued with 1 mg/kg q 12 h applied 5 times) on ferret’s immune system. In comparison with ferrets which received the saline (n = 5), significantly lower total counts of leukocytes (P < 0.01), lymphocytes (P < 0.01) and monocyte (P < 0.05), as well as absolute numbers of CD4+CD8- (P < 0.01) and CD4-CD8+ (P < 0.01) subsets were noted in dexamethasone treated ferrets (n = 5) the first day after the treatment (D1). Absolute number of CD79+ lymphocytes remained unchanged throughout the experiment. The proliferation activity of lymphocytes in dexamethasone treated ferrets was lower only in D1 using concanavalin A (conA), phytohemagglutinin (PHA) and pokeweed mitogen (PWM); statistical significance was noted using PHA 40 (P < 0.05) and PWM 10 (P < 0.01). Lower neutrophil activity (P < 0.01) was detected in D1 after the dexamethasone treatment in both production of reactive oxygen species (chemiluminescence test) and ingestion of particles (phagocytosis assay). The dexamethasone treatment proved to be useful for short-term immunosuppression in ferrets. The results closely resembled data previously reported in human studies and indicate classification of ferrets as steroid-resistant species.

PMID:34826685 | DOI:10.1016/j.vetimm.2021.110362

Behav Processes. 2021 Nov 23:104550. doi: 10.1016/j.beproc.2021.104550. Online ahead of print.

ABSTRACT

The number, duration and depth of social relationships that individuals maintain impact social cognition, but the connection between sociality and other aspects of cognition has hardly been explored. To date, the link between social living and intelligence has been mainly supported by studies on primates, and far fewer tests connecting sociality to cognitive abilities have used other taxa. Here, we present the first comparative study in fishes that examines whether complex social living is associated with better performance on a cognitively demanding spatial task. Using three cooperative, group-living cichlid fish species and three of their non-cooperative, more solitary close relatives, we studied maze learning and employed a new statistical extension for the ‘lme4’ and ‘glmmTMB’ packages in R that allows phylogeny to be included as a random effect term. Across trials, the three cooperative and the three non-cooperative species completed the maze faster, made fewer mistakes, and improved their inhibitory control. Although fish improved their performance, we did not detect any differences in the extent of improvement between cooperative and non-cooperative species. Both the cooperative species and the non-cooperative species took similar amounts of time to complete the maze, had comparable numbers of mistakes, and exhibited similar inhibitory control while in the maze. Our results suggest that living and breeding in complex social groups does not necessarily imply enhancement of other forms of cognition nor, more specifically, an enhanced spatial learning capacity.

PMID:34826584 | DOI:10.1016/j.beproc.2021.104550

J Biomed Inform. 2021 Nov 23:103959. doi: 10.1016/j.jbi.2021.103959. Online ahead of print.

ABSTRACT

BACKGROUND: Scoring systems are highly interpretable and widely used to evaluate time-to-event outcomes in healthcare research. However, existing time-to-event scores are predominantly created ad-hoc using a few manually selected variables based on clinician’s knowledge, suggesting an unmet need for a robust and efficient generic score-generating method.

METHODS: AutoScore was previously developed as an interpretable machine learning score generator, integrated both machine learning and point-based scores in the strong discriminability and accessibility. We have further extended it to the time-to-event outcomes and developed AutoScore-Survival, for generating time-to-event scores with right-censored survival data. Random survival forest provided an efficient solution for selecting variables, and Cox regression was used for score weighting. We implemented our proposed method as an R package. We illustrated our method in a study of 90-day survival prediction for patients in intensive care units and compared its performance with other survival models, the random survival forest, and two traditional clinical scores.

RESULTS: The AutoScore-Survival-derived scoring system was more parsimonious than survival models built using traditional variable selection methods (e.g., penalized likelihood approach and stepwise variable selection), and its performance was comparable to survival models using the same set of variables. Although AutoScore-Survival achieved a comparable integrated area under the curve of 0.782 (95% CI: 0.767-0.794), the integer-valued time-to-event scores generated are favorable in clinical applications because they are easier to compute and interpret.

CONCLUSIONS: Our proposed AutoScore-Survival provides a robust and easy-to-use machine learning-based clinical score generator to studies of time-to-event outcomes. It gives a systematic guideline to facilitate the future development of time-to-event scores for clinical applications.

PMID:34826628 | DOI:10.1016/j.jbi.2021.103959

Neurotoxicol Teratol. 2021 Nov 23:107052. doi: 10.1016/j.ntt.2021.107052. Online ahead of print.

ABSTRACT

This study was designed to assess whether prenatal cocaine exposure (PCE) is associated with sex differences in behavior problems in middle childhood and whether there are sex differences in the way in which parasympathetic functioning mediates the relations between PCE and behavior problems within a diverse low-income sample. Participants included 164 high risk mother-child dyads including 89 PC exposed children and 75 control children participating in an ongoing longitudinal study. Respiratory sinus arrhythmia (RSA) was measured to assess parasympathetic functioning at 13 months of age and maternal reports of child behavior problems were collected at 7 years of age. Results revealed no significant association between PCE and behavior problems for the full sample. A 2 × 2 Anova revealed a significant interaction between PCE and child sex on internalizing, externalizing, and total behavior problems (F (3, 160) = 13.45, p < .001) with cocaine exposed females averaging the highest behavior problem scores. Results also revealed a statistically significant indirect effect linking cocaine exposure to lower externalizing problems via lower baseline RSA among males. Findings indicate that cocaine exposed females may be more vulnerable to developing behavior problems than cocaine exposed males and that high baseline RSA may present a sex specific risk factor for externalizing problems among exposed males.

PMID:34826569 | DOI:10.1016/j.ntt.2021.107052

Int J Biostat. 2021 Jan 13;17(2):317-329. doi: 10.1515/ijb-2020-0136.

ABSTRACT

Gradient boosting from the field of statistical learning is widely known as a powerful framework for estimation and selection of predictor effects in various regression models by adapting concepts from classification theory. Current boosting approaches also offer methods accounting for random effects and thus enable prediction of mixed models for longitudinal and clustered data. However, these approaches include several flaws resulting in unbalanced effect selection with falsely induced shrinkage and a low convergence rate on the one hand and biased estimates of the random effects on the other hand. We therefore propose a new boosting algorithm which explicitly accounts for the random structure by excluding it from the selection procedure, properly correcting the random effects estimates and in addition providing likelihood-based estimation of the random effects variance structure. The new algorithm offers an organic and unbiased fitting approach, which is shown via simulations and data examples.

PMID:34826371 | DOI:10.1515/ijb-2020-0136

Int J Biostat. 2020 Dec 2;17(2):331-348. doi: 10.1515/ijb-2020-0022.

ABSTRACT

We propose a nonparametric test of independence, termed optHSIC, between a covariate and a right-censored lifetime. Because the presence of censoring creates a challenge in applying the standard permutation-based testing approaches, we use optimal transport to transform the censored dataset into an uncensored one, while preserving the relevant dependencies. We then apply a permutation test using the kernel-based dependence measure as a statistic to the transformed dataset. The type 1 error is proven to be correct in the case where censoring is independent of the covariate. Experiments indicate that optHSIC has power against a much wider class of alternatives than Cox proportional hazards regression and that it has the correct type 1 control even in the challenging cases where censoring strongly depends on the covariate.

PMID:34826372 | DOI:10.1515/ijb-2020-0022