Category: Statistics

BMC Prim Care. 2022 Aug 16;23(1):208. doi: 10.1186/s12875-022-01811-x.

ABSTRACT

BACKGROUND: Obesity is a chronic disease with increasing prevalence. We aimed to explore primary care physicians’ knowledge and attitudes about obesity and how knowledge and attitudes are associated with confidence and adherence to obesity guidelines and barriers to obesity treatment.

METHODS: A questionnaire survey was sent by e-mail to 1642 primary care physicians in four regions in Sweden. The survey focused on the physicians’ knowledge, attitudes towards obesity, confidence in obesity management, adherence to obesity guidelines and barriers to optimal care. We created different statistical indices for knowledge, attitudes and adherence. To analyse the correlation between these indices, we used linear regression analyses.

RESULTS: Replies from 235 primary care physicians yielded a response rate of 14.3%. Most physicians answered correctly that obesity is a disease (91%), that obesity regulation sits in the hypothalamus (70%) and that obesity is due to disorders of appetite regulation (69%). However, 44% of the physicians thought that the most effective weight reduction method for severe obesity was lifestyle changes; 47% believed that obesity is due to lack of self-control, 14% mentioned lack of motivation and 22% stated laziness. Although 97% believed that physicians can help individuals with obesity and 56% suggested that obesity treatment should be prioritised, 87% of the physicians expressed that losing weight is the patients’ responsibility. There was a positive association between higher knowledge and better adherence to obesity guidelines (B = 0.07, CI 0.02-0.12, p-value = 0.005) and feeling confident to suggest medication (p < 0.001) or bariatric surgery (p = 0.002). While 99% of the physicians felt confident to discuss lifestyle changes, 67% and 81% were confident to suggest medication or bariatric surgery, respectively. Respondents perceived that the greatest barrier in obesity management was lack of time (69%) and resources (49%).

CONCLUSION: There was a positive association between Swedish primary care physicians’ knowledge and adherence to obesity guidelines and being more confident to suggest obesity treatment. Yet, many physicians had an ambivalent attitude towards obesity management.

PMID:35971075 | DOI:10.1186/s12875-022-01811-x

BMC Med Res Methodol. 2022 Aug 15;22(1):228. doi: 10.1186/s12874-022-01683-w.

ABSTRACT

BACKGROUND: Platform trials can evaluate the efficacy of several experimental treatments compared to a control. The number of experimental treatments is not fixed, as arms may be added or removed as the trial progresses. Platform trials are more efficient than independent parallel group trials because of using shared control groups. However, for a treatment entering the trial at a later time point, the control group is divided into concurrent controls, consisting of patients randomised to control when that treatment arm is in the platform, and non-concurrent controls, patients randomised before. Using non-concurrent controls in addition to concurrent controls can improve the trial’s efficiency by increasing power and reducing the required sample size, but can introduce bias due to time trends.

METHODS: We focus on a platform trial with two treatment arms and a common control arm. Assuming that the second treatment arm is added at a later time, we assess the robustness of recently proposed model-based approaches to adjust for time trends when utilizing non-concurrent controls. In particular, we consider approaches where time trends are modeled either as linear in time or as a step function, with steps at time points where treatments enter or leave the platform trial. For trials with continuous or binary outcomes, we investigate the type 1 error rate and power of testing the efficacy of the newly added arm, as well as the bias and root mean squared error of treatment effect estimates under a range of scenarios. In addition to scenarios where time trends are equal across arms, we investigate settings with different time trends or time trends that are not additive in the scale of the model.

RESULTS: A step function model, fitted on data from all treatment arms, gives increased power while controlling the type 1 error, as long as the time trends are equal for the different arms and additive on the model scale. This holds even if the shape of the time trend deviates from a step function when patients are allocated to arms by block randomisation. However, if time trends differ between arms or are not additive to treatment effects in the scale of the model, the type 1 error rate may be inflated.

CONCLUSIONS: The efficiency gained by using step function models to incorporate non-concurrent controls can outweigh potential risks of biases, especially in settings with small sample sizes. Such biases may arise if the model assumptions of equality and additivity of time trends are not satisfied. However, the specifics of the trial, scientific plausibility of different time trends, and robustness of results should be carefully considered.

PMID:35971069 | DOI:10.1186/s12874-022-01683-w

BMC Ecol Evol. 2022 Aug 15;22(1):100. doi: 10.1186/s12862-022-02054-1.

ABSTRACT

BACKGROUND: Contemporary species distribution, genetic diversity and evolutionary history in many taxa are shaped by both historical and current climate as well as topography. The Himalayas show a huge variation in topography and climatic conditions across its entire range, and have experienced major climatic fluctuations in the past. However, very little is known regarding how this heterogenous landscape has moulded the distribution of Himalayan fauna. A recent study examined the effect of these historical events on the genetic diversity of the Himalayan langurs in Nepal Himalaya. However, this study did not include the samples from the Indian Himalayan region (IHR). Therefore, here we revisit the questions addressed in the previous study with a near complete sampling from the IHR, along with the samples from the Nepal Himalaya. We used the mitochondrial Cytochrome-b (Cyt-b, 746 bp) region combined with multiple phylogeographic analyses and palaeodistribution modelling.

RESULTS: Our dataset contained 144 sequences from the IHR as well as the Nepal Himalaya. Phylogenetic analysis showed a low divergent western clade nested within high divergent group of eastern lineages and in the network analysis we identified 22 haplotypes over the entire distribution range of the Himalayan langurs. Samples from the Nepal Himalaya showed geographically structured haplotypes corresponding to different river barriers, whereas samples from IHR showed star-like topology with no structure. Our statistical phylogeography analysis using diyABC supported the model of east to west colonisation of these langurs with founder event during colonisation. Analysis of demographic history showed that the effective population size of the Himalayan langurs decreased at the onset of last glacial maximum (LGM) and started increasing post LGM. The palaeodistribution modelling showed that the extent of suitable habitat shifted from low elevation central Nepal, and adjoining parts of north India, during LGM to the western Himalaya at present.

CONCLUSION: The current genetic diversity and distribution of Himalayan langurs in the Nepal Himalaya has been shaped by river barriers, whereas the rivers in the IHR had relatively less time to act as a strong genetic barrier after the recent colonisation event. Further, the post LGM expansion could have had confounding effect on Himalayan langur population structure in both Nepal Himalaya and IHR.

PMID:35971061 | DOI:10.1186/s12862-022-02054-1

Fish Physiol Biochem. 2022 Aug 16. doi: 10.1007/s10695-022-01113-0. Online ahead of print.

ABSTRACT

Vanadium (V) is a toxicant becoming increasingly concentrated in freshwater with the potential to affect aquatic organisms. Vanadium pentoxide (V₂O₅), accumulated in fish, can act as an oxidizing agent and cause oxidative damage. To determine the effects of V₂O₅ on exposed adult Oreochromis mossambicus, acute exposure experiments were conducted. Bioaccumulation and biomarker analyses were performed on various excised tissues of the exposed fish. As expected, accumulated V concentrations in the gills increased as the exposure concentration increased. Gill tissue accumulated more vanadium than muscle tissue. Metallothionein content increased in the highest concentrations compared to the lower concentrations, therefore showing that metallothionein proteins were attempting to sequester V₂O₅ in the tissues. Superoxide dismutase (SOD) showed an excitation at lower concentrations and inhibition as the exposure concentrations increased, possibly due to ROS detoxification. Catalase activity decreased from the first exposure concentration to the last concentration; this could have been due to SOD compensation. Protein carbonyl concentration decreased as the concentrations of V₂O₅ increased, indicating an inhibition of protein oxidation. The IBRv2 comparison revealed the biochemical responses caused by V₂O₅ more effectively than traditional statistical analysis.

PMID:35971046 | DOI:10.1007/s10695-022-01113-0

Biol Futur. 2022 Aug 15. doi: 10.1007/s42977-022-00131-6. Online ahead of print.

ABSTRACT

Cantharellus cibarius is a wild edible mushrooms and considered as a plethora of compounds with potential biotechnological applications. This study highlighted the utilization of C. cibarius mushroom in the production of extracellular lipase under submerged fermentation, representing the first report on lipase production by this mushroom. Various physicochemical factors were optimized via one-factor-at-a time (OFAT) method. Maximum enzyme production was recorded when the mushroom mycelium was grown at 30 °C on pH 6.0 for 96 h in the medium supplemented with 1% [(v/v)] olive oil. Productivity of enzyme was affected by variation in the nitrogen sources, carbon sources, metal ions and NaCl salt. Glucose and peptone significantly enhanced enzyme production as carbon and nitrogen sources, respectively. Stimulatory and inhibitory effects were found by Ca²⁺ and Zn²⁺ ions, respectively. Furthermore, Box-Behnken Design (BBD) of Response Surface Methodology (RSM) was employed to optimize the interactive effects of specific media components like glucose, olive oil and CaCl₂. The regression model was significant with a coefficient of determination (R²) value of 0.9483. Statistically optimized design (RSM) resulted approximately two-fold increase (23.5-42.283 UmL^-1) of lipase production than classical optimization method (OFAT), confirmed the validation of model. The kinetic parameters for p-nitrophenyl palmitate hydrolysis, K_m and V_max were 5.24 mM and 0.768 mmol/min/mg respectively, established a high affinity for the substrate.

PMID:35971039 | DOI:10.1007/s42977-022-00131-6

Biom J. 2022 Aug 15. doi: 10.1002/bimj.202100343. Online ahead of print.

ABSTRACT

One-inflation in zero-truncated count data has recently found considerable attention. There are currently two views in the literature. In the first approach, the untruncated model is considered as one-inflated whereas in the second approach the truncated model is viewed as one-inflated. Here, we show that both models have identical model spaces as well as identical maximum likelihoods. Consequences of population size estimation are illuminated, and the findings are illustrated at hand of two case studies.

PMID:35971027 | DOI:10.1002/bimj.202100343

Lasers Med Sci. 2022 Aug 15. doi: 10.1007/s10103-022-03622-z. Online ahead of print.

ABSTRACT

Facial pores are visible openings of pilosebaceous follicles, and they are one of the major factors influencing facial skin appearance. This article aims to evaluate and compare the efficacy and safety of 1565-nm non-ablative fractional laser (NAFL) and long-pulsed 1064-nm Nd:YAG laser (LPNY) in treating enlarged facial pores. All subjects were treated with NAFL on their left faces and LPNY on their right. Five treatments were administered at 2-week intervals, with one follow-up session 2 months after the final treatment. Treatment efficacy was evaluated by subjective (pore improvement and subject satisfaction ratings) assessments and objective (pore number) assessments. At each appointment, any side effects or complications were recorded to evaluate the safety of the two lasers. A total of 18 individuals participated in this study. At the 2-month follow-up, NAFL and LPNY sides had significant reduction in pores (p < 0.0001 and p < 0.0001, respectively). However, there was no statistically significant difference in the mean number of pore reductions on either side (p > 0.05). There was no significant difference in pore improvement ratings and satisfaction ratings between the two sides (p > 0.05 and p > 0.05, respectively). Both lasers showed minimal side effects. Both lasers effectively treated enlarged facial pores and were well tolerated. The side effects of the 1064-nm LPNY were less severe than those of the 1565-nm NAFL. ClinicalTrial.gov Identifier: NCT05360043.

PMID:35971017 | DOI:10.1007/s10103-022-03622-z

Sci Rep. 2022 Aug 15;12(1):13816. doi: 10.1038/s41598-022-16170-x.

ABSTRACT

Battlefield injury management requires specialized care, and wound infection is a frequent complication. Challenges related to characterizing relevant pathogens further complicates treatment. Applying metagenomics to wounds offers a comprehensive path toward assessing microbial genomic fingerprints and could indicate prognostic variables for future decision support tools. Wound specimens from combat-injured U.S. service members, obtained during surgical debridements before delayed wound closure, were subjected to whole metagenome analysis and targeted enrichment of antimicrobial resistance genes. Results did not indicate a singular, common microbial metagenomic profile for wound failure, instead reflecting a complex microenvironment with varying bioburden diversity across outcomes. Genus-level Pseudomonas detection was associated with wound failure at all surgeries. A logistic regression model was fit to the presence and absence of antimicrobial resistance classes to assess associations with nosocomial pathogens. A. baumannii detection was associated with detection of genomic signatures for resistance to trimethoprim, aminoglycosides, bacitracin, and polymyxin. Machine learning classifiers were applied to identify wound and microbial variables associated with outcome. Feature importance rankings averaged across models indicated the variables with the largest effects on predicting wound outcome, including an increase in P. putida sequence reads. These results describe the microbial genomic determinants in combat wound bioburden and demonstrate metagenomic investigation as a comprehensive tool for providing information toward aiding treatment of combat-related injuries.

PMID:35970993 | DOI:10.1038/s41598-022-16170-x

Menopause. 2022 Aug 16. doi: 10.1097/GME.0000000000002025. Online ahead of print.

ABSTRACT

OBJECTIVE: The aim of this study was to measure the impact of different risk factors in middle-aged women on longevity evaluated after three decades of an initial health screening.

METHODS: Women who received an annual check-up between 1990 and 1993 were recruited. Anamnesis and physical examination were recorded. Blood samples for the measurement of glycemia and lipids were taken. Data are reported as of December 2021.

RESULTS: A total of 1,158 women aged 40 to 60 were studied. At 30.9 years of follow-up, the Kaplan-Meier overall survival was 75.6% (95% confidence interval, 72.6-78.3). The main causes of the 260 deaths observed were the following: cancer (n = 88; 33.8%), cardiovascular disease (n = 55; 21.2%), and infectious disease (n = 41; 15.8%). The following hazard ratios were found with the flexible parametric survival model: personal history of fracture (hazard ratio, 2.55; 95% confidence interval, 1.29-5.02; P = 0.007), type 2 diabetes mellitus (2.14; 1.18-3.88; P = 0.012), personal history of heart disease (1.85; 1.09-3.13; P = 0.022), chronic arterial hypertension (1.65; 1.25-2.17; P < 0.001), postmenopausal status (1.60; 1.13-2.26; P = 0.008), unskilled jobs (1.56; 1.17-2.07; P = 0.002), cigarette smoking (1.51; 1.17-1.94; P = 0.002), age (1.06; 1.03-1.09; P < 0.001), body mass index (1.04; 1.01-1.07; P = 0.004), multiparous (0.72; 0.56-0.93; P = 0.012), and active sexual intercourse (0.68; 0.52-0.87; P = 0.003). Lipid disorders did not reach statistical significance as a risk factor.

CONCLUSIONS: In this cohort, it was observed that most of the classic risk factors for mortality were present. However, a history of fracture appears in middle-aged women as a strong predictor of mortality, surpassing diabetes and arterial hypertension. Multiparity, on the other hand, was a protective factor.

PMID:35969889 | DOI:10.1097/GME.0000000000002025

Blood. 2022 Aug 19:blood.2022015790. doi: 10.1182/blood.2022015790. Online ahead of print.

ABSTRACT

The frequency of pathogenic/likely pathogenic (P/LP) germline variants in myelodysplastic syndrome (MDS) patients diagnosed at or younger than 40 years old is 15 to 20%. However, there are no comprehensive studies assessing the frequency of such variants across the age spectrum. We performed augmented whole exome sequencing from peripheral blood of 404 MDS patients and their related donors prior to allogeneic hematopoietic stem cell transplantation. Single nucleotide and copy number variants in 233 genes were analyzed and interpreted. Germline status was established by the presence of a variant in the patient and related donor or for those seen previously only as germline alleles. We identified P/LP germline variants in 28 out of 404 MDS patients (7%) within all age deciles. Patients with P/LP variants were more likely to develop higher-grade MDS than those without (43% vs. 25%, p=0.04). There was no statistical difference in outcome parameters between patients with and without a germline variant, but the analysis was underpowered. P/LP variants in bone marrow failure syndrome genes were found in five patients under age 40, whereas variants in DDX41 (n=4), telomere biology disorder genes (n=2), and tumor predisposition genes (n=17) were found in patients over 40. If presumed germline variants were included, the yield of P/LP variants would increase to 11% and by adding suspicious variants of unknown significance, it would rise further to 12%. The high frequency of P/LP germline variants in our study supports comprehensive germline genetic testing for all MDS patients regardless of their age at diagnosis.

PMID:35969835 | DOI:10.1182/blood.2022015790