Tag: statistics

J Child Lang. 2021 Sep 14:1-13. doi: 10.1017/S0305000921000532. Online ahead of print.

ABSTRACT

Children learn words in ambiguous situations, where multiple objects can potentially be referents for a new word. Yet, researchers debate whether children maintain a single word-object hypothesis – and revise it if falsified by later information – or whether children establish a network of word-object associations whose relative strengths are modulated with experience. To address this issue, we presented 4- to 12-year-old children with sets of mutual exclusivity (fast-mapping) trials: offering them with obvious initial hypotheses (that the novel object is the referent for the novel word). We observe that children aged six years and above, despite showing a novelty bias and retaining this novel word – novel object association, also formed an association between the novel word and the name-known object, thereby suggesting that older children attend to more than one word-object association, in a manner similar to associative learning. We discuss our findings in the context of competing theoretical accounts related to word learning.

PMID:34519266 | DOI:10.1017/S0305000921000532

Eur J Endocrinol. 2021 Sep 1:EJE-21-0351.R2. doi: 10.1530/EJE-21-0351. Online ahead of print.

ABSTRACT

Objective Female patients treated with alkylating agents in childhood are at risk for ovarian impairment. We aimed at describing the pattern of residual ovarian function in a cohort of survivors of hematological malignancies and/or hematopoietic stem cell transplantation (HSCT) and assessing the relationship between Cyclophosphamide Equivalent Dose (CED) and Anti-Müllerian Hormone (AMH). Design and methods Gonadal health was clinically and biochemically assessed in 124 post-menarchal survivors who underwent treatment for pediatric hematological malignancies and/or HSCT between 1992 and 2019. Results Overt “premature ovarian insufficiency” (POI) was detected in 72.1% and 3.7% of transplanted and non-transplanted patients, respectively; milder “diminished ovarian reserve” (DOR) in 16.3% and 22.2%. In non-transplanted patients, increasing CED values were associated with lower AMH-SDS (p 0.04), with the threshold of 7200 g/m2 being the best discriminator between DOR/POI and normal ovarian function (AUC: 0.75 on ROC analysis) and with an observed decrease of 0.14 AMH-SDS for each CED increase of 1 gr/m2. In addition, age at diagnosis ≥10 years played a detrimental role on ovarian reserve (p 0.003). In the HSCT group, irradiation was associated with a statistically significant reduction in AMH-SDS (p 0.04). Conclusions In non-transplanted patients, CED ≥ 7200 mg/m2 was associated with a DOR, while younger age at diagnosis played a protective role on ovarian reserve. As a result of the data collected, we propose a systematic algorithm to assess iatrogenic gonadal impairment in young female patients exposed to chemo-radiotherapy in childhood for hematological disorders.

PMID:34519276 | DOI:10.1530/EJE-21-0351

Cochlear Implants Int. 2021 Sep 14:1-11. doi: 10.1080/14670100.2021.1973208. Online ahead of print.

ABSTRACT

OBJECTIVE: There is still a lack in precise postoperative evaluation of the cochlea because of strong artifacts. This study aimed to improve accuracy of postoperative two-turn (2TL) and cochlear duct length (CDL) measurements by applying flat-panel volume computed tomography (fpVCT), secondary reconstruction (fpVCT_SECO) and three-dimensional curved multiplanar reconstruction.

METHODS: First, 10 temporal bone specimens with or without electrode were measured in multi-slice computed tomography (MSCT), fpVCT and fpVCT_SECO and compared to high-resolution micro-CT scans. Later, pre- and postoperative scans of 10 patients were analyzed in a clinical setting.

RESULTS: Concerning 2TL, no statistically significant difference was observed between implanted fpVCT_SECO and nonimplanted micro-CT in 10 temporal bone specimens. In contrast, there was a significant discrepancy for CDL (difference: -0.7 mm, P = 0.004). Nevertheless, there were no clinically unacceptable errors (±1.5 mm). These results could be confirmed in a clinical setting. Using fpVCT_SECO, CDL was slightly underestimated postoperatively (difference: -0.5 mm, P = 0.002) but without any clinically unacceptable errors.

CONCLUSION: fpVCT_SECO can be successfully applied for a precise measurement of the cochlear lengths pre- and postoperatively. However, users must be aware of a slight systematic underestimation of CDL postoperatively. These results may help to refine electrode selection and frequency mapping.

PMID:34519256 | DOI:10.1080/14670100.2021.1973208

Global Spine J. 2021 Sep 14:21925682211041048. doi: 10.1177/21925682211041048. Online ahead of print.

ABSTRACT

STUDY DESIGN: Retrospective cross-sectional study.

OBJECTIVE: To investigate the prevalence, characteristics, and risk factors of spine-related malpractice claims in China in a 2-year period.

METHODS: The arbitration files of the Chinese Medical Association (CMA) were reviewed for spine-related malpractice claims. Descriptive statistics and correlation analysis were conducted on claim characteristics, clinical data, plaintiff’s main allegations, and arbitration outcomes.

RESULTS: A total of 288 cases of spinal claims filed in the CMA between January 2016 and December 2017 were included. Most claims were found in lumbar degenerative disorders (59.4%), lumbar trauma (13.2%), and cervical degenerative disorders (11.8%). The most common adverse events (AEs) leading to claims were new neurologic deficit (NND) (47.6%), infection (11.5%), and insufficient symptom relief (10.4%). The most common patient allegation was surgical error (66.0%), although the main arbitrated cause of AEs was disease/treatment itself (49.0%), while providers were judged as mainly responsible in only 47.3% cases. In multivariate regression analysis, cervical spine, misdiagnosis/mistreatment, and unpredictable emergency correlated with more severe damage to patients; minimally invasive surgery was predictive of judgment in plaintiff’s favor, while claims in the eastern region and unpredictable emergencies were predictive of defendant’s favor; only NND was associated with being arbitrated as surgical error in surgical cases where surgeons accepted major liability.

CONCLUSION: The current study provided a descriptive overview and risk factor analysis of spine-related malpractice claims in China. Gaining improved understanding of the facts and causes of malpractice claims may help providers reduce the risk of claims and subsequent litigation.

PMID:34519250 | DOI:10.1177/21925682211041048

Global Spine J. 2021 Sep 14:21925682211025501. doi: 10.1177/21925682211025501. Online ahead of print.

ABSTRACT

STUDY DESIGN: Retrospective database study.

OBJECTIVES: To compare the accuracy and safety of 2 types of a computer-assisted navigation system for percutaneous pedicle screw placement during endoscopic lumbar interbody fusion.

METHODS: From May 2019 to January 2020, data of 56 patients who underwent Endo-LIF with a robot-assisted system and with an electromagnetic navigation system were compared. The pedicles in all patients were subjected to postoperative CT scan to assess screw correction by measuring the perpendicular distance between the pedicle cortical wall and the screw surface. The registration and matching time, guide-wire insertion time, the entire surgery time, and X-ray exposure time were recorded.

RESULTS: In the robot-assisted group, 25 cases with 100 percutaneous pedicle screws were included, and the excellent and good rate was 95%. In the electromagnetic navigation group, 31 cases with 124 screws were included, and the excellent rate was 97.6%. There was no statistical difference between the two groups (P > 0.05). The registration time and the total time for the surgery also showed no statistical differences (P > 0.05). The main difference between the two groups was the guide-wire insertion time and the X-ray exposure time (P < 0.05).

CONCLUSIONS: Both electromagnetic navigation and robot-assisted are safe and efficient for percutaneous pedicle screw placement. Electromagnetic navigation system has obvious advantages over robot-assisted in terms of faster guide-wire placement and less X-ray exposure. Robot-assisted for percutaneous pedicle screw placement offers a preoperative planning system and a stable registration system, with obvious drawbacks of a strict training curve.

PMID:34519243 | DOI:10.1177/21925682211025501

Am Surg. 2021 Sep 14:31348211041555. doi: 10.1177/00031348211041555. Online ahead of print.

ABSTRACT

BACKGROUND: Low colorectal anastomoses carry a high anastomotic leak (AL) rate (up to 20%) and thus are commonly diverted. Much less is known about mid-to-high colorectal anastomosis, which carries a leak rate of 2-4%. The objective of this study was to determine our AL rate after mid-to-high colorectal anastomosis and associated risk factors.

METHODS: A single center retrospective cohort study of patients undergoing left colonic resections with mid-to-high colorectal anastomosis (≥7 cm from the anal verge) from January 2008 to October 2017 was utilized. Main outcome, AL, defined as clinical suspicion supported by radiological or intraoperative findings, was calculated and risk factors assessed using multivariable logistic regression analysis.

RESULTS: 977 patients were included; 487 (49.9%) were male, with a mean age of 59.8 (+/-12.1) years. Mean BMI was 27.5 (+/-5.5) kg/m². Diverticular disease (67.5%), malignancy (17.4%), and inflammatory bowel disease (2.2%) were the main indications for resection. Mean length of stay was 6.7 (+/-4.5) days. 455 (46.8%) colonic resections were performed by laparoscopy, 283 (29.1%) by hand assisted surgery, 219 (22.5%) by laparotomy, and 16 (1.6%) by robotics. Majority of patients had complete donuts (99.6%) and a negative air leak test (97.7%). 149 patients (15.3%) underwent construction of a diverting stoma. The overall AL rate was 2.1% (n = 20). Increased BMI (>30 kg/m²), P = .02, was an independent risk factor for AL and a trend observed for positive air leak tests (P = .05), with other factors failing to achieve statistical significance.

CONCLUSIONS: Patients with mid-to-high colorectal anastomosis have a 2% AL risk. Increased BMI was a risk factor for AL.

PMID:34519249 | DOI:10.1177/00031348211041555

Stat Methods Med Res. 2021 Sep 14:9622802211037071. doi: 10.1177/09622802211037071. Online ahead of print.

ABSTRACT

Ultrahigh-dimensional gene features are often collected in modern cancer studies in which the number of gene features $p$ is extremely larger than sample size $n$. While gene expression patterns have been shown to be related to patients’ survival in microarray-based gene expression studies, one has to deal with the challenges of ultrahigh-dimensional genetic predictors for survival predicting and genetic understanding of the disease in precision medicine. The problem becomes more complicated when two types of survival endpoints, distant metastasis-free survival and overall survival, are of interest in the study and outcome data can be subject to semi-competing risks due to the fact that distant metastasis-free survival is possibly censored by overall survival but not vice versa. Our focus in this paper is to extract important features, which have great impacts on both distant metastasis-free survival and overall survival jointly, from massive gene expression data in the semi-competing risks setting. We propose a model-free screening method based on the ranking of the correlation between gene features and the joint survival function of two endpoints. The method accounts for the relationship between two endpoints in a simply defined utility measure that is easy to understand and calculate. We show its favorable theoretical properties such as the sure screening and ranking consistency, and evaluate its finite sample performance through extensive simulation studies. Finally, an application to classifying breast cancer data clearly demonstrates the utility of the proposed method in practice.

PMID:34519231 | DOI:10.1177/09622802211037071

Urologia. 2021 Sep 14:3915603211046161. doi: 10.1177/03915603211046161. Online ahead of print.

ABSTRACT

AIMS: Ureteropelvic junction obstruction (UPJO) may originate from extrinsic or intrinsic causes in children. The aim of this study is to present preoperative and postoperative data of our patients operated for UPJO.

METHODS: A total of 64 patients who underwent open pyeloplasty were investigated retrospectively. They were evaluated in terms of demographically, clinics, hydronephrosis, differential renal functions (DRFs), half-time tracer clearance (½TC), and histopathologic results. Patients’ numerical results were stated as mean ± standard deviation (SD).

RESULTS: Male gender was more prevalent (n = 47, 73.4%) and mean age at surgery was 46.87 months. UPJO was located at the left side in 56.3% (n = 36), and at the right side in 39.1% (n = 25) of patients. It was bilateral in 4.7% (n = 3). Hydronephrosis was found antenatally in 68.8% (n = 44) of patients. The mean preoperative DRF was 49.7% (21-78%) and mean postoperative DRF was 49.2% (20-56%). Mean renal scintigraphic t_1/2 was >20 min for all patients. The mean AP diameter was 21.58 mm (10-62 mm). Muscular hypertrophy was the most common pathological finding, mean length of excised segment was 10.26 mm (3-40 mm). Crossing vessel (CV) was detected in 17.18% (n = 11). The CV was statistically associated with increased age of operation, left side, and female gender. Statistically significant hydronephrosis was found in non-CV patients. Re-operation was required in seven patients (7.8%).

CONCLUSIONS: Intrinsic pathologies are more seen in the etiology of UPJO patients with antenatal diagnosis and this group needs operation at an earlier age. However, CV is found more commonly in patients who are diagnosed and operated at older ages.

PMID:34519240 | DOI:10.1177/03915603211046161

Turk J Med Sci. 2021 Sep 14. doi: 10.3906/sag-2104-138. Online ahead of print.

ABSTRACT

BACKGROUND: The relationship between the activation of the renin-angiotensin system and the increase in erythropoiesis has been shown in many studies. In addition, the use of angiotensin converting enzyme inhibitors or angiotensin-receptor blockers has been reported to reduce hemoglobin levels in various patient groups at risk for secondary erythrocytosis/polycythemia.

AIMS: To investigate whether there is any change in hemoglobin levels after starting ACEI or ARB in patients who have not previously used them.

METHODS: 351 patients who were started on RAAS blockers were evaluated retrospectively. None of the patients had anemia before starting RAAS blockers. A median of 6 (4-12) months after the start of the drug, complete blood count and kidney function tests were evaluated. Hemoglobin values before and after the start of the drug were compared statistically.

RESULTS: A statistically significant decrease in mean Hb value was found after starting ACEI or ARB (14.39±1.29 g/dl vs. 13.98±1.36 g/dl, p<0.001). The decrease in control Hb values was higher in the ARB group than in the ACEI group (-0.53±0.06 g/dl vs -0.29±0.06 g/dl, p<0.001).

CONCLUSIONS: A significant decrease in mean Hb level was detected in the first year following the first administration of ACEIs or ARBs.

PMID:34519192 | DOI:10.3906/sag-2104-138

Drug Deliv. 2021 Dec;28(1):1877-1889. doi: 10.1080/10717544.2021.1974608.

ABSTRACT

Vulvovaginal candidiasis is a pervasive gynecological condition among women worldwide due to infection recurrence and resistance to conventional drugs. This calls for a novel formulation of alternative medication and with enhanced efficacy. This study aimed to fabricate mixed-lipid nanoconstructs (MLNCs) of voriconazole (VCZ) with a low concentration of lipids applying high shear homogenization and ultrasonication to form a semisolid formulation. Tefose 63 and Gelot 64 were employed as emulsifiers that are specified for vaginal preparations; as per their mucoadhesive properties and their texture enhancing characters, although usually used as lipids in different lipid carriers. A 2⁴ factorial design was established and the optimized formulation was prepared using 10% total lipids, in which solid lipids (Sterotex NF: Glyceryl monostearate) ratio was 1.92:1 and the oils percentage was 30% (Maisine: Glyceryl monooleate, in the ratio of 1:1), and the emulsifiers mixture (Tefose 63: Gelot 64) ratio was 1:1, as 10% of total formulation weight. The optimized formulation with a viscosity of 964.49 ± 57.99 cp showed spherical nanoparticles (322.72 ± 15.11 nm) that entrapped 67.16 ± 3.45% of VCZ and exhibited release of 70.08 ± 2.87% in 8 h. The optimized formulation with high bioadhesive potentials significantly reduced the fungal burden in female Wistar rats infected with vaginal candidiasis, compared to the aqueous VCZ suspension (p < .05). Furthermore, in vivo histopathological findings proved the effectiveness and the safety of the optimized MLNCs formulation after vaginal application. Inclusively, MLNCs formulation could be a promising vaginal delivery system of VCZ for the treatment of vulvovaginal candidiasis.

PMID:34519230 | DOI:10.1080/10717544.2021.1974608