Autoregressive errors with a repeated measures design in clinical trials

1986 ◽  
Vol 7 (2) ◽  
pp. 149-164
Author(s):  
Curtis K. Church ◽  
James R. Schwenke
Keyword(s):  
Clinical Trials ◽  
Repeated Measures ◽  
Repeated Measures Design ◽  
Autoregressive Errors

Is a Picture Worth a Thousand Medical Words? A Randomized Trial of Reporting Formats for Medical Research Data

1991 ◽  
Vol 30 (02) ◽  
pp. 145-150 ◽  
Author(s):  
L. S. Elting ◽  
G. P. Bodey
Keyword(s):  
Clinical Trials ◽  
Randomized Trial ◽  
Repeated Measures ◽  
Time Dependent ◽  
Medical Settings ◽  
Repeated Measures Design ◽  
Valuable Method ◽  
The Status ◽  
The Individual ◽  
Pie Chart

AbstractMonitoring data that vary over time is an essential component of medical practice. This is doubly true in clinical trials in which the overall safety and efficacy of investigational treatments in populations must be monitored in addition to the status of the individual patients who receive them. We report the results of a randomized trial of four reporting methods for time-dependent information derived from clinical trials; narrative text, table, pie chart and icon. Multivariate analysis of variance with a repeated measures design was used to analyze the efficiency of subjects’ (physicians, research nurses and laboratory personnel) assimilation of information. Icons were found to be superior to the other reporting formats tested in both speed (p <0.0001) and accuracy (p = 0.02). The differences were most pronounced in subjects’ first exposure to the data, suggesting that icons reduce the time needed for training. We conclude that icons are a valuable method for presentation of time-dependent information in medical settings.

Power of Modified Brown-Forsythe and Mixed-Model Approaches in Split-Plot Designs

Methodology ◽  
2017 ◽  
Vol 13 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Pablo Livacic-Rojas ◽  
Guillermo Vallejo ◽  
Paula Fernández ◽  
Ellián Tuero-Herrero
Keyword(s):  
Repeated Measures ◽  
Statistical Power ◽  
Mixed Model ◽  
Covariance Structure ◽  
Simulation Method ◽  
Future Research ◽  
Repeated Measures Design ◽  
Fixed And Random Effects ◽  
Split Plot ◽  
High Level

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.

Lifestyle intervention using modified BASNEF model in hypertension management (Preprint)

2020 ◽  
Author(s):  
Resti Tito Villarino ◽  
Christopher Arcay ◽  
Maria Concepcion Temblor
Keyword(s):  
Lifestyle Intervention ◽  
Repeated Measures ◽  
Intervention Program ◽  
Phase 1 ◽  
Management Technique ◽  
Enabling Factors ◽  
Educational Models ◽  
Stroke Risk Factor ◽  
Repeated Measures Design ◽  
Lifestyle Intervention Program

BACKGROUND Hypertension is a serious health issue and a major cardiovascular disease and stroke risk factor. In hypertensive patients, various health educational models have been used to improve their lifestyle, but the findings are inconsistent. OBJECTIVE The study assessed the effects of a lifestyle intervention program using modified Beliefs, Attitude, Subjective Standards, Enabling Factors (BASNEF) model among non-adherent hypertensive respondents in relation to the introduction of a lifestyle intervention program in the management of hypertension. METHODS This is a quantitative quasi-experimental research particularly utilizing a repeated-measures design of within-subjects approach on the 50 non-adherent patients diagnosed with essential hypertension at Moalboal, Cebu, Philippines in 2019. The respondents received five sessions of trainings based on modified BASNEF model. The Morisky Medication Adherence instrument was used. The first phase included a demographic questionnaire and the last phase comprised the evaluation of the program. Frequencies, percentages, means and standard deviations for descriptive statistics while t-test, repeated measures, ANOVA, and Pearson product moment correlation for inferential statistics. RESULTS The result indicated that the phase 1 mean (146.5) of the systolic readings differ significantly from the phase 4 mean (134.92) of the systolic readings. However, since these two means came from phases that were not consecutive, the result, as a whole, did not show a significant decrease or change when analyzed chronologically from one phase to the next. CONCLUSIONS The study has established that BASNEF model approach can be an effective BP management technique.

Effectiveness of a Care Delivery Model for High-Need Older Adults in Communities

2020 ◽  
pp. 104973152098235
Author(s):  
Kuei-Min Chen ◽  
Hui-Fen Hsu ◽  
Li-Yen Yang ◽  
Chiang-Ching Chang ◽  
Yu-Ming Chen ◽  
...  
Keyword(s):  
Older Adults ◽  
Repeated Measures ◽  
Comparison Group ◽  
Care Delivery ◽  
Intervention Group ◽  
Community Dwelling ◽  
Delivery Model ◽  
Positive Effects ◽  
Repeated Measures Design ◽  
Care Delivery Model

Purpose: This study aimed to test the effectiveness of High-Need Community-Dwelling Older Adults Care Delivery Model (HCOACDM) in Taiwan. Methods: A cluster randomized controlled trial with repeated measures design was conducted in eight community care centers, involving 145 high-need older adults who were assigned to the intervention group or comparison group. The HCOACDM was provided over 6 months. Functional ability, quality of life, depressive symptoms, and health care and social service utilizations were measured at baseline, at 3 months, and 6 months into the intervention. The participants’ satisfaction was measured at the end of 6-month intervention. Results: Positive effects were shown on all variables in the intervention group at both the 3-month and 6-month intervals (all p < .05). The intervention group had a higher satisfaction with care delivery than the comparison group ( p < .05). Discussion: The promising findings supported a long-term implementation of the HCOACDM as applicable and beneficial.

scholarly journals Estimating and reporting treatment effects in clinical trials for weight management: using estimands to interpret effects of intercurrent events and missing data

2021 ◽  
Author(s):  
Sean Wharton ◽  
Arne Astrup ◽  
Lars Endahl ◽  
Michael E. J. Lean ◽  
Altynai Satylganova ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Missing Data ◽  
Weight Management ◽  
Treatment Effect ◽  
Repeated Measures ◽  
Treatment Effects ◽  
Randomized Clinical Trials ◽  
Weight Losses ◽  
The Difference ◽  
Treatment Of Obesity

AbstractIn the approval process for new weight management therapies, regulators typically require estimates of effect size. Usually, as with other drug evaluations, the placebo-adjusted treatment effect (i.e., the difference between weight losses with pharmacotherapy and placebo, when given as an adjunct to lifestyle intervention) is provided from data in randomized clinical trials (RCTs). At first glance, this may seem appropriate and straightforward. However, weight loss is not a simple direct drug effect, but is also mediated by other factors such as changes in diet and physical activity. Interpreting observed differences between treatment arms in weight management RCTs can be challenging; intercurrent events that occur after treatment initiation may affect the interpretation of results at the end of treatment. Utilizing estimands helps to address these uncertainties and improve transparency in clinical trial reporting by better matching the treatment-effect estimates to the scientific and/or clinical questions of interest. Estimands aim to provide an indication of trial outcomes that might be expected in the same patients under different conditions. This article reviews how intercurrent events during weight management trials can influence placebo-adjusted treatment effects, depending on how they are accounted for and how missing data are handled. The most appropriate method for statistical analysis is also discussed, including assessment of the last observation carried forward approach, and more recent methods, such as multiple imputation and mixed models for repeated measures. The use of each of these approaches, and that of estimands, is discussed in the context of the SCALE phase 3a and 3b RCTs evaluating the effect of liraglutide 3.0 mg for the treatment of obesity.

scholarly journals The Acute Effects of a Swimming Session on the Shoulder Rotators Strength and Balance of Age Group Swimmers

2021 ◽  
Vol 18 (15) ◽  
pp. 8109
Author(s):  
Nuno Batalha ◽  
Jose A. Parraca ◽  
Daniel A. Marinho ◽  
Ana Conceição ◽  
Hugo Louro ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Training Session ◽  
Age Group ◽  
Acute Effects ◽  
Muscle Strengthening ◽  
Repeated Measures Design ◽  
Before And After ◽  
Shoulder Strength ◽  
Isometric Torque ◽  
Gender Specific

The purpose of this study was to analyze the acute effects of a standardized water training session on the shoulder rotators strength and balance in age group swimmers, in order to understand whether a muscle-strengthening workout immediately after the water training is appropriate. A repeated measures design was implemented with two measurements performed before and after a standardized swim session. 127 participants were assembled in male (n = 72; age: 16.28 ± 1.55 years, height: 174.15 ± 7.89 cm, weight: 63.97 ± 6.51 kg) and female (n = 55; age: 15.29 ± 1.28 years, height: 163.03 ± 7.19 cm, weight: 52.72 ± 5.48 kg) cohorts. The isometric torque of the shoulder internal (IR) and external (ER) rotators, as well as the ER/IR ratios, were assessed using a hand-held dynamometer. Paired sample t-tests and effect sizes (Cohen’s d) were used (p ≤ 0.05). No significant differences were found on the shoulder rotators strength or balance in males after training. Females exhibited unchanged strength values after practice, but there was a considerable decrease in the shoulder rotators balance of the non-dominant limb (p < 0.01 d = 0.366). This indicates that a single practice seems not to affect the shoulders strength and balance of adolescent swimmers, but this can be a gender specific phenomenon. While muscle-strengthening workout after the water session may be appropriate for males, it can be questionable regarding females. Swimming coaches should regularly assess shoulder strength levels in order to individually identify swimmers who may or may not be able to practice muscle strengthening after the water training.

scholarly journals The use of multiple-criteria decision-making theory to measure students’ perceptions of high-fidelity simulation

2017 ◽  
Vol 3 (3) ◽  
pp. 88-93 ◽  
Author(s):  
Maureen Anne Jersby ◽  
Paul Van-Schaik ◽  
Stephen Green ◽  
Lili Nacheva-Skopalik
Keyword(s):  
Decision Making ◽  
Clinical Practice ◽  
Repeated Measures ◽  
Clinical Decision Making ◽  
Learning Experience ◽  
Clinical Decision ◽  
High Fidelity ◽  
High Fidelity Simulation ◽  
Initial Exposure ◽  
Repeated Measures Design

BackgroundHigh-Fidelity Simulation (HFS) has great potential to improve decision-making in clinical practice. Previous studies have found HFS promotes self-confidence, but its effectiveness in clinical practice has not been established. The aim of this research is to establish if HFS facilitates learning that informs decision-making skills in clinical practice using MultipleCriteria DecisionMaking Theory (MCDMT).MethodsThe sample was 2nd year undergraduate pre-registration adult nursing students.MCDMT was used to measure the students’ experience of HFS and how it developed their clinical decision-making skills. MCDMT requires characteristic measurements which for the learning experience were based on five factors that underpin successful learning, and for clinical decision-making, an analytical framework was used. The study used a repeated-measures design to take two measurements: the first one after the first simulation experience and the second one after clinical placement. Baseline measurements were obtained from academics. Data were analysed using the MCDMT tool.ResultsAfter their initial exposure to simulation learning, students reported that HFS provides a high-quality learning experience (87%) and supports all aspects of clinical decision-making (85%). Following clinical practice, the level of support for clinical decision-making remained at 85%, suggesting that students believe HFS promotes transferability of knowledge to the practice setting.ConclusionOverall, students report a high level of support for learning and developing clinical decision-making skills from HFS. However, there are no comparative data available from classroom teaching of similar content so it cannot be established if these results are due to HFS alone.

scholarly journals Test–retest reliability of laser evoked pain perception and fMRI BOLD responses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yanzhi Bi ◽  
Xin Hou ◽  
Jiahui Zhong ◽  
Li Hu
Keyword(s):  
Resting State ◽  
Repeated Measures ◽  
Subjective Experience ◽  
Pain Perception ◽  
Primary Motor Cortex ◽  
Intraclass Correlation ◽  
Retest Reliability ◽  
Repeated Measures Design ◽  
Brain Responses ◽  
Test Retest Reliability

AbstractPain perception is a subjective experience and highly variable across time. Brain responses evoked by nociceptive stimuli are highly associated with pain perception and also showed considerable variability. To date, the test–retest reliability of laser-evoked pain perception and its associated brain responses across sessions remain unclear. Here, an experiment with a within-subject repeated-measures design was performed in 22 healthy volunteers. Radiant-heat laser stimuli were delivered on subjects’ left-hand dorsum in two sessions separated by 1–5 days. We observed that laser-evoked pain perception was significantly declined across sessions, coupled with decreased brain responses in the bilateral primary somatosensory cortex (S1), right primary motor cortex, supplementary motor area, and middle cingulate cortex. Intraclass correlation coefficients between the two sessions showed “fair” to “moderate” test–retest reliability for pain perception and brain responses. Additionally, we observed lower resting-state brain activity in the right S1 and lower resting-state functional connectivity between right S1 and dorsolateral prefrontal cortex in the second session than the first session. Altogether, being possibly influenced by changes of baseline mental state, laser-evoked pain perception and brain responses showed considerable across-session variability. This phenomenon should be considered when designing experiments for laboratory studies and evaluating pain abnormalities in clinical practice.

scholarly journals Empowering traditional birth attendants as agents of maternal and neonatal immunization uptake in Nigeria: a repeated measures design

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chinedu Anthony Iwu ◽  
Kenechi Uwakwe ◽  
Uche Oluoha ◽  
Chukwuma Duru ◽  
Ernest Nwaigbo
Keyword(s):  
Rural Communities ◽  
Rural Areas ◽  
Repeated Measures ◽  
Average Length ◽  
Traditional Birth Attendants ◽  
Post Intervention ◽  
Repeated Measures Design ◽  
Birth Attendants ◽  
Culturally Adapted ◽  
Workshop Intervention

Abstract Background Adequate immunization coverage in rural communities remain a challenge in Nigeria. Traditional birth attendants (TBAs) form an integral part of the social, cultural and religious fabric in most rural communities in Nigeria. Despite their limitations in handling the complications of childbirth, TBAs are widely accepted and patronized, especially in rural areas. The objectives of the project were to empower TBAs and assess the use of a culturally adapted audio-visual workshop intervention to change their knowledge, attitude and willingness to promote immunization uptake. Methods A repeated-measures design that used a convenience sampling technique to select 90 TBAs from the three geopolitical zones of Imo State, Nigeria. The TBAs were engaged through a culturally adapted audio-visual workshop. Data were collected before and immediately after intervention using a pretested questionnaire. Chi square test was done to determine any significant association with the zone of practice and paired sample t-test analysis to determine any significant pre and post intervention change. Level of significance was set at p ≤ ·05. Results More than half of the TBAs had at most, a secondary level of education (54·4%). The average length of time they practiced as TBAs was 16 years with an average of ten birth deliveries per month. After the intervention, all the respondents (100%) reported a willingness to always promote immunization uptake and also, there was a statistically significant increase in Knowledge (p < ·000). Similarly, the level of knowledge in the post intervention period appeared to be significantly associated with the zone of practice (p = ·027). Conclusion The workshop intervention empowered the TBAs irrespective of their zones of residence by successfully improving their knowledge, though at varying levels; and consequently, their willingness to always promote immunization uptake.

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