Tag: statistics

Biom J. 2023 Mar 31:e2200238. doi: 10.1002/bimj.202200238. Online ahead of print.

ABSTRACT

The constant development of new data analysis methods in many fields of research is accompanied by an increasing awareness that these new methods often perform better in their introductory paper than in subsequent comparison studies conducted by other researchers. We attempt to explain this discrepancy by conducting a systematic experiment that we call “cross-design validation of methods”. In the experiment, we select two methods designed for the same data analysis task, reproduce the results shown in each paper, and then reevaluate each method based on the study design (i.e., datasets, competing methods, and evaluation criteria) that was used to show the abilities of the other method. We conduct the experiment for two data analysis tasks, namely cancer subtyping using multiomic data and differential gene expression analysis. Three of the four methods included in the experiment indeed perform worse when they are evaluated on the new study design, which is mainly caused by the different datasets. Apart from illustrating the many degrees of freedom existing in the assessment of a method and their effect on its performance, our experiment suggests that the performance discrepancies between original and subsequent papers may not only be caused by the nonneutrality of the authors proposing the new method but also by differences regarding the level of expertise and field of application. Authors of new methods should thus focus not only on a transparent and extensive evaluation but also on comprehensive method documentation that enables the correct use of their methods in subsequent studies.

PMID:36999395 | DOI:10.1002/bimj.202200238

Br J Nutr. 2023 Mar 31:1-32. doi: 10.1017/S0007114523000648. Online ahead of print.

ABSTRACT

Sports foods are convenient alternatives to everyday foods to fuel performance. Strong scientific evidence supports their use; however, commercial sports foods are classified by the NOVA system as ultra-processed foods (UPF). Consumption of UPF has been associated with poor mental and physical health, but little is known about athletes’ consumption of and attitudes toward sports foods as a source of UPF. The aim of this cross-sectional study was to assess Australian athletes’ intake of and attitudes toward sports foods and UPF. Adult athletes were recruited to complete an anonymous online survey via social media between October 2021 and February 2022. Data were analysed using descriptive statistics, and Pearson’s chi-square test was used to assess potential relationships between categorical demographic variables and consumption of sports foods. One hundred forty Australian adults participating in recreational (n=55), local/regional (n=52), state (n=11), national (n=14), or international (n=9) sports completed the survey. Ninety-five per cent reported consuming sports foods within the past 12 months. Participants consumed sports drinks most commonly (73%) and isolated protein supplements most frequently (40% at least once per week). Participants reported everyday foods to be more affordable, taste better, present less risk of banned substances, but less convenient, and greater risk of spoilage. Half (51%) of participants reported concern about health effects of UPF. Participants reported regular UPF consumption despite taste and cost-related preferences for everyday foods and health concerns regarding UPF intake. Athletes may need support to identify and access safe, affordable, convenient, minimally processed alternatives to sports foods.

PMID:36999372 | DOI:10.1017/S0007114523000648

Vasc Specialist Int. 2023 Mar 31;39:7. doi: 10.5758/vsi.220060.

ABSTRACT

PURPOSE: This study aimed to report the results of femorofemoral bypass (FFB) using a great saphenous vein (GSV) graft as an alternative to polytetrafluoroethylene (PTFE) grafts.

MATERIALS AND METHODS: From January 2012 to December 2021, 168 patients who underwent FFB (PTFE, 143; GSV, 25) were included. The patients’ demographic features and surgical intervention results were retrospectively reviewed.

RESULTS: There were no intergroup differences in patients’ demographic features. In GSV vs. PTFE grafts, the superficial femoral artery provided statistically significant inflow and outflow (P<0.001 for both), and redo bypass was more common (P=0.021). The mean follow-up duration was 24.7±2.3 months. The primary patency rates at 3 and 5 years were 84% and 74% for PTFE grafts and 82% and 70% for GSV grafts, respectively. There was no significant intergroup difference in primary patency (P=0.661) or clinically driven target lesion revascularization (CD-TLR)-free survival (P=0.758). Clinical characteristics, disease details, and procedures were analyzed as risk factors for graft occlusion. Multivariate analysis revealed that none of the factors was associated with an increased risk of FFB graft occlusion.

CONCLUSION: FFB using PTFE or GSV grafts is a useful method with an approximately 70% 5-year primary patency rate. The GSV and PTFE grafts showed no difference in primary patency or CD-TLR-free survival during follow-up; however, FFB using GSV may be an option in selective situations.

PMID:36999355 | DOI:10.5758/vsi.220060

Res Synth Methods. 2023 Mar 31. doi: 10.1002/jrsm.1634. Online ahead of print.

ABSTRACT

We developed metadta, a flexible, robust and user-friendly statistical procedure that fuses established and innovative statistical methods for meta-analysis, meta-regression, and network meta-analysis of diagnostic test accuracy studies in Stata. Using data from published meta-analyses, we validate metadta by comparing and contrasting its features and output to popular procedures dedicated to the meta-analysis of diagnostic test accuracy studies; (midas (Stata), metandi (Stata), metaDTA (web application), mada (R), and MetaDAS (SAS)). We also demonstrate how to perform network meta-analysis with metadta, for which no alternative procedure is dedicated to network meta-analysis of diagnostic test accuracy data in the frequentist framework. metadta generated consistent estimates in simple and complex diagnostic test accuracy data sets. We expect its availability to stimulate better statistical practice in the evidence synthesis of diagnostic test accuracy studies. This article is protected by copyright. All rights reserved.

PMID:36999350 | DOI:10.1002/jrsm.1634

J Paediatr Child Health. 2023 Mar 31. doi: 10.1111/jpc.16402. Online ahead of print.

ABSTRACT

AIM: Neuropathic bladder dysfunction (NBD) or neurogenic lower urinary tract dysfunction occurs as a result of a lesion at any level of central nervous system. The most common aetiology of NBD in children is abnormal development of spinal column. These defects cause neurogenic detrusor overactivity which contributes to detrusor-sphincter dysfunction and results in lower urinary tract symptoms such as incontinence. One of the more progressive and insidious, at the same time preventable result of neuropathic bladder is upper urinary tract deterioration. It is vital to aim reduction in bladder pressures and the minimisation of urine stasis in order to prevent or at least attenuate renal disease. Despite world-wide strategies for prevention of neural tube defects currently, we will still be involved in the care of spina bifida patients born every year with a neuropathic bladder and at risk of long-term renal damage. This study was planned for evaluation of results and detection of possible risk factors for upper urinary tract deterioration during routine visits of neuropathic bladder population.

METHODS: The electronic medical records of the patients who were followed up for at least 1 year with the diagnosis of neuropathic bladder in Pediatric Urology and Nephrology units of Adana City Training and Research Hospital were reviewed retrospectively. A total of 117 patients, whose blood, urine, imaging and urodynamic study required for the evaluation of nephrological and urological status were completed and included in the study. Patients under the age of one were excluded from the study. Demographic characteristics, medical history, laboratory and imaging results were recorded. All statistical analyses were analysed by SPSS version 21 software package and analysed by descriptive statistical.

RESULTS: Of the 117 patients who participated in the study, 73 (62.4%) were female and 44 (37.6%) were male. Mean age of the patients was 6.7 ± 4.9 years. The leading cause of neuropathic bladder was neuro-spinal dysraphism with 103 (88.1%) patients. Urinary tract ultrasound imaging revealed hydronephrosis in 44 patients (35.9%), parenchymal thinning in 20 patients (17.1%), increased parenchymal echo in 20 patients (17.1%) and trabeculation or increase in wall thickness of the bladder in 51 patients (43.6%). Voiding cystogram revealed the presence of vesicoureteral reflux in a total of 37 patients (31.6%), with 28 patients being unilateral and 9 patients bilateral. More than half of the patients had abnormal bladder findings (52.1%). In the Tc 99 m DMSA scan of the patients, 24 patients (20.5%) had unilateral renal scars and 15 (12.8%) had bilateral. Loss of renal function was detected in 27 (23.1%) of the patients. Urodynamic study revealed decreased bladder capacity in 65 patients (55.6%) and increased detrusor leakage pressure was found in 60 patients (51.3%). The mean leak point pressure of the patients was 36 ± 26 cm H₂ O, and the mean leakage volume was determined as 157 ± 118 mL.

CONCLUSION: Findings obtained from imaging and urodynamic studies during routine investigation of neuropathic bladder patients can be a guide for the upper urinary tract. According to our results, age, bladder changes in ultrasound and voiding cystogram, high leak point pressure obtained during urodynamic studies are thought to have strong correlation with upper urinary tract damage. The prevalence of progressive chronic kidney disease in children and adults with spina bifida is remarkable and completely preventable. The strategies for prevention of renal disease in this patient population should be planned by coordinated work of urologist with nephrologist and requires family cooperation.

PMID:36999336 | DOI:10.1111/jpc.16402

Turk Kardiyol Dern Ars. 2023 Apr;51(3):163-167. doi: 10.5543/tkda.2023.70337.

ABSTRACT

OBJECTIVE: Down syndrome is a genetic syndrome characterized with various dysmorphisms and congenital malformations such as congenital heart diseases. We aimed to evaluate the relationship between Down syndrome, hypothyroidism, and cardiac ���ndings.

METHODS: Thyroid hormone pro���les and echocardiographic ���ndings were evaluated. Patients with hypothyroidism and Down syndrome were named group 1; patients with hypothyroidism without Down syndrome group 2 and group 3 was control. The echocardiographic parameters (interventricular septum and left ventricular systolic, diastolic posterior wall thickness, left ventricular end-diastolic diameter, ejection fraction) were indexed to body surface area. Left ventricular mass index and relative wall thickness were calculated. Patients with relative wall thickness equal to or below 0.42 were classi���ed as eccentric hypertrophy or normal geometry, while those over 0.42 as concentric remodeling or concentric hypertrophy.

RESULTS: Thyroid stimulating hormone values of groups 1 and 2 were signi���cantly higher than those of group 3. There were no signi���cant di���erences for fT4 between the groups. Interventricular septum and left ventricular posterior wall end-diastolic and end-systolic thickness were signi���cantly higher in group 1 than groups 2 and 3. There was no statistically signi���cant di���erence in left ventricular mass index between groups 1 and 2. In terms of relative wall thickness, 16 out of 29 patients in group 1 were revealed as concentric remodeling, 12 as normal geometry, 1 patient as eccentric hypertrophy. In group 2, 6 patients were revealed as concentric remodeling, 14 as normal geometry. There was no statistically signi���cant di���erence of left ventricular end-diastolic thickness between 3 groups.

CONCLUSION: Cardiac morphology and functions were signi���cantly a���ected by hypothyroidism in patients with Down syndrome. Hypertrophy in Down syndrome may be caused by the cellular changes in myocardium.

PMID:36999332 | DOI:10.5543/tkda.2023.70337

Turk Kardiyol Dern Ars. 2023 Apr;51(3):196-201. doi: 10.5543/tkda.2022.37011.

ABSTRACT

OBJECTIVE: Oxidative stress is closely related to the development of atherosclerosis and acute coronary syndromes. In this study, we aimed to examine the relationship between hemogram indices and oxidative stress parameters in patients with ST-segment elevation myocardial infarction.

METHODS: A single-centered, prospective, and cross-sectional study was performed in 61 patients with ST-segment elevation myocardial infarction. Before coronary angiography, in the blood samples taken from the peripheral vein, hemogram indices and oxidative stress parameters such as total oxidative status, total antioxidant status, and oxidative stress index were examined. We examined a total of 15 hemogram indices.

RESULTS: Most of the study patients were male (78%), and the mean age was 59.3 �� 12.2 years. Mean corpuscular volume value was found to be negatively and moderately signi���cantly correlated with total oxidative status and oxidative stress index values (r = ���0.438, r = ���0.490, P <��0.001). A negative and moderate signi���cant correlation was found between mean corpuscular hemoglobin and total oxidative status and oxidative stress index values (r = ���0.487, r = ���0.433, P < 0.001). Red cell distribution width value was found to be positively and moderately correlated with total oxidative status (r = 0.537, P < 0.001). Red cell distribution width was also found to be moderately and statistically signi���cantly correlated with oxidative stress index value (r = 0.410, P = 0.001). In receiver operating characteristic analysis, mean corpuscular volume, mean corpuscular hemoglobin, and red cell distribution width levels have been successful in predicting total oxidative status and oxidative stress index.

CONCLUSIONS: We conclude that mean corpuscular volume, mean corpuscular hemoglobin, and red cell distribution width levels predict oxidative stress in patients with ST-segment elevation myocardial infarction.

PMID:36999329 | DOI:10.5543/tkda.2022.37011

Womens Health (Lond). 2023 Jan-Dec;19:17455057231161479. doi: 10.1177/17455057231161479.

ABSTRACT

BACKGROUND: A high proportion of unwanted or unplanned pregnancies may be alcohol-exposed due to contraception failure or non-use. Nevertheless, data on contraception and alcohol use in the context of the risk of alcohol-exposed pregnancies are sparse.

OBJECTIVES: To describe contraception use and alcohol consumption in sexually active non-pregnant women and investigate the factors associated with less effective contraception methods.

STUDY DESIGN: A cross-sectional national survey of women aged 18-35 years.

METHODS: Data from non-pregnant women who were sexually active (n = 517) were analysed. Descriptive statistics were used to report demographics, consumption, and contraception measures. Logistic regression was used to investigate the factors associated with less effective contraception among drinkers.

RESULTS: The majority of participants were younger (46%), of NZ European ethnicity (78%), not in a permanent relationship (54%), with some or completed tertiary education (79%), employed (81%) and not users of the community services card (82%). Twenty-five percent of women were smokers, 94% consumed alcohol, and 72% binged at least ‘monthly or less’. Most women used the pill (56%), and 20% of drinking women were using a contraception method with a 10% or more annual failure rate after 1 year of use. Women who binged ‘weekly or more often’ had similar odds of using less effective contraception as women who ‘never’ binged (p > 0.05). Younger Māori or Pacific women (odds ratio = 5.99; 95% confidence interval of odds 1.15–31.2; p = 0.033) and women who had no tertiary education (odds ratio = 1.75; 95% confidence interval of odds 0.00–3.06; p = 0.052) had higher odds of using less effective contraception.

CONCLUSION: With 20% of women at risk of an alcohol-exposed pregnancy, public health measures to address alcohol consumption and the effective use of contraception are critical to reducing the risk for alcohol-exposed pregnancies in NZ.

PMID:36999316 | DOI:10.1177/17455057231161479

Womens Health (Lond). 2023 Jan-Dec;19:17455057231160955. doi: 10.1177/17455057231160955.

ABSTRACT

BACKGROUND: Midlife peri-menopausal and post-menopausal women with metabolic syndrome experience multiple co-occurring symptoms or symptom clusters, which often result in significant symptom cluster burden. While they are a high-risk symptom burden group, there are no studies that have focused on identifying symptom cluster trajectories in midlife peri-menopausal and post-menopausal women with metabolic syndrome.

OBJECTIVES: The objectives were to identify meaningful subgroups of midlife peri-menopausal and post-menopausal women with metabolic syndrome based on their distinct symptom cluster burden trajectories, and to describe the demographic, social, and clinical characteristics of different symptom cluster burden subgroups.

DESIGN: This is a secondary data analysis using the longitudinal data from Study of Women’s Health Across the Nation.

METHODS: Multi-trajectory analysis using latent class growth analysis was conducted to join the different developmental trajectories of symptom clusters to identify meaningful subgroups and high-risk subgroup for greater symptom cluster burden over time. Then, descriptive statistics were used to explain the demographic characteristics of each symptom cluster trajectory subgroup, and bivariate analysis to examine the association between each symptom cluster trajectory subgroup and demographic characteristics.

RESULTS: A total of four classes were identified: Class 1 (low symptom cluster burden), Classes 2 and 3 (moderate symptom cluster burden), and Class 4 (high symptom cluster burden). Social support was a significant predictor of high symptom cluster burden subgroup and highlights the need to provide routine assessment.

CONCLUSION: An understanding and appreciation for the different symptom cluster trajectory subgroups and their dynamic nature will assist clinicians to offer targeted and routine symptom cluster assessment and management in clinical settings.

PMID:36999312 | DOI:10.1177/17455057231160955

Ugeskr Laeger. 2023 Mar 13;185(11):V09220545.

ABSTRACT

High-prevalence rates and increased morbidity suggest that loneliness is a major public health concern warranting novel health-care strategies and interventions promoting social connectedness. Social prescribing (SP) constitutes such strategy and is, despite scarce evidence, increasingly promoted. Focusing primarily on building and maintaining social support, SP appears especially relevant in connection to community-based physical activity. In this review, we introduce and discuss the adaptation of SP in the context of the Danish healthcare system and provide examples of current research initiatives.

PMID:36999284