Category: Nevin Manimala

Stat Med. 2022 Mar 17. doi: 10.1002/sim.9376. Online ahead of print.

ABSTRACT

The article develops marginal models for multivariate longitudinal responses. Overall, the model consists of five regression submodels, one for the mean and four for the covariance matrix, with the latter resulting by considering various matrix decompositions. The decompositions that we employ are intuitive, easy to understand, and they do not rely on any assumptions such as the presence of an ordering among the multivariate responses. The regression submodels are semi-parametric, with unknown functions represented by basis function expansions. We use spike-slap priors for the regression coefficients to achieve variable selection and function regularization, and to obtain parameter estimates that account for model uncertainty. An efficient Markov chain Monte Carlo algorithm for posterior sampling is developed. The simulation study presented investigates the gains that one may have when considering multivariate longitudinal analyses instead of univariate ones, and whether these gains can counteract the negative effects of missing data. We apply the methods on a highly unbalanced longitudinal dataset with four responses observed over a period of 20 years.

PMID:35699116 | DOI:10.1002/sim.9376

Stat Med. 2022 Mar 14. doi: 10.1002/sim.9373. Online ahead of print.

ABSTRACT

The mixture cure model for analyzing survival data is characterized by the assumption that the population under study is divided into a group of subjects who will experience the event of interest over some finite time horizon and another group of cured subjects who will never experience the event irrespective of the duration of follow-up. When using the Bayesian paradigm for inference in survival models with a cure fraction, it is common practice to rely on Markov chain Monte Carlo (MCMC) methods to sample from posterior distributions. Although computationally feasible, the iterative nature of MCMC often implies long sampling times to explore the target space with chains that may suffer from slow convergence and poor mixing. Furthermore, extra efforts have to be invested in diagnostic checks to monitor the reliability of the generated posterior samples. A sampling-free strategy for fast and flexible Bayesian inference in the mixture cure model is suggested in this article by combining Laplace approximations and penalized B-splines. A logistic regression model is assumed for the cure proportion and a Cox proportional hazards model with a P-spline approximated baseline hazard is used to specify the conditional survival function of susceptible subjects. Laplace approximations to the posterior conditional latent vector are based on analytical formulas for the gradient and Hessian of the log-likelihood, resulting in a substantial speed-up in approximating posterior distributions. The spline specification yields smooth estimates of survival curves and functions of latent variables together with their associated credible interval are estimated in seconds. A fully stochastic algorithm based on a Metropolis-Langevin-within-Gibbs sampler is also suggested as an alternative to the proposed Laplacian-P-splines mixture cure (LPSMC) methodology. The statistical performance and computational efficiency of LPSMC is assessed in a simulation study. Results show that LPSMC is an appealing alternative to MCMC for approximate Bayesian inference in standard mixture cure models. Finally, the novel LPSMC approach is illustrated on three applications involving real survival data.

PMID:35699121 | DOI:10.1002/sim.9373

Int Rev Psychiatry. 2022 Feb 17;34(2):128-139. doi: 10.1080/09540261.2022.2061840. Epub 2022 May 22.

ABSTRACT

Increases in youth psychiatric presentations to out-patient and emergency department settings during COVID-19 have been reported. This study, using data from five hospitals in Ireland, examines changes in the number and type of paediatric admissions during COVID-19 (March 2020 – February 2021) compared to the previous two years. ICD-10 classification was used to establish admissions with mental, behavioural, neuro-developmental disorders and psychosocial reasons (MBN-PS). Overall hospital admissions fell by 25.3%, while MBN-PS fell by only 2.6%, mostly during an initial lockdown. Admissions for MBN-PS increased in July-August (9.2%), increased further in September-December (28.3%), returning to pre-COVID-19 levels in January-February 2021. Significant increases were observed among youths with anorexia nervosa (47.8%), other eating disorders (42.9%), and admissions for anxiety (29.6%), with these effects relating to females only. Although admissions for self-harm increased (3%) and rates of ASD admissions reduced (17%), these were not statistically significant. The disproportionate increase in admissions for MBN-PS compared to medical admissions suggests an adverse effect of COVID-19 on youth mental health, for females in particular, and supports previous reports of a pandemic specific increase in eating psychopathology. Combined community and acute service delivery and capacity planning are urgently needed given the prior underfunding of services pre-pandemic.

PMID:35699100 | DOI:10.1080/09540261.2022.2061840

Int Rev Psychiatry. 2022 Feb 17;34(2):154-167. doi: 10.1080/09540261.2022.2072193. Epub 2022 May 12.

ABSTRACT

Chromatin remodelling is an important process in neural development and is related to autism spectrum disorder (ASD) and schizophrenia (SCZ) aetiology. To further elucidate the involvement of chromatin remodelling genes in the genetic aetiology of ASD and SCZ in the Japanese population, we performed a case-control study. Targeted sequencing was conducted on coding regions of four BAF chromatin remodelling complex genes: SMARCA2, SMARCA4, SMARCC2, and ARID1B in 185 ASD, 432 SCZ patients, and 517 controls. 27 rare non-synonymous variants were identified in ASD and SCZ patients, including 25 missense, one in-frame deletion in SMRACA4, and one frame-shift variant in SMARCC2. Association analysis was conducted to investigate the burden of rare variants in BAF genes in ASD and SCZ patients. Significant enrichment of rare missense variants in BAF genes, but not synonymous variants, was found in ASD compared to controls. Rare pathogenic variants indicated by in silico tools were significantly enriched in ASD, but not statistically significant in SCZ. Pathogenic-predicted variants were located in disordered binding regions and may confer risk for ASD and SCZ by disrupting protein-protein interactions. Our study supports the involvement of rare missense variants of BAF genes in ASD and SCZ susceptibility.

PMID:35699097 | DOI:10.1080/09540261.2022.2072193

Clin Exp Rheumatol. 2022 Jun 13. doi: 10.55563/clinexprheumatol/077ul6. Online ahead of print.

ABSTRACT

OBJECTIVES: To evaluate the effect of potential confounders on the association between sex and disease impact in recent-onset psoriatic arthritis.

METHODS: We performed a multicentre observational prospective study (2-year follow-up, regular annual visits). The study population comprised patients aged ≥18 years who fulfilled the CASPAR criteria and less than 2 years since the onset of symptoms. The dataset was generated using data for each patient at the 3 visits (baseline, first year, and second year of follow-up) matched with the PsAID values at each of the 3 visits. Once variables associated with both PsAID ≥4 and sex were selected, those that led to a difference of >10% between the adjusted and crude estimations were identified as potential confounders in the association between sex and PsAID. Lastly, the final multivariate logistic regression model estimating the association between sex and PsAID was defined.

RESULTS: The dataset contained 418 observations (158 at baseline, 135 at the first follow-up visit, and 125 at the second visit). The confounders identified in the multivariate model were HAQ, global pain, level of physical activity, and joint pattern at diagnosis. After adjustment for these variables, no statistically significant association was observed between female sex and PsAID ≥4.

CONCLUSIONS: The association between female sex and greater disease impact could be explained by the influence of other variables, specifically higher HAQ score, greater intensity of pain, differences in the level of physical activity and in the joint pattern at diagnosis (lower frequency of the spondylitis pattern in women).

PMID:35699067 | DOI:10.55563/clinexprheumatol/077ul6

Clin Exp Rheumatol. 2022 Jun 6. doi: 10.55563/clinexprheumatol/1shqmz. Online ahead of print.

ABSTRACT

OBJECTIVES: Behçet’s syndrome (BS) has been reported with cardiovascular involvement. It’s still unclear that BS is associated with the increased risk of ischaemic heart disease (IHD). We aimed to conduct a meta-analysis concerning the incidence of IHD in BS and identify the relationship between IHD and BS.

METHODS: We performed a comprehensive literature search based on PubMed and Embase databases up to 7 July, 2021. Incidence of IHD was calculated by metaproportion. Pooled risk ratio and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method of DerSimonian and Laird.

RESULTS: Four studies with 9237 patients with IHD in BS and 40353 controls were identified and included in our meta-analysis. The pooled risk ratio of IHD in patients with BS was 1.30 and achieved statistical significance (95% CI 1.04-1.64). The statistical heterogeneity was low with an I2 of 39% (p=0.18).

CONCLUSIONS: In this meta-analysis the presence of BS was associated with an increased risk of IHD. Prospective researches should be done to determine the pathophysiological and prognostic implications of increased IHD in BS.

PMID:35699061 | DOI:10.55563/clinexprheumatol/1shqmz

J Endourol. 2022 Jun 14. doi: 10.1089/end.2021.0811. Online ahead of print.

ABSTRACT

INTRODUCTION: For treatment of nephrolithiasis, ambulatory percutaneous nephrolithotomy (aPCNL) is growing in popularity for select patients. The aim of this study was to investigate the safety and efficacy of a set of aPCNL selection criteria as well as search for predictors of failed aPCNL resulting in inpatient admission.

METHODS AND MATERIALS: We reviewed all PCNL patients from 2016-2020. A total of 175 met selection criteria for aPCNL and were included. Primary outcome was safety and efficacy, and secondary outcome was to identify predictors of inpatient stay. Demographic and peri-operative data were analyzed with both descriptive and inferential statistics.

RESULTS: In total, between 2016-2020, 552 patients underwent PCNL, with 175 of them meeting criteria for aPCNL. 134/175 (76.6%) of these patients were successfully discharged the same day as the surgery and 41 patients were admitted. On univariate analysis, patients who required upper pole access or multiple accesses, (p=0.038) ASA>2 (p=0.005), or postoperative nephrostomy tube (PCN) (p<0.001) were more likely to be admitted after surgery. On multivariate analysis, only postoperative PCN was significantly associated with admission (p=0.015). Regarding reasons for unsuccessful aPCNL, 19.5% of admissions were attributed to intraoperative complications, 7% to social causes, 12.2% to postoperative complications, 14.6% to uncontrolled pain, and 34.1% to unexpected intraoperative procedures.

CONCLUSIONS: Ambulatory PCNL using selection criteria is safe and effective, with postoperative PCN predicting the possible necessity for conversion to inpatient admission. Furthermore, our study provides a practical algorithm for those opting to provide ambulatory PCNL to patients.

PMID:35699065 | DOI:10.1089/end.2021.0811

Clin Exp Rheumatol. 2022 Jun 13. doi: 10.55563/clinexprheumatol/ryp027. Online ahead of print.

ABSTRACT

OBJECTIVES: Fibromyalgia (FM) is a syndrome of unknown aetiology characterised by chronic widespread musculoskeletal pain and associated with high rates of psychiatric comorbidities, mainly mood and anxiety disorders.This study aims to determine the age at onset (AAO) and temporal sequencing patterns of FM and its frequent and distinguishable psychiatric comorbidities, the major depressive episode/s (MDE), and panic disorder (PD).

METHODS: Diagnosis of MDE and PD were assigned using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders fourth edition (DSM-IV). The AAO of FM, MDE, and PD was defined using the event history calendar. All patients completed a sociodemographic data form, self-report questionnaires measuring FM-related symptoms and function, and the Childhood Trauma Questionnaire-28 (CTQ-28).

RESULTS: 98 (83%) of the 118 recruited patients with FM had at least one psychiatric comorbidity. Two main temporal patterns were identified among the 83 patients (70.3 %) who could reliably report the age at onset of FM and psychiatric comorbidities. In the concurrent comorbidity pattern (CCP), MDE and/or PD co-occurred with the onset of FM. In the sequential pattern (SP), the patients first developed PD, then MDE, and finally FM. FM patients with SP are overweight and younger than those with a CCP (FM concurrent with MDE and PD) and reported more childhood adversities, mainly sexual abuse. AAO of psychiatric comorbidities significantly differed between the two patterns.

CONCLUSIONS: The presence of different temporal comorbidity patterns may suggest prevention/early treatment interventions, especially in patients with childhood adversities and early-onset PD.

PMID:35699055 | DOI:10.55563/clinexprheumatol/ryp027

Arch Bronconeumol. 2021 Oct;57(10):630-636. doi: 10.1016/j.arbr.2020.11.020.

ABSTRACT

BACKGROUND: COPD is a multifactorial disease which causes considerable mortality and morbidity worldwide. Previous studies assessing the possible relationship between indoor radon exposure and COPD have shown inconclusive results.

METHODS: A multicentric, hospital-based, case-control study was conducted in a Spanish radon-prone area. COPD cases were confirmed by spirometry and controls were selected due to trivial surgery or procedures not related to tobacco consumption. All participants had to have lived for at least 15 years in the same dwelling. Radon measurements were conducted individually in dwellings using alpha-track detectors. Results were obtained using multivariate logistic regression.

RESULTS: 189 cases and 747 controls took part. There was no significant association between residential radon concentrations and COPD onset with a OR of 1.12 (95%CI 0.41-3.06) for individuals exposed to more than 200Bq/m³ compared to those exposed to less than 50Bq/m³. Heavy smokers seem to increase their COPD risk if exposed to higher radon concentrations vs those exposed to lower concentrations. There was a statistically significant synergy index between radon exposure and tobacco consumption, S-index 11.60 (95%CI 3.71-36.26). Indoor radon concentration was higher in never/light smokers with COPD compared to controls.

CONCLUSIONS: No association between indoor radon and COPD has been observed. However, there might be some effect modification on the COPD risk in heavy smokers when high radon exposure is present. This is supported by the additive synergy observed. Also, a possible association between indoor radon and COPD onset in never and light smokers needs to be further studied.

PMID:35699045 | DOI:10.1016/j.arbr.2020.11.020

Arch Bronconeumol. 2021 Aug;57(8):521-527. doi: 10.1016/j.arbr.2020.03.033.

ABSTRACT

INTRODUCTION: Lung cancer screening with low-dose computed tomography (LDCT) has been proposed as a strategy to reduce lung cancer mortality. Since LDCT has side effects there is a need to carefully select the target population for screening programmes. Because in Spain health competences are transferred to the seventeen Autonomous Communities (ACs), the present paper aims to identify individuals at high risk of developing lung cancer in the different ACs.

METHODS: We used the 2011-2012 data of the Spanish National Interview Health Survey (n=21,006) to estimate the proportion of individuals at high risk of developing lung cancer using a 6-year prediction model (PLCO_m2012). This proportion was then extrapolated into absolute figures for the Spanish population, using the population census data of 2018 from the National Institute of Statistics.

RESULTS: The proportion of individuals aged 50-74 with a risk of lung cancer ≥2% was 9.5% (15.9% in men, 3.5% in women). This proportion ranged from 6.6% in Región de Murcia to 12.7% in Andalucía and 13.0% in Extremadura. When extrapolated to the Spanish population, it was estimated that a total of 1,341,483 individuals may have a 6-year risk of lung cancer ≥2%.

CONCLUSIONS: The present study is the first one that evaluated the number of individuals at high risk of developing lung cancer in the different Spanish ACs using a prediction model and selecting people with a 6-year risk ≥2%. Further studies should assess the cost and effectiveness associated to the implementation of a lung cancer screening programme to such population.

PMID:35699029 | DOI:10.1016/j.arbr.2020.03.033