The Analysis of Repeated Measures and other Mixed-Model ANOVA Designs

1972 ◽  
Vol 6 (2) ◽  
pp. 185-188 ◽  
Author(s):  
Kenneth D. Hopkins ◽  
Gene V Glass
2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 253-253
Author(s):  
Cherrie Nolden ◽  
Matt Akins ◽  
Abbey Grisham ◽  
Dan Schaefer ◽  
Mark Cook

Abstract Eimeria prevention in dairy heifers is challenging. Possible tools beyond the common practice of feeding an ionophore include polyphenolic compounds in essential oils (cinnamaldehyde, thymol, oregano oil) and binding interleukin-10 (IL-10) to reduce Eimeria’s host immunotolerance strategy. Holstein heifers (160 total; 12–14 wk old) were randomly assigned to one of 5 treatments: 160 mg/head/d of sodium monensin (MON), 1100 mg/head/d of antibody to IL-10 during wk 3–4 (aIL-10), 10 g/head/d of a blend of essential oils (EO), egg control without antibodies to IL-10 (EC), or negative control (NC). Calves were grouped 8 per pen with 4 blocks of 5 pens and FEC averaged by pen before analysis. We evaluated treatment effects on the fecal egg counts (FEC) of E. bovis, E. zurnii and E. auburnesis. Fecal counts were conducted biweekly using FLOTAC technique for 10 wk. Effects were analyzed with a mixed model ANOVA in SAS with repeated measures and ranked for normality. Total FEC prevalence was absent at wk 0, with greater prevalence at wk 4 and 6 for all treatments except MON (P < 0.05), and there were no differences among treatments in positive prevalence by wk 8 and 10 (P > 0.10). There was no difference between NC and MON treatments for wk 6, 8 and 10 in E. bovis, wk 2 and 4 for E. zurnii, and wk 2 and 4 for E. auburnesis (P > 0.05), which is evidence of reduced monensin efficacy or excessive environmental Eimeria load. EO and aIL-10 FEC were also not different than MON counts at multiple timepoints (P > 0.05). Overall, this shows potential monensin resistance after extended exposure (6–8 wk) to high environmental loads of Eimeria and similar FEC between monensin treated calves and those treated with EO or aIL-10.


2020 ◽  
Vol 29 (3) ◽  
pp. 391-403
Author(s):  
Dania Rishiq ◽  
Ashley Harkrider ◽  
Cary Springer ◽  
Mark Hedrick

Purpose The main purpose of this study was to evaluate aging effects on the predominantly subcortical (brainstem) encoding of the second-formant frequency transition, an essential acoustic cue for perceiving place of articulation. Method Synthetic consonant–vowel syllables varying in second-formant onset frequency (i.e., /ba/, /da/, and /ga/ stimuli) were used to elicit speech-evoked auditory brainstem responses (speech-ABRs) in 16 young adults ( M age = 21 years) and 11 older adults ( M age = 59 years). Repeated-measures mixed-model analyses of variance were performed on the latencies and amplitudes of the speech-ABR peaks. Fixed factors were phoneme (repeated measures on three levels: /b/ vs. /d/ vs. /g/) and age (two levels: young vs. older). Results Speech-ABR differences were observed between the two groups (young vs. older adults). Specifically, older listeners showed generalized amplitude reductions for onset and major peaks. Significant Phoneme × Group interactions were not observed. Conclusions Results showed aging effects in speech-ABR amplitudes that may reflect diminished subcortical encoding of consonants in older listeners. These aging effects were not phoneme dependent as observed using the statistical methods of this study.


Methodology ◽  
2017 ◽  
Vol 13 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Pablo Livacic-Rojas ◽  
Guillermo Vallejo ◽  
Paula Fernández ◽  
Ellián Tuero-Herrero

Abstract. Low precision of the inferences of data analyzed with univariate or multivariate models of the Analysis of Variance (ANOVA) in repeated-measures design is associated to the absence of normality distribution of data, nonspherical covariance structures and free variation of the variance and covariance, the lack of knowledge of the error structure underlying the data, and the wrong choice of covariance structure from different selectors. In this study, levels of statistical power presented the Modified Brown Forsythe (MBF) and two procedures with the Mixed-Model Approaches (the Akaike’s Criterion, the Correctly Identified Model [CIM]) are compared. The data were analyzed using Monte Carlo simulation method with the statistical package SAS 9.2, a split-plot design, and considering six manipulated variables. The results show that the procedures exhibit high statistical power levels for within and interactional effects, and moderate and low levels for the between-groups effects under the different conditions analyzed. For the latter, only the Modified Brown Forsythe shows high level of power mainly for groups with 30 cases and Unstructured (UN) and Autoregressive Heterogeneity (ARH) matrices. For this reason, we recommend using this procedure since it exhibits higher levels of power for all effects and does not require a matrix type that underlies the structure of the data. Future research needs to be done in order to compare the power with corrected selectors using single-level and multilevel designs for fixed and random effects.


2019 ◽  
Vol 24 (2) ◽  
pp. 200-208
Author(s):  
Ravindra Arya ◽  
Francesco T. Mangano ◽  
Paul S. Horn ◽  
Sabrina K. Kaul ◽  
Serena K. Kaul ◽  
...  

OBJECTIVEThere is emerging data that adults with temporal lobe epilepsy (TLE) without a discrete lesion on brain MRI have surgical outcomes comparable to those with hippocampal sclerosis (HS). However, pediatric TLE is different from its adult counterpart. In this study, the authors investigated if the presence of a potentially epileptogenic lesion on presurgical brain MRI influences the long-term seizure outcomes after pediatric temporal lobectomy.METHODSChildren who underwent temporal lobectomy between 2007 and 2015 and had at least 1 year of seizure outcomes data were identified. These were classified into lesional and MRI-negative groups based on whether an epilepsy-protocol brain MRI showed a lesion sufficiently specific to guide surgical decisions. These patients were also categorized into pure TLE and temporal plus epilepsies based on the neurophysiological localization of the seizure-onset zone. Seizure outcomes at each follow-up visit were incorporated into a repeated-measures generalized linear mixed model (GLMM) with MRI status as a grouping variable. Clinical variables were incorporated into GLMM as covariates.RESULTSOne hundred nine patients (44 females) were included, aged 5 to 21 years, and were classified as lesional (73%), MRI negative (27%), pure TLE (56%), and temporal plus (44%). After a mean follow-up of 3.2 years (range 1.2–8.8 years), 66% of the patients were seizure free for ≥ 1 year at last follow-up. GLMM analysis revealed that lesional patients were more likely to be seizure free over the long term compared to MRI-negative patients for the overall cohort (OR 2.58, p < 0.0001) and for temporal plus epilepsies (OR 1.85, p = 0.0052). The effect of MRI lesion was not significant for pure TLE (OR 2.64, p = 0.0635). Concordance of ictal electroencephalography (OR 3.46, p < 0.0001), magnetoencephalography (OR 4.26, p < 0.0001), and later age of seizure onset (OR 1.05, p = 0.0091) were associated with a higher likelihood of seizure freedom. The most common histological findings included cortical dysplasia types 1B and 2A, HS (40% with dual pathology), and tuberous sclerosis.CONCLUSIONSA lesion on presurgical brain MRI is an important determinant of long-term seizure freedom after pediatric temporal lobectomy. Pediatric TLE is heterogeneous regarding etiologies and organization of seizure-onset zones with many patients qualifying for temporal plus nosology. The presence of an MRI lesion determined seizure outcomes in patients with temporal plus epilepsies. However, pure TLE had comparable surgical seizure outcomes for lesional and MRI-negative groups.


BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dulanji K. Kuruppu ◽  
Joshua Tobin ◽  
Yan Dong ◽  
Sheena K. Aurora ◽  
Laura Yunes-Medina ◽  
...  

Abstract Background Galcanezumab is a calcitonin gene-related peptide (CGRP) monoclonal antibody (mAb) indicated for the preventive treatment of migraine. While galcanezumab has demonstrated efficacy in patients who did not respond to prior preventive medications in general, its efficacy in patients who did not benefit from individual, commonly prescribed preventive treatments due to inadequate efficacy or safety/tolerability remains unknown. Methods CONQUER was a 3-month, randomized, double-blind, placebo-controlled, phase 3b study that enrolled patients with episodic or chronic migraine who had 2 to 4 migraine preventive medication category failures in the past 10 years. Patients were randomly assigned 1:1 to receive placebo (N = 230) or galcanezumab 120 mg/month (240 mg loading dose; N = 232). Post hoc analyses were conducted to determine the efficacy of galcanezumab in patients who had not benefited from six of the most commonly prescribed migraine preventive medications. The mean change from baseline in monthly migraine headache days and ≥ 50 % response rates were assessed over months 1–3. Improvement in Migraine-Specific Questionnaire Role Function-Restrictive (MSQ-RFR) scores were assessed at month 3. The endpoints were estimated via mixed model with repeated measures. Results The most common treatment failures due to inadequate efficacy or safety/tolerability, which at least 20 % of patients reported trying without benefit, included topiramate, amitriptyline, propranolol, valproate or divalproex, onabotulinum toxin A, and metoprolol. Patients who had not previously benefited from these treatments had a greater mean reduction in monthly migraine headache days across months 1–3 in the galcanezumab group compared to placebo (all p < 0.01). More patients treated with galcanezumab experienced a ≥ 50 % reduction from baseline in monthly migraine headache days across months 1–3 compared to placebo (all p < 0.05). Galcanezumab-treated patients had a greater improvement in mean MSQ-RFR scores at month 3 compared to placebo (all p < 0.01). Conclusions In this population, galcanezumab was effective in reducing monthly migraine headache days, improving response rates, and enhancing quality of life in patients who had not previously benefited from topiramate, amitriptyline, propranolol, valproate or divalproex, onabotulinum toxin A, and/or metoprolol due to inadequate efficacy or safety/tolerability. Trial registration ClinicalTrials.gov NCT03559257 (CONQUER).


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 89-90
Author(s):  
Katy Brinkley-Bissinger ◽  
Laura M Cersosimo ◽  
Kathleen E Sullivan ◽  
Shannon E Livingston ◽  
Jill M Bobel ◽  
...  

Abstract Phosphorus in equine rations is supplied by inorganic mineral fortification or naturally-occurring P in forages and grains. Up to 70% of P in plant material is bound to phytate. In monogastrics like poultry and swine, phytate can reduce absorption of P and divalent cations, but the extent that this occurs in horses is unknown. This study tested the hypothesis that phytate decreases mineral digestibility in horses. Six mature Quarter Horse geldings (mean ± SE, 586 ± 19 kg, 10 ± 1.5 y) were randomly assigned to two treatments applied in a cross-over design: IP6 (Ca-Mg-phytate isolated from rice bran fed at 15 mg phytic acid/kg BW) or CON (equivalent Ca, Mg and P from inorganic minerals to match intake from IP6). The level of phytate added represented an amount present in grain-rich rations typically fed to broodmares, growing horses and performance athletes. Supplements were added to a basal diet (1.75% BW, DM basis) consisting of 75% timothy hay and 25% roughage-based concentrate. Each 14-d period had an 11-d treatment adaptation followed by a 3-d total fecal collection. After acid digestion, P was determined colorimetrically and other minerals were determined by inductively coupled plasma spectrometry. Data were analyzed using mixed model ANOVA. Intakes of Ca, P, Mg, Zn, Cu and Fe were similar between treatments (140, 72, 40, 1.05, 0.24, and 1.78 mg/kg BW respectively). Apparent P digestibility (18.8 and 17%, SEM 1.9; P = 0.41) and estimates of true P digestibility (32.8 and 30.8%, SEM 1.9; P = 0.39) were similar between CON and IP6. Apparent digestibilities of other minerals were also not affected by IP6 supplementation. Findings suggest horses have sufficient microbial phytase activity in the gastrointestinal tract to mitigate impacts of dietary phytate. Higher levels or different forms of phytate and marginal mineral intake may yield different results.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2827
Author(s):  
Fuengfa Khobkhun ◽  
Mark Hollands ◽  
Jim Richards

Difficulty in turning is prevalent in older adults and results in postural instability and risk of falling. Despite this, the mechanisms of turning problems have yet to be fully determined, and it is unclear if different speeds directly result in altered posture and turning characteristics. The aim of this study was to identify the effects of turning speeds on whole-body coordination and to explore if these can be used to help inform fall prevention programs in older adults. Forty-two participants (21 healthy older adults and 21 younger adults) completed standing turns on level ground. Inertial Measurement Units (XSENS) were used to measure turning kinematics and stepping characteristics. Participants were randomly tasked to turn 180° at one of three speeds; fast, moderate, or slow to the left and right. Two factors mixed model analysis of variance (MM ANOVA) with post hoc pairwise comparisons were performed to assess the two groups and three turning speeds. Significant interaction effects (p < 0.05) were seen in; reorientation onset latency of head, pelvis, and feet, peak segmental angular separation, and stepping characteristics (step frequency and step size), which all changed with increasing turn speed. Repeated measures ANOVA revealed the main effects of speeds within the older adults group on those variables as well as the younger adults group. Our results suggest that turning speeds result in altered whole-body coordination and stepping behavior in older adults, which use the same temporospatial sequence as younger adults. However, some characteristics differ significantly, e.g., onset latency of segments, peak head velocity, step frequency, and step size. Therefore, the assessment of turning speeds elucidates the exact temporospatial differences between older and younger healthy adults and may help to determine some of the issues that the older population face during turning, and ultimately the altered whole-body coordination, which lead to falls.


Author(s):  
Natasha Buitendag ◽  
Gail S. Fortuin ◽  
Amber De Laan

Background: Integrated reporting has attracted much attention in the past few years, and South Africa has taken the lead in its development worldwide. An annual survey is published by Ernst & Young regarding the quality of the integrated reports of the top 100 entities listed on the Johannesburg Stock Exchange (JSE).Aim: The study on which this article is based was aimed at determining whether the assessment of an entity’s characteristics can predetermine the quality of the integrated report generated by that entity. Setting: This article focuses on an analysis of the integrated reporting of the top 100 entities listed on JSE for the financial years ending in 2013, 2014 and 2015.Methods: Comparison of categorical variables, mixed-model repeated measures ANOVA and generalised estimating equations were applied to identify the best classificators to distinguish between excellent integrated reporting and those reports where progress could still be made. Results: The results show that the type of industry the entity finds itself in, the size and profitability of the entity, as well as the composition of the members of the board, have an effect on the quality of the integrated report.Conclusion: Our results indicated that the type of industry, size of an entity, the profitability and composition of the board of directors, all have an effect on the quality of the integrated reporting. Our evidence will assist current and prospective stakeholders in evaluating the expected quality of an entity’s integrated report, through the evaluation of certain firm characteristics.


2017 ◽  
Vol 41 (S1) ◽  
pp. S90-S91 ◽  
Author(s):  
C. Correll ◽  
R. Goldman ◽  
J. Cucchiaro ◽  
L. Deng ◽  
A. Loebel

IntroductionLurasidone is an atypical antipsychotic that demonstrated efficacy in the treatment of adults with schizophrenia in the dose range of 37–148 mg/day.Objective/AimsThe objective of this analysis was to evaluate the efficacy of lurasidone in adolescent patients with schizophrenia.MethodsAdolescents (13–17 years old) diagnosed with schizophrenia were randomly assigned to six weeks of double-blind treatment with lurasidone 37 mg/day, 74 mg/day or placebo. Changes from baseline to week 6 in PANSS total and subscale (positive, negative, general psychopathology, excitability) scores were evaluated using mixed-model repeated-measures analysis.ResultsA total of 326 patients (mean age, 15.4 years) were randomized and received lurasidone 37 mg/day (n = 108), 74 mg/day (n = 106), or placebo (n = 112). The PANSS total score at week 6 demonstrated a placebo-adjusted, least-squares (LS) mean improvement of –8.0 (P < 0.001; effect size [ES], 0.51) for the 37 mg/day group and –7.7 (P < 0.001; ES = 0.48) for the 74 mg/day group. Placebo-adjusted LS mean change for lurasidone 37 mg/day and 74 mg/day, respectively, was –3.2 (P < 0.001; ES = 0.62) and –3.2 (P < 0.001; ES = 0.60) on the PANSS positive subscale, –1.7 (P = 0.011; ES = 0.41) and –1.6 (P = 0.022; ES = 0.35) on the PANSS negative subscale, –2.8 (P = 0.012; ES = 0.38) and –2.8 (P = 0.011; ES = 0.37) on the PANSS general psychopathology subscale, and –1.1 (P = 0.016; ES = 0.36) and –1.8 (P < 0.001; ES = 0.53) on the PANSS excitability subscale.ConclusionsIn adolescent patients with schizophrenia, lurasidone (37 mg/day and 74 mg/day) demonstrated statistically significant efficacy and clinically meaningful improvement across a wide spectrum of symptoms associated with schizophrenia. Sponsored by Sunovion Pharmaceuticals Inc. ClinicalTrials.gov identifier: NCT01911429.Disclosure of interestDr Correll reports being a consultant and/or advisor for Alkermes, Forum Pharmaceuticals Inc., Gerson Lehrman Group, IntraCellular Therapies, Janssen/J&J, Lundbeck, Medavante, Medscape, Otsuka, Pfizer Inc, ProPhase, Sunovion Pharmaceuticals Inc., Supernus, Takeda, and Teva providing expert testimony for Bristol-Myers Squibb Company, Janssen, and Otsuka serving on a Data Safety Monitoring Board for Lundbeck and Pfizer Inc and receiving grant support from Takeda. Drs Goldman, Cucchiaro, Deng and Loebel are employees of Sunovion Pharmaceuticals Inc.


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