Restricted maximum likelihood estimation of genetic parameters accounting for genomic relationships has been reported to impose computational burdens which typically are many times higher than those of corresponding analyses considering pedigree based relationships only. This can be attributed to the dense nature of genomic relationship matrices and their inverses. We outline a reparameterisation of the multivariate linear mixed model to principal components and its effects on the sparsity pattern of the pertaining coefficient matrix in the mixed model equations. Using two data sets we demonstrate that this can dramatically reduce the computing time per iterate of the widely used 'average information' algorithm for restricted maximum likelihood. This is primarily due to the fact that on the principal component scale, the first derivatives of the coefficient matrix with respect to the parameters modelling genetic covariances between traits are independent of the relationship matrix between individuals, i.e. are not afflicted by a multitude of genomic relationships.
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http://dx.doi.org/10.1186/s12711-023-00781-7 | DOI Listing |
JAMA Health Forum
January 2025
Division of General Internal Medicine and Primary Care, Brigham and Women's Hospital, Boston, Massachusetts.
Importance: Although Medicare Advantage plans frequently offer dental benefits, enrollees report lower rates of dental care use and higher rates of unmet dental need compared with individuals with employer-sponsored benefits. It is unknown which attributes of Medicare Advantage dental plans are associated with enhanced dental care access.
Objective: To determine attributes of Medicare Advantage dental plans associated with higher rates of dental care use and lower rates of unmet dental need.
Stat Med
February 2025
Medical University of South Carolina, Charleston, South Carolina, USA.
This manuscript derives the allocation predictability measured by the correct guess probability and the probability of being deterministic for individual treatment assignments, as well as the averages of a randomization sequence, based on the treatment imbalance transition matrix and the conditional allocation probability. The methods described are applicable to restricted randomization designs that satisfy the following criteria: (1) two-arm equal allocation, (2) restriction of maximum tolerated imbalance, and (3) conditional allocation probability fully determined by the observed current treatment imbalance. Analytical results indicate that, for two-arm equal allocation trials, allocation predictability alternates by the odd/even sequence order of the treatment assignment.
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January 2025
Division of Respirology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
Background: Pericardial complications following cardiac surgery are common and debilitating, significantly impacting patients' survival. We performed this network meta-analysis to identify the most effective and safest preventions and treatments for pericardial complications following cardiac surgery.
Methods: We systematically searched PubMed/MEDLINE, EMBASE and Cochrane CENTRAL from inception to 22 January 2024.
Lancet Reg Health West Pac
January 2025
Department of Epidemiology & Biostatistics, School of Public Health, Peking University, Beijing 100191, China.
Background: Existing studies have not provided robust evidence about the CVD risk of non-smoking patients with restrictive spirometric pattern (RSP) or airflow obstruction (AFO), and how the risk is modified by body shape. We aimed to bridge the gap.
Methods: We used never-smokers' data from the China Kadoorie Biobank (CKB) and performed Cox models by sex (278,953 females and 50,845 males).
Front Public Health
January 2025
Institute of Physical Education, Shanxi University, Taiyuan, China.
Objective: The objective of this study is to compare the effectiveness of low-load blood flow restriction training (LL-BFRT) to heavy-load resistance training (HL-RT) in male collegiate athletes with chronic non-specific low back pain (CNLBP).
Methods: Twenty-six participants were randomly assigned to LL-BFRT ( = 13) or HL-RT ( = 13). All participants supervised exercises (deep-squat, lateral pull-down, bench-press and machine seated crunch) cycled 4 times per week for 4 weeks (16 sessions).
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