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Nevin Manimala Statistics

Bayesian two-stage design for phase II oncology trials with binary endpoint

Stat Med. 2022 Feb 17. doi: 10.1002/sim.9355. Online ahead of print.

ABSTRACT

In phase II oncology trials, two-stage design allowing early stopping for futility and/or efficacy is frequently used. However, this design based on frequentist statistical approaches could not guarantee a high posterior probability of attending the pre-specified clinically interesting rate from a Bayesian perspective. Here, we proposed a new Bayesian design enabling early terminating for efficacy as well as futility. In addition to the clinically uninteresting and interesting response rate, a prior distribution of response rate, the minimum posterior threshold probabilities and the lengths of the highest posterior density intervals were specified in the design. Finally, we defined the feasible design with the highest total effective predictive probability. We studied the properties of the proposed design and applied it to an oncology trial as an example. The proposed design ensured that the observed response rate fell within prespecified levels of posterior probability. The proposed design provides an alternative design to single-arm two-stage trials.

PMID:35178729 | DOI:10.1002/sim.9355

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Nevin Manimala Statistics

Cycle threshold responses in SARS-COV2 PCR tests depend on the method by which the samples were obtained and require strict global standardization

Infection. 2022 Feb 17. doi: 10.1007/s15010-022-01772-4. Online ahead of print.

ABSTRACT

PURPOSE: Since 2020, a SARS-COV2 epidemic has been raging worldwide. The cycle of the PCR test in which the virus is detected is called cycle threshold (CT). The method of obtaining the sample is not detailed in any published study and is based on general guidelines of the CDC. Our contention is that the manner in which the sample is obtained has a dramatic effect on CT values.

METHODS: For each person suspected of having Covid-19 who arrives at the emergency room, two swabs are taken in succession, one according to CDC guidelines and the other according to “Ziv” guidelines. The Ziv method sample collection guidelines determine the depth of penetration, the number of rotations of the swab, and their direction. Each double sample was sent for analysis.

RESULTS: Analysis of the CT results of the sample to results methods and of the Seegene platform clearly found (p = 0.003 and p = 0.001, respectively) that more rigorous sample collection yielded lower CT values.

CONCLUSION: The method of obtaining the samples had a dramatic effect on CT results. Any publication that includes CT results, and certainly studies that discuss CT kinetics, must describe in detail the method by which the samples were obtained. In places where it is also important to detect the onset of illness (airports, hospitals, schools, etc.), it is important to use the Ziv method to reduce the risk of false negatives.

PMID:35178676 | DOI:10.1007/s15010-022-01772-4

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Nevin Manimala Statistics

The generalized Fisher’s combination and accurate p-value calculation under dependence

Biometrics. 2022 Feb 18. doi: 10.1111/biom.13634. Online ahead of print.

ABSTRACT

Combining dependent tests of significance has broad applications but the related p-value calculation is challenging. For Fisher’s combination test, current p-value calculation methods (e.g., Brown’s approximation) tend to inflate the type I error rate when the desired significance level is substantially less than 0.05. The problem could lead to significant false discoveries in big data analyses. This paper provides two main contributions. First, it presents a general family of Fisher type statistics, referred to as the GFisher, which covers many classic statistics, such as Fisher’s combination, Good’s statistic, Lancaster’s statistic, weighted Z-score combination, etc. The GFisher allows a flexible weighting scheme, as well as an omnibus procedure that automatically adapts proper weights and the statistic-defining parameters to a given data. Second, the paper presents several new p-value calculation methods based on two novel ideas: moment-ratio matching and joint-distribution surrogating. Systematic simulations show that the new calculation methods are more accurate under multivariate Gaussian, and more robust under the generalized linear model and the multivariate t-distribution. The applications of the GFisher and the new p-value calculation methods are demonstrated by a gene-based SNP-set association study. Relevant computation has been implemented to an R package GFisher available on the Comprehensive R Archive Network. This article is protected by copyright. All rights reserved.

PMID:35178716 | DOI:10.1111/biom.13634

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Nevin Manimala Statistics

Motor performance of children with attention deficit hyperactivity disorder: focus on the Bruininks-Oseretsky Test of Motor Proficiency

Clin Exp Pediatr. 2022 Feb 17. doi: 10.3345/cep.2021.00962. Online ahead of print.

ABSTRACT

The literature review aimed to analyze studies assessing the motor abilities of children with attention deficit hyperactivity disorder (ADHD) using the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP). The PubMed, OVID, Cochrane, and PEDro databases were searched for relevant articles published between February 2003 and September 2021. Despite the retrieval of limited studies, most included in this review were of fair to good quality. The diagnostic criteria for ADHD adhered to Diagnostic and Statistical Manual of Mental Disorders standards. The BOTMP has been used diversely in various countries, has been translated into various languages, is administered by various qualified medical professionals on children with variants of ADHD, with the long form of the tool used more widely than its short form. The motor performance of children with ADHD was better than that of children with other developmental disorders, but children with ADHD underperformed compared to their age-matched typically developing peers. Although the BOTMP tool has been widely used to evaluate the motor performance of children with various disabilities, our understanding of the motor repertoire of children with ADHD is inadequate. Future research can aim to use the BOTMP to better understand the motor repertoire of children with ADHD to aid their overall rehabilitation.

PMID:35176833 | DOI:10.3345/cep.2021.00962

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Nevin Manimala Statistics

Comparison of clinical efficacy and quality of life between uncut Roux-en-Y and Billroth II with Braun anastomosis in laparoscopic distal gastrectomy for gastric cancer

Zhonghua Wei Chang Wai Ke Za Zhi. 2022 Feb 25;25(2):166-172. doi: 10.3760/cma.j.cn441530-20210702-00257.

ABSTRACT

Objective: To compare the clinical efficacy and quality of life between uncut Roux-en-Y and Billroth II with Braun anastomosis in laparoscopic distal gastrectomy for gastric cancer patients. Methods: A retrospective cohort study was performed. Inclusion criteria: (1) 18 to 75 years old; (2) gastric cancer proved by preoperative gastroscopy, CT and pathological results and tumor was suitable for D2 radical distal gastrectomy; (3) postoperative pathological diagnosis stage was T1-4aN0-3M0 (according to the AJCC-7th TNM tumor stage), and the margin was negative; (4) Eastern Cooperative Oncology Group (ECOG) physical status score <2 points, and American Association of Anesthesiologists (ASA) grade 1 to 3; (5) no mental illness; (6) able to answer questionnaires independently; (7) patients agreed to undergo laparoscopic distal gastrectomy and signed an informed consent. Exclusion criteria: (1) patients with severe chronic diseases and American Association of Anesthesiologists (ASA) grade >3; (2) patients with other malignant tumors; (3) patients suffered from serious mental diseases; (4) patients received neoadjuvant chemotherapy or immunotherapy. According to the above criteria, clinical data of 200 patients who underwent laparoscopic distal gastrectomy at the Department of General Surgery of the First Affiliated Hospital of Army Medical University from January 2016 to December 2019 were collected. Of the 200 patients, 108 underwent uncut Roux-en-Y anastomosis and 92 underwent Billroth II with Braun anastomosis. The general data, intraoperative and postoperative conditions, complications, and endoscopic evaluation 1 year after the surgery were compared. Besides, the quality of life of two groups was also compared using the Chinese version of the European Organization For Research and Treatment of Cancer (EORTC) quality of life questionnaire-Core 30 (QLQ-C30) and quality of life questionnaire-stomach 22 (QLQ-STO22). Results: There were no significant differences in baseline data between the two groups (all P>0.05). All the 200 patients successfully underwent laparoscopic distal gastrectomy without intraoperative complications, conversion to open surgery or perioperative death. There were no significant differences between two groups in operative time, intraoperative blood loss, postoperative complications, time to flatus, time to removal of gastric tube, time to liquid diet, time to removal of drainage tube or length of postoperative hospital stay (all P>0.05). Endoscopic evaluation was conducted 1 year after surgery. Compared to Billroth II with Braun group, the uncut Roux-en-Y group had a significantly lower incidences of gastric stasis [19.8% (17/86) vs. 37.0% (27/73), χ(2)=11.199, P=0.024], gastritis [11.6% (10/86) vs. 34.2% (25/73), χ(2)=20.892, P<0.001] and bile reflux [1.2% (1/86) vs. 28.8% (21/73), χ(2)=25.237, P<0.001], and the differences were statistically significant. The EORTC questionnaire was performed 1 year after surgery, there were no significant differences in the scores of QLQ-C30 scale between the two groups (all P>0.05), while the scores of QLQ-STO22 showed that, compared to the Billroth II with Braun group, the uncut Roux-en-Y group had a lower pain score (median: 8.3 vs. 16.7, Z=-2.342, P=0.019) and reflux score (median: 0 vs 5.6, Z=-2.284, P=0.022), and the differences were statistically significant (all P<0.05), indicating milder symptoms. Conclusion: The uncut Roux-en-Y anastomosis is safe and reliable in laparoscopic distal gastrectomy, which can reduce the incidences of gastric stasis, gastritis and bile reflux, and improve the quality of life of patients after surgery.

PMID:35176829 | DOI:10.3760/cma.j.cn441530-20210702-00257

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Nevin Manimala Statistics

A comparative study on short-term outcomes and quality of life for gastric cancer patients between totally laparoscopic total gastrectomy using an endoscopic linear stapler and laparoscopic-assisted total gastrectomy using a circular stapler

Zhonghua Wei Chang Wai Ke Za Zhi. 2022 Feb 25;25(2):157-165. doi: 10.3760/cma.j.cn441530-20210430-00185.

ABSTRACT

Objective: To explore the differences of short-term outcomes and quality of life (QoL) for gastric cancer patients between totally laparoscopic total gastrectomy using an endoscopic linear stapler and laparoscopic-assisted total gastrectomy using a circular stapler. Methods: A retrospective cohort study was conducted. Clinicopathological data of patients with stage I to III gastric adenocarcinoma who underwent laparoscopic total gastrectomy from January 2017 to January 2020 were retrospectively collected. Those who were ≥80 years old, had serious complications that could affect the quality of life, underwent multi-organ resections, palliative surgery, emergency surgery due to gastrointestinal perforation, obstruction, bleeding, died or lost to follow-up within 1 year after surgery were excluded. A total of 130 patients were enrolled and divided into circular stapler group (CS group, 77 cases) and linear stapler group (LS group, 53 cases) according to the surgical method. The differences of age, gender, body mass index, number of comorbidities, history of abdominal surgery, ASA, tumor location, degree of differentiation, tumor length, tumor T stage, tumor N stage, tumor pathological stage and preoperative quality of life between the two groups were not statistically significant (all P>0.05). The observation indicators: (1) Surgery and postoperative conditions. (2) Postoperative complications: Any adverse conditions that require conservative treatment or surgical intervention after surgery were defined as postoperative complications, of which, complications occurring within 30 days after surgery were defined as early complications; complications occurring within 30 days to 1 year after surgery were defined as late complications. (3) Postoperative quality of life was assessed by the quality of life core scale (QLQ-C30) and gastric cancer specific module scale (QLQ-STO22). The higher the scores of functional scales and global health status, the better the corresponding quality of life. The higher the scores of symptoms scales, the worse the corresponding quality of life. Results: (1) Surgery and postoperative conditions: Compared with the CS group, the LS group presented less intraoperative blood loss [50.0 (50.0-100.0) ml vs. 100.0 (100.0-100.0) ml, Z=-3.111, P=0.002] and earlier time to flatus [(3.1±0.8) days vs. (3.5±1.1) days, t=-2.490, P=0.014]. However, there were no statistically significant differences between two groups of patients in terms of operation time, time to start a liquid diet and postoperative hospital stay (all P>0.05). (2) Postoperative complications: The early complication rates of the CS group and the LS group were 22.1% (17/77) and 18.9% (10/53), respectively, while the late complication rate were 18.2% (14/77) and 15.1% (8/53), respectively, whose differences were not statistically significant (all P>0.05). (3) Postoperative quality of life: After 1-year follow-up, 7 (5.4%) patients were lost, including 5 in CS group and 2 in LS group. One year after operation, the QLQ-C30 scale showed that the score of financial difficulty of the LS group was significantly higher than that of the CS group [33.3 (0 to 33.3) vs.0 (0 to 33.3), Z=-1.972, P=0.049] with statistically significant difference, and there were no statistically significant differences in the scores of other functional fields and symptom fields between the two groups (all P>0.05). The QLQ-STO22 scale showed that the scores of dysphagia [0 (0 to 5.6) vs. 0 (0 to 11.1), Z=-2.094, P=0.036] and eating restriction were significantly lower [0 (0 to 4.2) vs. 0 (0 to 8.3), Z=-2.011, P=0.044] in patients of the LS group than those of the CS group. There were no significant differences in scores of other symptoms between two groups (all P>0.05). Conclusions: Compared with the circular stapler, the esophagojejunostomy with linear stapler for gastric cancer patients can reduce intraoperative blood loss, shorten the time to flatus after operation, alleviate the symptoms of dysphagia and eating restriction but increase the economic burden to a certain degree.

PMID:35176828 | DOI:10.3760/cma.j.cn441530-20210430-00185

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Nevin Manimala Statistics

Common scale minimal sufficient balance: An improved method for covariate-adaptive randomization based on the Wilcoxon-Mann-Whitney odds ratio statistic

Stat Med. 2022 Feb 17. doi: 10.1002/sim.9332. Online ahead of print.

ABSTRACT

Minimal sufficient balance (MSB) is a recently suggested method for adaptively controlling covariate imbalance in randomized controlled trials in a manner which reduces the impact on randomness of allocation over other approaches by only intervening when the imbalance is sufficiently significant. Despite its improvements, the approach is unable to consider the relative clinical importance or magnitude of imbalance in each covariate weight, and ignores any imbalance which is not statistically significant, even when these imbalances may collectively justify intervention. We propose the common scale MSB (CS-MSB) method which addresses these limitations, and present simulation studies comparing our proposed method to MSB. We demonstrate that CS-MSB requires less intervention than MSB to achieve the same level of covariate balance, and does not adversely impact either statistical power or Type-I error.

PMID:35176811 | DOI:10.1002/sim.9332

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Nevin Manimala Statistics

The Frequency Characteristic of Silicone Domes in Receiver in the Canal Hearing Aids

J Am Acad Audiol. 2021 Oct;32(9):556-561. doi: 10.1055/s-0041-1732439. Epub 2022 Feb 17.

ABSTRACT

BACKGROUND: There are several types of silicone domes in receiver in the canal hearing aids (RICs), which have different occlusion levels. However, the frequency characteristics of each type of silicone dome are unclear.

PURPOSE: This study aimed to determine the frequency characteristics of three types of silicone domes (open domes, double-type power domes, and tulip domes) in RICs.

RESEARCH DESIGN: This is an interventional study.

STUDY SAMPLE: In total, 11 participants with a normal sense of hearing were prospectively enrolled.

INTERVENTION: Participants were fitted with hearing aids, which were adjusted to similar settings, and only the silicone domes were changed. The acoustic gain of hearing aids was adjusted to 20 dB in the range of 250 Hz to 4 kHz using the 2-cc coupler.

DATA COLLECTION AND ANALYSIS: We measured the real-ear aided gain (REAG) for each type of silicone dome. In each frequency, we statistically compared the REAG of each type of dome. Acoustic gain using the Open Fit coupler of each type of dome was also measured.

RESULTS: The REAG was obtained with no leakage with open domes only at 2 kHz, and with tulip domes and double-type power domes in the range of 1 to 2 kHz. Double-type power domes obtained significantly higher REAG than tulip domes at 250 and 500 Hz. Under the Open Fit coupler, all types obtained higher acoustic gain than the REAG.

CONCLUSION: This study provides the analysis of the frequency characteristics of silicone domes in RICs. The highest degree of occlusion was observed in double-type power domes, followed by tulip domes, and the lowest was observed in open domes.

PMID:35176798 | DOI:10.1055/s-0041-1732439

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Nevin Manimala Statistics

Electrocochleography and Auditory Brainstem Responses in Persons with Non-Optimal Blood Pressure

J Am Acad Audiol. 2021 Oct;32(9):576-587. doi: 10.1055/s-0041-1733970. Epub 2022 Feb 17.

ABSTRACT

BACKGROUND: Numerous cardiometabolic factors may underlie risk of hearing loss. Modifiable risk factors such as non-optimal blood pressure (BP) are of interest.

PURPOSE: To investigate early auditory evoked potentials (AEPs) in persons with nonoptimal BP.

RESEARCH DESIGN: A cross-sectional nonexperimental study was performed.

STUDY SAMPLE: Fifty-two adults (18-55 years) served as subjects. Individuals were classified as having optimal (systolic [S] BP < 120 and diastolic [D] BP < 80 mm Hg, n = 25) or non-optimal BP (SBP ≥=120 or DBP ≥=80 mm Hg or antihypertensive use, n = 27). Thirteen subjects had hypertension (HTN) (SBP ≥130 or DBP ≥80 mm Hg or use of antihypertensives).

DATA COLLECTION AND ANALYSIS: Behavioral thresholds from 0.25 to 16 kHz were collected. Threshold auditory brain stem responses (ABRs) were recorded using rarefaction clicks (17.7/second) from 80 dB nHL to wave V threshold. Electrocochleograms were obtained with 90 dB nHL 7.1/second alternating clicks and assessed for summating and compound action potentials (APs). Outcomes were compared via independent samples t tests. Linear mixed effects models for behavioral thresholds and ABR wave latencies were constructed to account for potential confounders.

RESULTS: Wave I and III latencies were comparable between optimal and non-optimal BP groups. Wave I was prolonged in hypertensive versus optimal BP subjects at stimulus level 70 dB nHL (p = 0.016). ABR wave V latencies were prolonged in non-optimal BP at stimulus level 80 dB nHL (p = 0.048) and in HTN at levels of 80, 50, and 30 dB nHL (all p < 0.050). DBP was significantly correlated with wave V latency (r = 0.295; p = 0.039). No differences in ABR amplitudes were observed between optimal and non-optimal BP subjects. Electrocochleographic study showed statistically comparable action and summating potential amplitudes between optimal and non-optimal BP subjects. AP latencies were also similar between the groups. Analysis using a set baseline amplitude of 0 μV showed that hypertensive subjects had higher summating (p = 0.038) and AP (p = 0.047) amplitudes versus optimal BP subjects; AP latencies were comparable.

CONCLUSION: Elevated BP and more specifically, HTN was associated with subtle AEP abnormalities. This study provides preliminary evidence that nonoptimal BP, and more specifically HTN, may be related to auditory neural dysfunction; larger confirmatory studies are warranted.

PMID:35176801 | DOI:10.1055/s-0041-1733970

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Nevin Manimala Statistics

HIV First Diagnoses in Germany in 2014 – A Regional Analysis

Gesundheitswesen. 2022 Feb 17. doi: 10.1055/a-1665-6762. Online ahead of print.

ABSTRACT

BACKGROUND: Information on testing units in health care is scarce, particularly the group of late-presenters among the HIV-first diagnoses is still a challenge in Germany.

AIM: Analysis of the impact of testing units on and reasons for the prevalence of HIV-first diagnoses and late presentation, taking 2014 for illustrative purposes.

MATERIAL AND METHODS: Cross-sectional analysis of all individuals, treated in the Network HIV-Regional who were first diagnosed with HIV in 2014; patient characteristics, demographic and clinical data, including information on HIV testing were collected retrospectively and in a decentralised manner, pseudonymized and statistically evaluated.

RESULTS: A total of 971 individuals with HIV-first diagnosis from 31 specialised care centres throughout Germany (15 hospitals, 16 private practices) represented 27.5% of all National HIV-first diagnoses -registrations from Robert Koch Institute for 2014, with similar results for CD4-cell count and HIV-transmission risk. The most common test site was a hospital (34.8%), followed by the office of a family doctor (19.6%) and medical specialist (16.1%). If the first diagnosis was established in hospital, then the patients were on average older than those tested on an ambulant care basis (42 vs. 37 years, p=0.001); moreover, the HI-viral load was higher (585 vs. 270 thousand copies/mL, p<0.001) and the CD4-cell count lower (265 vs. 414/µL, p<0.001). In 208/971 individuals with first diagnosis, at least one AIDS-defining disease was found, most frequently pneumocystis-pneumonia (43.8%), candidiasis (36.5%) and Kaposi sarcoma (10.6%). A regional comparison revealed that in eastern Germany, for first diagnosed HIV-patients were younger, had a higher HIV-RNA viral load and also more often clinical AIDS.

CONCLUSION: This analysis of HIV-Regional for 2014 enables a deeper insight into HIV first diagnoses, on the eve of the introduction of important prevention tools in Germany, e. g., HIV home testing and pre-exposure prophylaxis. This cross-sectional analysis was representative for Germany and underscores the importance of specialised hospitals, in particular for eastern Germany, and furthermore the involvement of late-presenters into HIV health care.

PMID:35176792 | DOI:10.1055/a-1665-6762