Tag: statistics

Contemp Clin Trials. 2021 Mar 6:106336. doi: 10.1016/j.cct.2021.106336. Online ahead of print.

ABSTRACT

Matched-pair cluster randomization design is becoming increasingly used in clinical and health behavioral studies. Investigators often encounter incomplete observations in the data collected. Statistical inference for matched-pair cluster randomization design with incomplete observations has been extensively studied in literature. However, sample size method for such study design is sparsely available. We propose a closed-form sample size formula for matched-pair cluster randomization design with continuous outcomes, based on the generalized estimating equation approach by treating incomplete observations as missing data in a marginal linear model. The sample size formula is flexible to accommodate different correlation structures, missing patterns, and magnitude of missingness. In the presence of missing data, the proposed method would lead to a more accurate sample size estimation than the crude adjustment method. Simulation studies are conducted to evaluate the finite-sample performance of the proposed sample size method under various design configurations. We use bias-corrected variance estimators to address the issue of inflated type I error when the number of clusters per group is small. A real application example of physical fitness study in Ecuadorian adolescents is presented for illustration.

PMID:33689919 | DOI:10.1016/j.cct.2021.106336

Res Vet Sci. 2021 Mar 2;136:209-219. doi: 10.1016/j.rvsc.2021.02.025. Online ahead of print.

ABSTRACT

Stray cat population management is an important worldwide issue. Understanding citizen attitudes towards stray cat control options is vital to the success of controlling stray cat numbers, as public perception affects the acceptance of, support for and collaboration in stray cat management policies. Audience segmentation, as to enable each group to be engaged in the stray cat management policy, is important for the success of the interventions. Therefore a web-based survey was conducted among Flemish citizens in order to examine differences in acceptance towards seven management scenarios: household cat neutering with financial support for the owner, household cat neutering without financial support for the owner, encouraging responsible household cat ownership, trapping stray cats and taking them to a shelter, trapping and neutering stray cats for release into a managed “cat colony” (composed by so called “community cats”), trapping and killing of stray cats, and undertaking no action. A total of 4059 valid responses were collected and the proportions of agreement were compared across the different management scenarios using the two-sample z-test. Interactions among factors that influenced each management scenario were investigated using the CHAID (Chi-squared Automatic Interaction Detection) analysis and visualized on a tree. Our results showed that fostering responsible household cat ownership (89.9%) and conversion of stray cats to “community cats” (76.3%) were most supported by respondents in our sample (which consisted mainly of females, cat-lovers, and families without children). Least supported were the killing of stray cats (7.7%) and undertaking no action (3.3%). The demographic analyses revealed that for the acceptance of management scenarios there were three important factors (attitude towards cats, area of residence, and gender), two weaker factors (education and having children) and two which had almost no impact (age and cat ownership). We propose that future studies should focus on the effect of ‘area of residence’, ‘having children’ and ‘education’. In conclusion, our research confirms that management of and communication on stray cat strategies should not be developed with a one-size-fits-all approach. Efforts should be tailored to each audience segment, thus adapted to the area of residence and human characteristics.

PMID:33689877 | DOI:10.1016/j.rvsc.2021.02.025

Thorac Cancer. 2021 Mar 10. doi: 10.1111/1759-7714.13778. Online ahead of print.

ABSTRACT

BACKGROUND: Here, we report our initial experience with subxifoid video-assisted thoracoscopic surgery (SVATS) lobectomy for the management of primary lung cancer, and compared the outcomes of SVATS with those of conventional transthoracic VATS (CVATS) lobectomies to validate its feasibility and usefulness.

METHODS: The clinical data of consecutive patients undergoing VATS lobectomy via SVATS or CVATS for lung cancer were retrospectively compared. The endpoints were to evaluate the statistical differences in surgical results, postoperative pain (measured with visual analog scale [VAS] scores at 8 hours, Day 1, Day 2, Day 3, at discharge, one month and three months after surgery) and paresthesia (measured at one- month, and three months after surgery). The two groups were compared before and after matching analysis.

RESULTS: Our study population included 223 patients: 84 in the SVATS and 139 in the CVATS group. The two groups were not comparable for sex (P = 0.001), preoperative comorbidity as cardiopathy (P = 0.007), BMI value (P = 0.003), left-sided procedure (P = 0.04), tumor stage (P = 0.04), and tumor size (P = 0.002). These differences were overcome by propensity score matching (PSM) analysis that yielded two well-matched groups which included 61 patients in each group. Surgical outcomes including blood loss, hospital stay and complications were similar before and after matching analysis, but SVATS compared to CVATS was associated with longer operative time before (159 ± 13 vs. 126 ± 6.3, P < 0.0001), and after matching analysis (161 ± 23 vs. 119 ± 8.3; P < 0.0001) and significant reduction of postoperative pain during the different time-points (P < 0.001), and paresthesia at one (P = 0.001), and three months (P < 0.0001).

CONCLUSIONS: SVATS lobectomy is a feasible and safe strategy with surgical outcomes similar to CVATS lobectomy but with less postoperative pain and paresthesia.

KEY POINTS: SIGNIFICANT FINDINGS OF THE STUDY: Subxifoid thoracoscopic lobectomy is a feasible and safe procedure, with potential benefits in terms of postoperative pain and paresthesia compared to conventional thoracoscopic lobectomy Our results showed that surgical outcomes including blood loss, hospital stay, morbidity and mortality are similar but subxifoid thoracoscopy was associated with significant reduction of postoperative pain and paresthesia.

WHAT THIS STUDY ADDS: Subxifoid thoracoscopy is a safe procedure; compared to conventional transthoracic thoracoscopy, it avoids intercostal incisions, and spares nerve trauma, resulting in a reduction of postoperative pain and paresthesia.

PMID:33689213 | DOI:10.1111/1759-7714.13778

Reprod Sci. 2021 Mar 10. doi: 10.1007/s43032-021-00532-3. Online ahead of print.

ABSTRACT

Previous studies have reported that the mitochondrial DNA (mtDNA) contents of cumulus cells (CCs) in ovarian follicular fluid are correlated with embryo quality. Quantification of mtDNA CCs has been suggested as a biomarker of embryo viability. The aim of this study was to determine the relationship between mitochondrial DNA (mtDNA)/genomic DNA (gDNA) ratio in CCs and IVF outcomes such as fertilization rates and embryo quality in infertile women. This is an observational study on 144 cumulus-oocyte complexes obtained from 144 patients undergoing IVF-intracytoplasmic sperm injection (ICSI) at a single fertility center. The CCs in ovarian follicular fluid from patients undergoing IVF-ICSI were collected by ovum pick-up. A relative copy number quantification was used to determine mtDNA/gDNA ratio. Quantitative real-time PCR for various markers (β2M and mtMinArc gene) was used to determine average mtDNA/gDNA ratio of CCs. Investigation of the correlation between mtDNA/gDNA ratio in CCs and IVF outcomes showed no statistically significant correlation between the mtDNA/gDNA ratio in CCs and fertilization rates. However, mtDNA/gDNA ratio and embryo quality showed a statistically significant positive correlation. A significantly higher mtDNA/gDNA ratio was observed in the good quality embryo group compared with the poor quality embryo group (P < 0.05). In addition, the mtDNA/gDNA ratio showed negative correlation with the patient’s age (correlation coefficient= -0.228, P < 0.05). Results of this study demonstrate a negative correlation of mtDNA/gDNA ratio in CCs with patient’s age, and a low copy number of mtDNA in CCs may have adverse effects on embryo quality in IVF cycles. These results suggest that the ratio of mtDNA/gDNA in CCs may serve as a biomarker in predicting IVF outcomes.

PMID:33689162 | DOI:10.1007/s43032-021-00532-3

J Periodontol. 2021 Mar 10. doi: 10.1002/JPER.21-0004. Online ahead of print.

ABSTRACT

BACKGROUND: Periodontitis and the Triglyceride/High Density Lipoprotein Cholesterol (TG/HDL-C) ratio have both been associated with cardiovascular disease, metabolic syndrome and obesity. Additionally, the ratio is a possible substitute for predicting insulin resistance. This study investigated the association between periodontitis, its severity levels (exposures), and the TG/HDL-C ratio (outcome).

METHODS: A cross-sectional study of public health service users in Brazil considered socioeconomic-demographic characteristics, lifestyle behavior, and general and oral health conditions. Anthropometric measurements and blood pressure were also measured. Systemic biomarker data were obtained, as well as assessment of periodontal diagnosis and its severity. The TG/HDL-C ratio was calculated using the serum triglyceride level over HDL cholesterol and the cut-off point, TG/HDL-C ≥2.3 serving as the cutoff indicting dyslipidemia. Logistic and linear regression were used to statistically analyze the data.

RESULTS: A total of 1,011 participants were included, with 84.17% having periodontitis and 49.85% having a TG/HDL-C ratio ≥2.3. For individuals with periodontitis, the odds of TG/HDL-C ratio ≥2.3 was 1.47 times greater than in those without periodontitis (OR_Adjusted = 1.47, 95%CI: 1.02-2.14). Similar results were found for those with moderate and severe periodontitis, with a slight increase in the measurement magnitude with disease severity.

CONCLUSION: A positive relationship between periodontitis and the TG/HDL-C ratio ≥2.3 was found, suggesting a possible association with periodontal disease severity. This article is protected by copyright. All rights reserved.

PMID:33689171 | DOI:10.1002/JPER.21-0004

Zoo Biol. 2021 Mar 10. doi: 10.1002/zoo.21597. Online ahead of print.

ABSTRACT

Red pandas (Ailurus fulgens) are small charismatic mammals native across montane southern Asia, now endangered by human impacts. They are considered “living fossils” as the sole member of a distinct family, warranting higher conservation priority. Therefore, ex situ breeding programs were initiated to prevent extinction and act as genetic reservoirs for reintroduction, although complicated by apparent taxonomic subdivision. This study investigated whether the separation of captive red pandas in the North American Species Survival Plan® by putative subspecies was justified. A 383-bp segment of mitochondrial DNA control region was therefore sequenced from 67 members representing matriarchal lineages of both groups. A network analysis placed the 11 haplotypes found into separate but closely connected clusters, with one group more strongly related than the other. Statistical analyses and diversity indices corroborated differentiation between the two management units. Phylogenetic analyses employing multiple outgroups confirmed, although not robustly, reciprocal monophyly of the four- and seven-haplotype clades representing putative subspecies Ailurus fulgens fulgens and Ailurus fulgens styani, respectively. These empirical results are adequate to justify continued independent management of these zoo subpopulations, but cannot be definitive for taxonomic classification due to limited sampling from their native range. They will, however, be useful in evaluating long-term genetic diversity changes, focusing management efforts on newly revealed evolutionary limitations, and comparing with an assessment of wild red pandas to determine how representative zoo populations are for reintroduction purposes. Maintaining genetic diversity and population structure of endangered species is essential to protect evolutionary potential and adaptations for long-term sustainability.

PMID:33689172 | DOI:10.1002/zoo.21597

Cancer Cytopathol. 2021 Mar 10. doi: 10.1002/cncy.22402. Online ahead of print.

ABSTRACT

BACKGROUND: The purpose of this study was to determine the pathological and ultrasound (US) features of benign nonpalpable breast lesions (NPBLs) classified as Breast Imaging Reporting and Data System (BI-RADS) category 4C or 5.

METHODS: Between 2003 and 2007, 849 consecutive NPBLs detected at US and classified as BI-RADS category 4C (505) or 5 (344) initially underwent US-guided fine needle aspiration (FNA) at our institution. Benign diagnoses were established according to surgical excision findings or during a minimal 6-month imaging follow-up (mean, 3.7 years [SD, 2.6 years]). US BI-RADS features were reviewed and compared retrospectively using a chi-square test for the following pathological categories: epithelial and fibrous proliferation (EFP), cystic and papillary lesion (C&P), inflammatory lesion (IL), benign tumor (BT), intramammary lymph node (ILN), intraepithelial proliferative lesion (IPL), and nonspecific morphological alteration (NMA). The performance of FNA in the diagnosis of benignity was assessed.

RESULTS: Of 849 NPBLs, 110 (12.9%) NPBLs were benign: 88 (17.4%) were BI-RADS category 4C, and 22 (6.4%) were BI-RADS category 5. Forty-four (40%) were EFPs, 21 (19%) were C&Ps, 13 (12%) were NMAs, 11 (10%) were ILs, 11 (10%) were BTs, 8 (7%) were IPLs, and 2 (2%) were ILNs. Lesion shape, US pattern distribution, and posterior features showed statistically significant differences between these categories (P < .05): 33 (75%) EFPs exhibited posterior shadowing, 18 (86%) C&Ps were homogenous, 9 (82%) ILs were heterogeneous, 11 (100%) BTs were homogeneous, 9 (82%) BTs were oval, and 6 (75%) IPLs were irregularly shaped. Of the 110 benign NPBLs, FNA diagnosis was falsely positive in 7 (6%), suspicious in 10 (9%), and benign in 90 (82%), and 3 (3%) were inadequate for diagnosis.

CONCLUSION: A diverse array of benign NPBLs can be classified as BI-RADS category 4C or 5 on US, each showing specific imaging presentations.

PMID:33689204 | DOI:10.1002/cncy.22402

Pediatr Radiol. 2021 Mar 10. doi: 10.1007/s00247-021-05009-8. Online ahead of print.

ABSTRACT

BACKGROUND: Abdominopelvic magnetic resonance imaging (MRI) is increasingly being used to evaluate children with abdominal pain suspected of having acute appendicitis. At our institution, these examinations are preliminarily interpreted by radiology residents, especially when performed after hours.

OBJECTIVE: To determine the accuracy of preliminary reports rendered by radiology residents in this setting.

MATERIALS AND METHODS: Three hundred seventy-seven pediatric abdominopelvic MRI examinations were included. The preliminary (resident) and final (attending) radiology reports were coded as diagnosing acute appendicitis or no acute appendicitis. The concordance between resident and attending radiologist interpretations was calculated. Additionally, both resident and attending reports were compared to available surgical pathology or clinical follow-up data.

RESULTS: Overall concordance rate for the diagnosis of acute appendicitis was 97.1%. Concordance for verified cases of acute appendicitis was 93.4%. Concordance rates did not differ by residents’ postgraduate year levels. When compared against surgical pathology or clinical follow-up data, residents demonstrated 91.2% sensitivity and 97.6% specificity. There was no statistically significant difference in the sensitivity or specificity of resident or attending radiologist interpretations.

CONCLUSION: Radiology residents demonstrate high concordance with attending pediatric radiologists in their interpretations of pediatric abdominopelvic MRI for acute appendicitis. The diagnostic performances of residents and attendings were comparable.

PMID:33688988 | DOI:10.1007/s00247-021-05009-8

World J Urol. 2021 Mar 10. doi: 10.1007/s00345-021-03646-0. Online ahead of print.

ABSTRACT

OBJECTIVE: To explore the risk of encrustation and biofilm formation for silicone ureteral stents compared to percuflex polymer stents, through a randomized multicenter study.

PATIENTS AND METHODS: Design, setting and participants: A Multicenter, prospective, randomized, single blind, comparative study of hydrocoated silicone stent (Coloplast Imajin^® hydro) versus Percuflex™ Plus stent (Boston Scientific), in 141 patients treated by flexible URS for a kidney stone. The study had ethical committee approval in the respective hospitals. Outcome measurements and statistical analysis: Endpoints related to encrustation were biofilm formation and mineral encrustation after a period of 3-week indwelling time. They were evaluated at removal through a scoring scale of ureteral stents encrustation, infrared spectroscopy and optical microscopy of inner and outer surfaces of tips, angles and along the stent’s body. Comparison was performed using ANOVA.

RESULTS: 119 stents were available after removal for analysis, 56 in the silicone and 63 in the Percuflex TM Plus group. Mean dwelling duration was 21.8 days for silicone, 22.1 days for PercuflexTM Plus. There was significantly more biofilm on Percuflex™ Plus compared to silicone (1.24 ± 0.08 vs 0.93 ± 0.09, p = 0.0021), and more mineral encrustation (1.22 ± 0.10 vs 0.78 ± 0.11, p = 0.0048), respectively.

CONCLUSIONS: This multicenter randomized study shows that silicone-hydrocoated stents are less prone to encrustation than PercuflexTM Plus after a 3-week dwelling period and confirms the low encrustation potential of silicone.

PMID:33688992 | DOI:10.1007/s00345-021-03646-0

Arch Sex Behav. 2021 Mar 10. doi: 10.1007/s10508-020-01862-0. Online ahead of print.

ABSTRACT

Evidence suggests that sexual minorities (e.g., those identifying as lesbian, gay, or bisexual) experience increased rates of depression compared to heterosexual individuals. Minority stress theory suggests that this disparity is due to stigma experienced by sexual minorities. Stigma processes are proposed to contribute to reduced coping/support resources and increased vulnerability processes for mental health problems. This review provided a systematic examination of research assessing the evidence for mediating factors that help explain such disparities. A literature search was conducted using the databases PubMed, PsycINFO, and Web of Science. The review included 40 identified studies that examined mediators of sexual minority status and depressive outcomes using a between-group design (i.e., heterosexual versus sexual minority participants). Studies of adolescents and adult samples were both included. The most common findings were consistent with the suggestion that stressors such as victimization, harassment, abuse, and increased stress, as well as lower social and family support, may contribute to differing depression rates in sexual minority compared to heterosexual individuals. Differences in psychological processes such as self-esteem and rumination may also play a role but have had insufficient research attention so far. However, caution is needed because many papers had important methodological shortcomings such as the use of cross-sectional designs, inferior statistical analyses for mediation, or measures that had not been properly validated. Although firm conclusions cannot be drawn, the current evidence base highlights many factors potentially suitable for further exploration in high-quality longitudinal research or randomized studies intervening with the potential mediators.

PMID:33689086 | DOI:10.1007/s10508-020-01862-0