Tag: statistics

Int J Epidemiol. 2023 May 17:dyad062. doi: 10.1093/ije/dyad062. Online ahead of print.

ABSTRACT

It is well-known that designing a cluster randomized trial (CRT) requires an advance estimate of the intra-cluster correlation coefficient (ICC). In the case of longitudinal CRTs, where outcomes are assessed repeatedly in each cluster over time, estimates for more complex correlation structures are required. Three common types of correlation structures for longitudinal CRTs are exchangeable, nested/block exchangeable and exponential decay correlations-the latter two allow the strength of the correlation to weaken over time. Determining sample sizes under these latter two structures requires advance specification of the within-period ICC and cluster autocorrelation coefficient as well as the intra-individual autocorrelation coefficient in the case of a cohort design. How to estimate these coefficients is a common challenge for investigators. When appropriate estimates from previously published longitudinal CRTs are not available, one possibility is to re-analyse data from an available trial dataset or to access observational data to estimate these parameters in advance of a trial. In this tutorial, we demonstrate how to estimate correlation parameters under these correlation structures for continuous and binary outcomes. We first introduce the correlation structures and their underlying model assumptions under a mixed-effects regression framework. With practical advice for implementation, we then demonstrate how the correlation parameters can be estimated using examples and we provide programming code in R, SAS, and Stata. An Rshiny app is available that allows investigators to upload an existing dataset and obtain the estimated correlation parameters. We conclude by identifying some gaps in the literature.

PMID:37196320 | DOI:10.1093/ije/dyad062

Dermatol Pract Concept. 2023 Apr 1;13(2). doi: 10.5826/dpc.1302a134. Online ahead of print.

ABSTRACT

INTRODUCTION: Psoriasis is an immune-mediated, chronic and inflammatory disease whose pathogenesis is affected by the interactions of several immune cells and cytokines. PD-1 is an inhibitor receptor that is expressed to a large extent in T lymphocytes and responsible for regulating autoimmunity and self-tolerance.

OBJECTIVES: In this study, we aimed to investigate the expression of PD-1/PD-L molecules in the lesioned skins of psoriasis patients.

METHODS: The study included 30 psoriasis patients, and 15 healthy volunteers as the control group. Anti PD-1 and PD-L1 antibodies were applied to the skin biopsy samples that were collected from the patient and control groups. Cytoplasmic and membranous staining of PD-1 and PD-L1 were considered positive. The number of stained immune cells that was examined for each case.

RESULTS: The percentage of the tissues with high PD-1 (+) and PDL-1 (+) immune cell counts were significantly higher in the psoriasis patients compared to healthy controls (P values = 0.004 and 0.002, respectively). A negative and statistically significant correlation was detected between PDL-1(+) immune cell numbers and PASI scores (P = 0.033, r=-0.57).

CONCLUSIONS: In the lesioned skin samples of psoriasis patients, the PD-1 and PD-L1 expressions were significantly higher in immune cells than that in the skin samples of the healthy controls. This study was the first investigation of the expression of PD-1/PD-L molecules in the immune cells in found the lesioned skins of psoriasis patients.

PMID:37196303 | DOI:10.5826/dpc.1302a134

Dermatol Pract Concept. 2023 Apr 1;13(2). doi: 10.5826/dpc.1302a116. Online ahead of print.

ABSTRACT

INTRODUCTION: Psoriasis is an inflammatory disease that can cause cardiovascular comorbidities. Some recent studies have indicated that impaired gut microbiota and metabolites may be associated with inflammatory diseases.

OBJECTIVES: In this study, the relationship between serum trimethylamine n-oxide (TMAO, a gut bacterial metabolite) level and carotid intima-media thickness (CIMT) and disease severity in psoriasis patients was investigated.

METHODS: Age- and gender-matched 73 patients and 72 healthy controls were included in the study. In both groups serum trimethylamine n-oxide(TMAO), oxidized low-density lipoprotein (ox-LDL), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglyceride, total cholesterol, high-sensitivity C-reactive protein (hs-CRP), creatinine, aspartate aminotransferase (AST) and alanine aminotransferase(ALT) levels were recorded and the carotid intima-media thickness (CIMT) was measured by B-mode ultrasonography by a cardiologist.

RESULTS: TMAO, hs-CRP, oxidized-LDL, triglyceride and CIMT levels were statistically higher in the patient group. HDL levels were statistically higher in the control group. There was no significant difference between the two groups in terms of total cholesterol and LDL-C levels. In partial correlation analyzes in the patient group, positive correlations were observed between TMAO and CIMT, LDL-C and total cholesterol levels. Linear regression analysis showed that TMAO levels positively predicted CIMT levels.

CONCLUSIONS: This study confirmed that psoriasis is a risk factor for the development of cardiovascular disease and that elevated serum TMAO levels in these patients indicate the presence of intestinal dysbiosis. Furthermore, TMAO levels were found to be a predictor of the risk of developing cardiovascular disease in psoriasis patients.

PMID:37196276 | DOI:10.5826/dpc.1302a116

Dermatol Pract Concept. 2023 Apr 1;13(2). doi: 10.5826/dpc.1302a120. Online ahead of print.

ABSTRACT

INTRODUCTION: Effective communication is an important issue in patient-doctor interaction which is even more important regarding chronic disorders which need a strong relationship between patient and clinician for better compliance and optimal control disease.

OBJECTIVES: This study was aimed to develop the best cultural adapted Persian version of the 28-item Calgary- Cambridge Observation Guide (CCOG) questionnaire.

METHODS: In this descriptive-analytic study, data collected from 400 patients attending the outpatient dermatology clinics of 3 major hospitals in Tehran using the modified Persian version of CCOG questionnaire, both before and after being visited by dermatologists.

RESULTS: The difference of CCG scores for all of questions, except for questions number 1,16 and 22, was statistically significant. The highest score, both before and after visiting, attained by question regarding being respectful. The lowest scores for necessary behavior and the adequate amount of execution were related to questions number 3 (Introducing self) and 4 (Introducing role), respectively. Age and educational level of patients were significantly correlated with their expectations regarding communication skills of clinician.

CONCLUSIONS: This study showed the acceptable validity of modified Persian version of CCOG-24 item questionnaire. Our findings also demonstrated that there was a significant difference between what patients expected from a dermatologist and the manner they actually were treated regarding physician communication skills.

PMID:37196253 | DOI:10.5826/dpc.1302a120

J Am Chem Soc. 2023 May 17. doi: 10.1021/jacs.3c02041. Online ahead of print.

ABSTRACT

Cation-disordered rock-salt (DRX) materials receive intensive attention as a new class of cathode candidates for high-capacity lithium-ion batteries (LIBs). Unlike traditional layered cathode materials, DRX materials have a three-dimensional (3D) percolation network for Li⁺ transportation. The disordered structure poses a grand challenge to a thorough understanding of the percolation network due to its multiscale complexity. In this work, we introduce the large supercell modeling for DRX material Li_1.16Ti_0.37Ni_0.37Nb_0.10O₂ (LTNNO) via the reverse Monte Carlo (RMC) method combined with neutron total scattering. Through a quantitative statistical analysis of the material’s local atomic environment, we experimentally verified the existence of short-range ordering (SRO) and uncovered an element-dependent behavior of transition metal (TM) site distortion. A displacement from the original octahedral site for Ti⁴⁺ cations is pervasive throughout the DRX lattice. Density functional theory (DFT) calculations revealed that site distortions quantified by the centroid offsets could alter the migration barrier for Li⁺ diffusion through the tetrahedral channels, which can expand the previously proposed theoretical percolating network of Li. The estimated accessible Li content is highly consistent with the observed charging capacity. The newly developed characterization method here uncovers the expandable nature of the Li percolation network in DRX materials, which may provide valuable guidelines for the design of superior DRX materials.

PMID:37196223 | DOI:10.1021/jacs.3c02041

J Child Adolesc Psychopharmacol. 2023 May 17. doi: 10.1089/cap.2023.0006. Online ahead of print.

ABSTRACT

Objectives: (1) To examine psychiatric and developmental comorbidities in school-age children and adolescents with Autism in a university-affiliated urban developmental center that serves children with developmental disabilities, and (2) to compare comorbidities by age groups. Methods: Review of all school-age children and adolescents evaluated and diagnosed with autism from 1/2019 to 1/2022. Data included: Demographics (age, gender, race/ethnic group, bilingual English/Spanish households) and other developmental and psychiatric diagnoses besides autism, including language disorder, specific learning disorders (LD), attention-deficit/hyperactivity disorder (ADHD), intellectual disabilities (ID), anxiety disorders (i.e., generalized anxiety disorder, anxiety disorder, unspecified, social anxiety disorder), and depressive disorders (i.e., major depressive disorder, depressive disorder, unspecified). Statistics included chi-square, and nonparametric tests, comorbidities were compared between school-age children and adolescents. Results: Of all children evaluated in that period (n = 599), 119 (20%) were diagnosed with autism, 97 (81%) boys, age 11.8 ± 3 years old, 46 (39%) bilingual English/Spanish households; 65 (55%) were school-age children and 54 (45%) were adolescents (age = 12-18). Of the 119, 115 (96%) presented with one or more co-occurring conditions, including language disorder in 101 (85%), LD in 23 (19%), ADHD in 50 (42%), and ID in 30 (25%). Psychiatric co-occurring conditions included anxiety disorders in 24 (20%) and depressive disorders in 8 (6%). School-age children with autism were more likely to be diagnosed with ADHD combined type (42% vs. 22%, p = 0.04) and language disorders (91% vs. 73%, p = 0.04), whereas adolescents with autism were more likely to be diagnosed with depressive disorders (13% vs. 1%, p = 0.03), with no other differences between the groups. Conclusion: In this urban, ethnically diverse group of children with autism, the vast majority presented with one or more comorbid diagnoses. School-age children were more likely to be diagnosed with language disorder and ADHD, while adolescents were more likely to be diagnosed with depression. Early detection and treatment of co-occurring conditions in autism are necessary.

PMID:37196211 | DOI:10.1089/cap.2023.0006

Health Aff (Millwood). 2023 May 17:101377hlthaff202201502. doi: 10.1377/hlthaff.2022.01502. Online ahead of print.

ABSTRACT

Social determinants of health can adversely affect health and therefore lead to poor health care outcomes. When it launched in 2017, the Accountable Health Communities (AHC) Model was at the forefront of US health policy initiatives seeking to address social determinants of health. The AHC Model, sponsored by the Centers for Medicare and Medicaid Services, screened Medicare and Medicaid beneficiaries for health-related social needs and offered eligible beneficiaries assistance in connecting with community services. This study used data from the period 2015-21 to test whether the model had impacts on health care spending and use. Findings show statistically significant reductions in emergency department visits for both Medicaid and fee-for-service Medicare beneficiaries. Impacts on other outcomes were not statistically significant, but low statistical power may have limited our ability to detect model effects. Interviews with AHC Model participants who were offered navigation services to help them find community-based resources suggested that navigation services could have directly affected the way in which beneficiaries engage with the health care system, leading them to be more proactive in seeking appropriate care. Collectively, findings provide mixed evidence that engaging with beneficiaries who have health-related social needs can affect health care outcomes.

PMID:37196210 | DOI:10.1377/hlthaff.2022.01502

J Phys Chem B. 2023 May 17. doi: 10.1021/acs.jpcb.3c00117. Online ahead of print.

ABSTRACT

Atomistic simulations with reliable models are extremely useful in providing exquisitely detailed pictures of biomolecular phenomena that are not always accessible to experiments. One such biomolecular phenomenon is RNA folding, which often requires exhaustive simulations with combined advanced sampling techniques. In this work, we employed the multithermal-multiumbrella on-the-fly probability enhanced sampling (MM-OPES) technique and compared it against combined parallel tempering and metadynamics simulations. We found that MM-OPES simulations were successful in reproducing the free energy surfaces from combined parallel tempering and metadynamics simulations. Importantly, we also investigated a wide range of temperature sets (minimum and maximum temperatures) for MM-OPES simulations in order to identify some guidelines for deciding the temperature limits for an accurate and efficient exploration of the free energy landscapes. We found that most temperature sets yielded almost the same accuracy in reproducing the free energy surface at the ambient conditions as long as (i) the maximum temperature is reasonably high, (ii) the temperature at which we run the simulation is reasonably high (in our simulations, running temperature is defined as [minimum temperature + maximum temperature]/2), and (iii) the effective sample size at the temperature of interest is statistically reasonable. In terms of the computational cost, all MM-OPES simulations were nearly 4 times less costly than the combined parallel tempering and metadynamics simulations. We concluded that the demanding combined parallel tempering and metadynamics simulations can safely be replaced with approximately 4 times less costly MM-OPES simulations (with carefully selected temperature limits) to obtain the same information.

PMID:37196167 | DOI:10.1021/acs.jpcb.3c00117

Br J Surg. 2023 May 17:znad123. doi: 10.1093/bjs/znad123. Online ahead of print.

ABSTRACT

BACKGROUND: Anastomotic leak is a severe complication after oesophagectomy. Anastomotic leak has diverse clinical manifestations and the optimal treatment strategy is unknown. The aim of this study was to assess the efficacy of treatment strategies for different manifestations of anastomotic leak after oesophagectomy.

METHODS: A retrospective cohort study was performed in 71 centres worldwide and included patients with anastomotic leak after oesophagectomy (2011-2019). Different primary treatment strategies were compared for three different anastomotic leak manifestations: interventional versus supportive-only treatment for local manifestations (that is no intrathoracic collections; well perfused conduit); drainage and defect closure versus drainage only for intrathoracic manifestations; and oesophageal diversion versus continuity-preserving treatment for conduit ischaemia/necrosis. The primary outcome was 90-day mortality. Propensity score matching was performed to adjust for confounders.

RESULTS: Of 1508 patients with anastomotic leak, 28.2 per cent (425 patients) had local manifestations, 36.3 per cent (548 patients) had intrathoracic manifestations, 9.6 per cent (145 patients) had conduit ischaemia/necrosis, 17.5 per cent (264 patients) were allocated after multiple imputation, and 8.4 per cent (126 patients) were excluded. After propensity score matching, no statistically significant differences in 90-day mortality were found regarding interventional versus supportive-only treatment for local manifestations (risk difference 3.2 per cent, 95 per cent c.i. -1.8 to 8.2 per cent), drainage and defect closure versus drainage only for intrathoracic manifestations (risk difference 5.8 per cent, 95 per cent c.i. -1.2 to 12.8 per cent), and oesophageal diversion versus continuity-preserving treatment for conduit ischaemia/necrosis (risk difference 0.1 per cent, 95 per cent c.i. -21.4 to 1.6 per cent). In general, less morbidity was found after less extensive primary treatment strategies.

CONCLUSION: Less extensive primary treatment of anastomotic leak was associated with less morbidity. A less extensive primary treatment approach may potentially be considered for anastomotic leak. Future studies are needed to confirm current findings and guide optimal treatment of anastomotic leak after oesophagectomy.

PMID:37196149 | DOI:10.1093/bjs/znad123

Sci Adv. 2023 May 19;9(20):eade7172. doi: 10.1126/sciadv.ade7172. Epub 2023 May 17.

ABSTRACT

Adverse conditions in early life can have negative consequences for adult health and survival in humans and other animals. What variables mediate the relationship between early adversity and adult survival? Adult social environments represent one candidate: Early life adversity is linked to social adversity in adulthood, and social adversity in adulthood predicts survival outcomes. However, no study has prospectively linked early life adversity, adult social behavior, and adult survival to measure the extent to which adult social behavior mediates this relationship. We do so in a wild baboon population in Amboseli, Kenya. We find weak mediation and largely independent effects of early adversity and adult sociality on survival. Furthermore, strong social bonds and high social status in adulthood can buffer some negative effects of early adversity. These results support the idea that affiliative social behavior is subject to natural selection through its positive relationship with survival, and they highlight possible targets for intervention to improve human health and well-being.

PMID:37196090 | DOI:10.1126/sciadv.ade7172