Tag: statistics

Genet Epidemiol. 2021 Jul 5. doi: 10.1002/gepi.22422. Online ahead of print.

ABSTRACT

The X-chromosome is often excluded from genome-wide association studies because of analytical challenges. Some of the problems, such as the random, skewed, or no X-inactivation model uncertainty, have been investigated. Other considerations have received little to no attention, such as the value in considering nonadditive and gene-sex interaction effects, and the inferential consequence of choosing different baseline alleles (i.e., the reference vs. the alternative allele). Here we propose a unified and flexible regression-based association test for X-chromosomal variants. We provide theoretical justifications for its robustness in the presence of various model uncertainties, as well as for its improved power when compared with the existing approaches under certain scenarios. For completeness, we also revisit the autosomes and show that the proposed framework leads to a more robust approach than the standard method. Finally, we provide supporting evidence by revisiting several published association studies. Supporting Information for this article are available online.

PMID:34224641 | DOI:10.1002/gepi.22422

Clin Respir J. 2021 Jul 5. doi: 10.1111/crj.13418. Online ahead of print.

ABSTRACT

INTRODUCTION: Asthma is prevalent among children and adolescents. Few studies have assessed the knowledge and perceptions of asthma among adolescents.

OBJECTIVES: This study assessed the knowledge and perception about asthma among secondary school students in an all-girls school in Nigeria.

METHODS: This cross-sectional study was conducted in a Nigerian secondary school in Enugu State (February 2020). In Senior Secondary School (SS1, SS2, SS3), students could be in one of three specialized classes: Sciences, Humanities, Business. A self-administered structured questionnaire was filled by conveniently sampled students in SS1 and SS2. Inferential statistics utilized the Pearson’s Chi-Square test and multiple linear regression with statistical significance set as P < 0.05.

RESULTS: Three hundred and eighty-eight (388) students participated in the study (mean age = 14.64 ± 0.93 years). Majority of the students were in Science class (n = 299; 77.1%). There was high awareness about asthma (n = 384; 99.0%). More than half of them had good asthma knowledge (n = 279; 71.9%); close to three-fifths had favourable perception of asthma (n = 222; 57.2%). More students in SS2 had good knowledge of asthma compared to those in SS1 (76.7% Vs. 67.2%; ꭓ² = 4.338; P = 0.037). More students in Science class had favourable perceptions about asthma compared to those in Humanities and Business class (60.5% Vs. 48.1% Vs. 25.0%; ꭓ² = 7.458; P = 0.024).

CONCLUSION: Majority of the students were aware about asthma and had good knowledge of the disease while close to three-fifths had favourable perceptions about asthma.

PMID:34224648 | DOI:10.1111/crj.13418

Clin Respir J. 2021 Jul 5. doi: 10.1111/crj.13417. Online ahead of print.

ABSTRACT

BACKGROUND: Co-existence of bronchiectasis with Chronic Obstructive Pulmonary Disease (COPD) may lead to the worsening of the functional parameters in exacerbations and may negatively affect the outcomes.

METHODS: This study is a retrospective cross-sectional study that aims to investigate the relationships between bronchiectasis with COPD exacerbation and all-cause of mortality. We retrospectively enrolled 122 cases hospitalized for COPD exacerbation from 2010 to 2016. Patients who underwent thoracic tomography in the previous year of the index exacerbation were included in the study. Patients who admitted to the intensive care unit, patients with infected bronchiectasis and, with conditions that mimic COPD exacerbation were excluded from the study. Demographic, clinical, and laboratory findings, comorbidities and the number of exacerbations in the previous year, the presence of bronchiectasis were recorded using hospital electronic registry. The radiological evaluation of bronchiectasis was made by the modified Reiff score (MRS).

RESULTS: Bronchiectasis was found in 66 (54%) of 122 patients included in the study. The mean age was 67.5±10.3 in the whole group, 108 (88.5%) of the patients were male and 14 (11.5%) were female. When patients were stratified according to the presence of bronchiectasis, no statistically significant difference was found in terms of comorbidity scores, respiratory functions, exacerbation parameters, laboratory values and all cause of mortality between the groups (p>0.05). There was no statistical relation between the presence of bronchiectasis and long-term survival (log-rank test p=0.83).

CONCLUSIONS: This study shows that patients with bronchiectasis did not cause a poor outcome in patients with COPD exacerbation.

PMID:34224649 | DOI:10.1111/crj.13417

Am J Hematol. 2021 Jul 5. doi: 10.1002/ajh.26286. Online ahead of print.

ABSTRACT

Several controlled studies have evidenced good efficacy and short- and mid-term safety profiles for hydroxyurea (HU), which has become the cornerstone for prevention of sickle-cell disease (SCD)-related vaso-occlusive crises. However, there are few large-scale reports on its long-term use and certain caregivers and patients have concerns about its safety. Following the licensing of HU in Europe for children and adults with severe forms of SCD, ESCORT-HU was designed as a Phase IV observational cohort study. It included 1,906 participants, of whom 55% were adults. The most common hemoglobin (Hb) genotypes were HbSS (84.7%) and HbSβ+ (7.0%). The median duration of follow-up was 45 months, for a total of 7,309 patient-years of observation. The dose of HU after one year was 20.6 mg/kg/d for children and 16.3 mg/kg/d for adults. There was a statistically significant decrease in the number of vaso-occlusive episodes lasting > 48 hours, acute chest syndrome episodes, hospitalizations, and the percentage of patients requiring blood transfusions within the first 12 months relative to the year before enrolment. Neutropenia and thrombocytopenia were the most commonly reported adverse effects. No new HU toxicity was identified. Overall, 125 pregnancies were reported in 101 women and no malformations were observed in the neonates. There were 12 pregnancies for partners of male patients treated with HU. One case of fatal myelodysplastic syndrome was reported, for which a causal association with HU could not be excluded. This cohort study of patients with SCD highlights the positive benefit-to-risk ratio of HU in children and adults. This article is protected by copyright. All rights reserved.

PMID:34224583 | DOI:10.1002/ajh.26286

Neurourol Urodyn. 2021 Jul 5. doi: 10.1002/nau.24740. Online ahead of print.

ABSTRACT

AIM: To compare the efficacy of the treatment with transcutaneous perineal electrostimulation versus intracavitary electrostimulation to reduce the frequency of urinary incontinence after radical prostatectomy and the impact on the quality of life (QoL).

METHODS: This single-blind equivalence-randomized controlled trial equally (1:1) randomly allocated men with urinary incontinence post radical prostatectomy into surface electrodes perineal group (intervention group, IG) and intra-anal probe group (control group, CG). Outcomes included changes in the 24h-Pad Test (main variable), and ICIQ-SF (International Consultation on Incontinence Questionnaire Short-Form), SF-12 (Short Form Health Survey), and I-QOL (incontinence quality of life questionnaire) questionnaires. Clinical data were collected at baseline, 6 and 10 weeks. For the comparisons between variables, χ² test and Student’s t test were used. Equivalence was analyzed by estimating the mean change (90% confidence interval) of urinary incontinence based on the Pad Test. The analysis was performed for the per-protocol and the intention-to-treat populations. Statistical significance level was set at p < 0.05.

RESULTS: Seventy patients were included, mean age 62.8 (SD 9.4) years. Mean baseline 24h-Pad Test was 328.3 g (SD 426.1) and a significant decrease (p < 0.001) in the grams of urine loss at 5 weeks (159.1 g in the IG and 121.7 g in the CG), and at 10 weeks of treatment (248.5 g in the IG and 235.8 g in the CG) was observed. However, the final difference in the grams of urine loss between both treatments showed the absence of statistical significance (p = 0.874). In both groups, the ICIQ-SF, I-QOL, and SF-12 questionnaires revealed a significant improvement in QoL.

CONCLUSION: Surface and intra-anal electrostimulation treatments reduced significantly losses of urine, but differences in grams of urine loss throughout the therapy between groups were not significant, suggesting that the efficacy of the two treatments is not statistically different. Nonetheless, the improvement observed in both groups was statistically significant and clinically relevant.

PMID:34224598 | DOI:10.1002/nau.24740

J Strength Cond Res. 2021 Jun 30. doi: 10.1519/JSC.0000000000004086. Online ahead of print.

ABSTRACT

Szyszka, P and Czaplicki, A. Analysis of record scores in the clean and its variations in the long-term training of young weightlifters. J Strength Cond Res XX(X): 000-000, 2021-The main objectives of this study were to determine the time trajectories of record scores in the clean lift (C) and its derivatives achieved by young weightlifters in a 2-year training cycle and to estimate the quantitative relationships between these scores. The study involved 17 weightlifters who were tested 7 times at 3-month intervals. The computations were based on an individual growth curve approach. The study found statistically significant increases (p < 0.05) in record scores between consecutive measurements until the last measurement for the hang clean (HC), the second to last measurement for the C, and the fourth measurement for the power clean (PC) and the hang power clean (HPC). The overall mean ratios of the record scores in the C to those in the HC, PC, and HPC were approximately constant and amounted to 0.96, 0.89, and 0.80, respectively. Statistically significant differences (p < 0.05) between individual time trajectories of record scores in the C and its derivatives were also identified in the 2 consecutive annual training macrocycles. The results suggest that the long-term analysis of record scores in the C and its derivatives can be useful in assessing athletes’ sport level, in predicting their performance, and in proper exercise selection in the training of young weightlifters.

PMID:34224507 | DOI:10.1519/JSC.0000000000004086

Spine (Phila Pa 1976). 2021 Jul 1. doi: 10.1097/BRS.0000000000004159. Online ahead of print.

ABSTRACT

STUDY DESIGN: Retrospective, randomized, radiographic study assessing age-related changes (ARCs) on lumbar magnetic resonance imaging (MRI) using an ensemble method.

OBJECTIVES: This study proposed to develop a novel reporting method to calculate a predicted “age estimate” for the ARC seen on lumbar MRI.

SUMMARY OF BACKGROUND DATA: Lumbar MRI reports include pathological findings but usually not the prevalence data of common findings which has been shown to decrease the need for narcotics in the management of non-specific lower back pain (NSLBP). Comparing the normal age estimation for lumbar spine degenerative changes/ARC on MRI and comparing this to the patient’s real age may improve patient outcome in the management of NSLBP.

METHODS: A total of 60 lumbar MRI were taken from patients aged between 0 and 100 years. Lumbar MRI features reported as associated with age on review of the literature were measured on each MRI and statistically evaluated for correlation with age. Factors found to be associated were then entered into an ensemble model consisting of several machine learning techniques. The resulting ensemble model was then tested to predict age for a further 10 random lumbar MRI scans. One further lumbar MRI was then assessed for observer variability.

RESULTS: Features that correlated with age were disc signal intensity, the appearance of paravertebral and psoas muscle, disc height, facet joint size, ligamentum flavum thickness, Schmorl nodes, Modic changes, vertebral osteophytes, and high-intensity zones. With the ensemble model, 80% of estimated spinal age were within 11 years of the subjects’ physical age.

CONCLUSION: It would appear that the intervertebral discs, and many other structures that are subjected to loading in and around the lumbar spine change their lumbar MRI appearance in a predictable way with increasing age. ARC on lumbar MRI can be assessed to predict an “expected age” for the subject.Level of Evidence: 2.

PMID:34224512 | DOI:10.1097/BRS.0000000000004159

J Glaucoma. 2021 Jul 1. doi: 10.1097/IJG.0000000000001907. Online ahead of print.

ABSTRACT

PURPOSE: To evaluate the effectiveness of bacterial cellulose membrane (BCM) in preventing fibrosis in trabeculectomy and the biocompatibility of BCM with conjunctiva and sclera.

METHODS: Twenty-one eyes of 21 adult rabbits underwent fornix-based trabeculectomy. Standard surgery was done to control group (CG, n=7). Mitomycin-C (0.3▒mg/mL, 3▒min) was applied to MMC group only (MMCG, n=7). BCM (~100▒µm thick,10×10▒mm,single layer) was covered on the sclerotomy area before conjunctiva was closed in BCM group (BCMG, n=7). Intraocular pressures (IOP) were measured before, and 7, 14, 28 and 45 days after surgery (IOP-POD7,POD14,POD28,POD45). The IOP decrease were expressed as DIOP%-POD7, DIOP%-POD14,DIOP%-POD28 and DIOP%-POD45. The rabbits were sacrificed on the 45th day. Conjunctival vessel (CV) number, degrees of fibrosis, total inflammation, foreign body reaction (FBR), inflammatory cell types (B-cells,T-cells,plasma cells, macrophages, bleb spaces and the expression of α-smooth muscle actin(α-SMA) were studied using histopathology and immunohistochemistry techniques. The groups were compared using nonparametric tests.

RESULTS: There was no statistically significant difference between the groups regarding baseline IOP and DIOP%-POD7 (P>0.05). While DIOP%-POD14, 28 and 45 were similar between BCMG and MMCG, they were significantly lower in CG (P<0.05). The lowest CV number was detected in the MMCG but the difference was not significant. There was no difference between BCMG and CG with regard to the numbers of B-cells, T-cells and macrophages, however these cells were significantly lower in MMCG (P<0.05). Five cases had mild and 2 cases had moderate FBR in the BCMG. There was mild to moderate inflammation in all BCM cases. While fibrosis and α-SMA staining were higher in the CG (P<0.001), they were minimal in the BCM and MMC groups.

CONCLUSIONS: BCM showed good biocompatibility and provided better control of IOP with minimal fibrosis in trabeculectomy site compared to the control group.

PMID:34224487 | DOI:10.1097/IJG.0000000000001907

J Pediatr Gastroenterol Nutr. 2021 Jun 28. doi: 10.1097/MPG.0000000000003220. Online ahead of print.

ABSTRACT

OBJECTIVE: Cannabis Hyperemesis Syndrome (CHS) is characterized by recurrent episodes of intractable emesis associated with heavy use of cannabis. Recognition of CHS can be problematic due to the lack of specific biomarkers, which can point the clinician to the diagnosis. We present, retrospectively, a series of adolescent/young adult patients who presented to a pediatric gastroenterology (GI) service with acute on chronic nausea and vomiting, subsequently found to have CHS with associated elevated urinary cannabis metabolite concentrations.

METHODS: We describe 15 patients referred to our pediatric GI division for intractable emesis with spot urinary cannabis metabolite carboxy-THC (THC-COOH) concentrations from January 1, 2018 through April 20, 2019. Urinary testing was performed using gas chromatography mass spectrometry (GC-MS) in a manner consistent with CLIA requirements at Mayo Clinic laboratory (Rochester, MN). The laboratory cutoffs were 3.0 ng/mL. Data was extracted via chart review and analyzed via online statistical application.

RESULTS: Fifteen patients (7 females, 8 males) were studied with an average age of 17.7 years. All patients reported frequent cannabis use for at least 1 month and exhibited intractable, non-bilious emesis for at least 2 weeks. Twelve patients also reported weight loss. Two patients had underlying gastrointestinal disease (one with Crohn’s Disease and one with irritable bowel syndrome). All patients had essentially normal GI workup including laboratory tests, imaging studies and endoscopies.Fourteen of 15 patients had urinary THC-COOH concentrations > 100ng/mL, with 7 individuals exhibiting levels > 500ng/mL. One patient had a urinary TCH-COOH concentration level under 100ng/mL had not used cannabis for 2 weeks. Most other patients had used cannabis within 2 days of providing a urine sample. The Binomial test for CHS patients with urinary THC-COOH levels over 100ng/mL was significant with a p-value of < 0.0005 (one tail test).

CONCLUSION: Cannabis Hyperemesis Syndrome is associated with an elevated urinary THC-COOH level usually exceeding 100ng/mL, which is indicative of significant chronic cannabis exposure. In patients with a history consistent with CHS, urine THC-COOH testing may help guide the diagnostic evaluation of these patients and decrease the need for further workup.

PMID:34224490 | DOI:10.1097/MPG.0000000000003220

Pain. 2021 Jun 29. doi: 10.1097/j.pain.0000000000002385. Online ahead of print.

ABSTRACT

Quantitative Sensory Testing (QST) can be useful to identify high-risk patients for the development of chronic postsurgical pain (CPSP). This systematic review aims to assess if presurgical sensory sensitivity measured using QST is associated with acute and CPSP after total joint arthroplasty.A systematic search was performed in Sep/2020 in PubMed, EMBASE, Web of Science and Scopus, using terms related to total joint arthroplasty and QST. Prospective studies were included if they reported an association between presurgical QST and postsurgical pain in adults with osteoarthritis undergoing primary unilateral total joint arthroplasty.From 2994 identified studies, 18 met the inclusion criteria (1869 patients). Total knee arthroplasty was the most common surgery (16 studies) and pressure pain threshold (PPT) was the most common test (11 studies), followed by dynamic measures (9 studies). Postsurgical pain was assessed at acute (5 studies), subacute (2 studies) and chronic (13 studies) time points. Risk of bias was assessed using the Quality in Prognosis Studies Tool, and evaluated as low-to-moderate in most domains. Fourteen studies reported at least one statistically significant association between QST and pain (acute: 4 studies, subacute: 1 study, chronic: 9 studies). PPT was associated with postsurgical pain in 6 studies (out of 11, 55%), heat pain threshold in 2 (out of 6, 33%), conditioned pain modulation in 1 (out of 6, 17%) and temporal summation of pain in 5 (out of 8, 63%). The predictive role of presurgical QST for post-arthroplasty pain remains unclear, mainly due to heterogeneous methodologies and inconsistent results.

PMID:34224493 | DOI:10.1097/j.pain.0000000000002385