Tag: statistics

J Public Health Dent. 2021 Mar 29. doi: 10.1111/jphd.12452. Online ahead of print.

ABSTRACT

OBJECTIVES: To investigate the prevalence and factors associated with dental pain and its impact on the quality of life of adult and elderly homeless people in Midwest Brazil.

METHODS: A cross-sectional study was conducted with 353 individuals aged ≥18 attending a public homeless shelter in a Brazilian state capital (Goiânia). Data on sociodemographic, psychosocial, drug use and oral health-related factors, and quality of life [Oral Impact on Daily Performance scale (OIDP)] were collected through interviews. Pearson’s Chi-square tests and robust Poisson regression were used for statistical analysis.

RESULTS: The prevalence of dental pain in the past 6 months was 50 percent. Most of the respondents reported very severe pain and self-management including medication and tooth extraction. In the adjusted regression, the prevalence of pain was 1.48 times higher among individuals who last visited the dentist within the past 2 years, compared to those who had visited more than 2 years ago; and nearly five times higher among those with a perceived need for dental treatment, compared to those with no need. The prevalence of oral impact on daily performance was 80.1 percent and the most affected activities were “difficulty eating” and “feeling ashamed to smile or speak.” The adjusted prevalence of impact was higher among individuals who had dental pain, regardless of their sociodemographic characteristics.

CONCLUSIONS: The prevalence, intensity, and self-management of dental pain were high among the Brazilian homeless people studied. Reporting of pain was associated with factors related to dental care and negatively affected their quality of life.

PMID:33782969 | DOI:10.1111/jphd.12452

Stat Med. 2021 Mar 29. doi: 10.1002/sim.8960. Online ahead of print.

ABSTRACT

Clinical studies on periodontal disease (PD) often lead to data collected which are clustered in nature (viz. clinical attachment level, or CAL, measured at tooth-sites and clustered within subjects) that are routinely analyzed under a linear mixed model framework, with underlying normality assumptions of the random effects and random errors. However, a careful look reveals that these data might exhibit skewness and tail behavior, and hence the usual normality assumptions might be questionable. Besides, PD progression is often hypothesized to be spatially associated, that is, a diseased tooth-site may influence the disease status of a set of neighboring sites. Also, the presence/absence of a tooth is informative, as the number and location of missing teeth informs about the periodontal health in that region. In this paper, we develop a (shared) random effects model for site-level CAL and binary presence/absence status of a tooth under a Bayesian paradigm. The random effects are modeled using a spatial skew-normal/independent (S-SNI) distribution, whose dependence structure is conditionally autoregressive (CAR). Our S-SNI density presents an attractive parametric tool to model spatially referenced asymmetric thick-tailed structures. Both simulation studies and application to a clinical dataset recording PD status reveal the advantages of our proposition in providing a significantly improved fit, over models that do not consider these features in a unified way.

PMID:33782991 | DOI:10.1002/sim.8960

Biotechnol Bioeng. 2021 Mar 30. doi: 10.1002/bit.27767. Online ahead of print.

ABSTRACT

Straight-through chromatography, wherein the eluate from one column passes directly onto another column without adjustment, is one strategy to integrate and intensify manufacturing processes for biologics. Development and optimization of such straight-through chromatographic processes is a challenge, however. Conventional high-throughput screening methods optimize each chromatographic step independently, with limited consideration for the connectivity of steps. Here, we demonstrate a method for the development and optimization of fully integrated, multi-column processes for straight-through purification. Selection of resins was performed using an in-silico tool for the prediction of processes for straight-through purification based on a one-time characterization of host-cell proteins combined with the chromatographic behavior of the product. A two-step optimization was then conducted to determine the buffer conditions that maximized yield while minimizing process- and product-related impurities. This optimization of buffer conditions included a series of range-finding experiments on each individual column, similar to conventional screening, followed by the development of a statistical model for the fully integrated, multi-column process using design of experiments (DoE). We used this methodology to develop and optimize integrated purification processes for a single-domain antibody and a cytokine, obtaining yields of 88% and 86%, respectively, with process- and product-related variants reduced to phase-appropriate levels for nonclinical material. This article is protected by copyright. All rights reserved.

PMID:33782945 | DOI:10.1002/bit.27767

Child Dev. 2021 Mar 29. doi: 10.1111/cdev.13552. Online ahead of print.

ABSTRACT

This study examines whether changes in classroom quality predict within-child changes in achievement and behavioral problems in elementary school (ages spanning approximately 6-11 years old). Drawing on data from a longitudinal study of children in predominantly low-income, nonurban communities (n = 1,078), we relied on child fixed effects modeling, which controlled for stable factors that could bias the effects of classroom quality. In general, we found that changes in classroom quality had small and statistically nonsignificant effects on achievement and behavior. However, we found that moving into a high-quality classroom, particularly those rated as high in Classroom Organization, had positive effects on achievement and behavior for children with significant exposure to poverty in early life.

PMID:33782953 | DOI:10.1111/cdev.13552

Am J Phys Anthropol. 2021 Mar 30. doi: 10.1002/ajpa.24275. Online ahead of print.

ABSTRACT

OBJECTIVES: Some previous studies suggest that humans do not conform to geometric similarity (isometry) in anthropometric dimensions of the upper and lower limbs. Researchers often rely on a single statistical approach to the study of scaling patterns, and it is unclear whether these methods produce similar results and are equally robust. This study used one bivariate and one multivariate method to examine how linear anthropometric dimensions scale in a sample of adult humans.

MATERIALS AND METHODS: Motion capture marker data from 104 adults of varying height and mass were used to calculate anthropometric dimensions. We analyzed scaling patterns in pooled and separate sexes with two methods: (1) bivariate log-log regression and (2) multivariate principal component analysis (PCA). We calculated 95% highest density/confidence intervals for each method and defined positive/negative allometry as estimates lying outside those intervals.

RESULTS: Results identified isometric scaling of the upper arm, thigh, and shoulder, positive allometry of the forearm and shank, and negative allometry of the pelvis in the pooled sample using both statistical methods. Patterns of allometry in the pooled sample were similar between methods but differed in magnitude. Sex-specific results differed in both pattern and magnitude between log-log regression and PCA. Only one measurement (shoulder width) departed from isometry in the sex-specific log-log regressions.

DISCUSSION: Our findings suggest that especially in sex-specific analyses, the pattern and magnitude of allometry are sensitive to statistical methodology. When body mass was selected as the size variable, most human linear anthropometric dimensions in this sample scaled isometrically and were therefore geometrically similar within sexes.

PMID:33782957 | DOI:10.1002/ajpa.24275

Z Orthop Unfall. 2021 Mar 29. doi: 10.1055/a-1401-0477. Online ahead of print.

ABSTRACT

INTRODUCTION: The purpose of this study was to evaluate the relationship between the correction rate in Cobb angle and the improvement in quality of life profile in terms of Scoliosis Research Society (SRS)-22 values.

PATIENTS AND METHODS: Between January 2007 and December 2013, posterior instrumentation and fusion was performed to 30 patients with adolescent idiopathic scoliosis (AIS). Patients were grouped according to their improvement rate in Cobb angles after surgery. Patients with an improvement rate of > 80% were grouped as Group A; those with an improvement rate of > 60% and ≤ 80% as Group B and those with an improvement rate of ≤ 60% were grouped as Group C. The SRS-22 questionnaire of these three groups was calculated and their relationship with the improvement in Cobb angle was evaluated.

RESULTS: No statistical difference was found among the three groups in terms of pain, appearance, function, spirit, satisfaction, and SRS-22 values (all p > 0.05).

CONCLUSION: The results of this study demonstrate that the degree of correction rate does not correlate with the degree of improvement in the SRS-22 questionnaire in patients with AIS that underwent posterior fusion and instrumentation.

PMID:33782933 | DOI:10.1055/a-1401-0477

Transplant Cell Ther. 2021 Mar;27(3):261.e1-261.e7. doi: 10.1016/j.jtct.2020.12.019. Epub 2020 Dec 22.

ABSTRACT

Central nervous system (CNS) involvement in Epstein-Barr virus-related post-transplant lymphoproliferative disorders (EBV-PTLDs) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is poorly defined. We analyzed the incidence, clinical and pathological characteristics, and impact on outcomes of EBV-PTLDs with CNS involvement (CNS-PTLDs) in 1009 consecutive adult patients undergoing allo-HSCT at a single-center institution. Four hundred eighty-two patients received matched sibling donor (MSD) transplants, 388 umbilical cord blood transplants (UCBTs), 56 matched unrelated donor (MUD) transplants, and 83 haploidentical transplants. We detected 25 cases of biopsy-proven EBV-PTLDs. Of these, nine patients (36%) had CNS-PTLDs: six after UCBT (67%), one after MSD transplantation (11%), one after MUD transplantation (11%), and one after haploidentical transplantation (11%). The 5-year cumulative incidence risk of CNS-PTLDs was 0.9%. Median time from transplant to CNS-PTLDs was 187 days, and all patients had neurological symptoms at diagnosis. Six out of the nine cases (67%) occurred with systemic involvement, and three cases (33%) had isolated CNS involvement. The most frequent histological subtype was monomorphic EBV-PTLD, and laboratory characteristics were similar to EBV-PTLDs without CNS involvement. We observed statistical differences in the rate of positive EBV DNA detection in plasma between isolated CNS-PTLDs (detection in one out of three, 33%) and the rest of the EBV-PTLDs (100%) (P = .01). Treatment strategies included chemotherapy, radiotherapy, and T cell therapy. However, seven out of nine patients died due to progression of the CNS-PTLDs at a median time of 17 days (range, 8 to 163) from diagnosis. The 5-years overall survival in patients who developed CNS-PTLDs was 22% (95% confidence interval [CI], 7% to 75%) and 5-year treatment-related mortality was 78% (95% CI, 51% to 100%), with no statistically significant differences between CNS-PTLDs and the rest of the EBV-PTLDs. In conclusion, despite advances in EBV monitoring and treatment strategies, CNS-PTLDs remain an uncommon but serious complication after allo-HSCT, with very poor prognosis.

PMID:33781531 | DOI:10.1016/j.jtct.2020.12.019

Transplant Cell Ther. 2021 Mar;27(3):262.e1-262.e11. doi: 10.1016/j.jtct.2021.01.004. Epub 2021 Jan 7.

ABSTRACT

Bloodstream infections (BSIs) occur in 20% to 45% of inpatient autologous and allogeneic hematopoietic cell transplant (HCT) patients. Daily bathing with the antiseptic chlorhexidine gluconate (CHG) has been shown to reduce the incidence of BSIs in critically ill patients, although very few studies include HCT patients or have evaluated the impact of compliance on effectiveness. We conducted a prospective cohort study with historical controls to assess the impact of CHG bathing on the rate of BSIs and gut microbiota composition among adults undergoing inpatient HCT at the Duke University Medical Center. We present 1 year of data without CHG bathing (2016) and 2 years of data when CHG was used on the HCT unit (2017 and 2018). Because not all patients adhered to CHG, patients were grouped into four categories by rate of daily CHG usage: high (>75%), medium (50% to 75%), low (1% to 49%), and none (0%). Among 192 patients, univariate trend analysis demonstrated that increased CHG usage was associated with decreased incidence of clinically significant BSI, defined as any BSI requiring treatment by the medical team (high, 8% BSI; medium, 15.2%; low, 15.6%; no CHG, 30.3%; P = .003), laboratory-confirmed BSI (LCBI; P = .03), central line-associated BSI (P = .04), and mucosal barrier injury LCBI (MBI-LCBI; P = .002). Multivariate analysis confirmed a significant effect of CHG bathing on clinically significant BSI (P = .023) and MBI-LCBI (P = .007), without consistently impacting gut microbial diversity. Benefits of CHG bathing were most pronounced with >75% daily usage, and there were no adverse effects attributable to CHG. Adherence to daily CHG bathing significantly decreases the rate of bloodstream infection following HCT.

PMID:33781532 | DOI:10.1016/j.jtct.2021.01.004

Transplant Cell Ther. 2021 Mar;27(3):274.e1-274.e5. doi: 10.1016/j.jtct.2020.12.024. Epub 2020 Dec 25.

ABSTRACT

Data on stem cell transplantation (SCT) for Diamond-Blackfan Anemia (DBA) is limited. We studied patients transplanted for DBA and registered in the EBMT database. Between 1985 and 2016, 106 DBA patients (median age, 6.8 years) underwent hematopoietic stem cell transplantation from matched-sibling donors (57%), unrelated donors (36%), or other related donors (7%), using marrow (68%), peripheral blood stem cells (20%), both marrow and peripheral blood stem cells (1%), or cord blood (11%). The cumulative incidence of engraftment was 86% (80% to 93%), and neutrophil recovery and platelet recovery were achieved on day +18 (range, 16 to 20) and +36 (range, 32 to 43), respectively. Three-year overall survival and event-free survival were 84% (77% to 91%) and 81% (74% to 89%), respectively. Older patients were significantly more likely to die (hazard ratio, 1.4; 95% confidence interval, 1.06 to 1.23; P < .001). Outcomes were similar between sibling compared to unrelated-donor transplants. The incidence of acute grades II to IV of graft-versus-host disease (GVHD) was 30% (21% to 39%), and the incidence of extensive chronic GVHD was 15% (7% to 22%). This study shows that SCT may represent an alternative therapeutic option for transfusion-dependent younger patients.

PMID:33781541 | DOI:10.1016/j.jtct.2020.12.024

Med Eng Phys. 2021 Apr;90:1-8. doi: 10.1016/j.medengphy.2021.01.009. Epub 2021 Feb 16.

ABSTRACT

This paper addresses an important issue faced by neurosurgeons during surgical skull bone grinding, a common process used to remove bone in skull base tumour removal surgery to enable the neurosurgeon to reach the target region. The heat generated during bone grinding could harm the soft tissues and can lead to osteonecrosis and cell death. In the present study, a novel process of rotary ultrasonic bone grinding (RUBG) was proposed for osteotomy to limit the temperature to a safe level. A systematic investigation was conducted to determine the effect of varying process parameters on osteonecrosis at the cut surface. Three input parameters – rotational speed, feed rate and frequency – were investigated (at three levels) in terms of change in temperature and thermal biological damage. A sterile solution was used as a coolant to irrigate the grinding zone. Viable lacunae (filled osteocytes), non-viable lacunae (empty lacunae), necrosed tissues, and Haversian canal were found during the histological examination. Statistical analysis revealed that feed rate (45.43%) had the highest contribution towards temperature rise during grinding, followed by ultrasonic frequency (23.87%), and rotational speed (12.85%). The optimal machining parameters to avoid osteonecrosis and thermal trauma were rotational speed 35,000 rpm, feed rate 20 mm/min and ultrasonic frequency 20 kHz. Furthermore, histograms revealed that ultrasonic skull bone grinding was associated with greater cell viability and reduced temperature compared with conventional bone grinding.

PMID:33781475 | DOI:10.1016/j.medengphy.2021.01.009