Sample size calculations based on day-to-day variability of stress biomarkers in persons with dementia and their family caregivers

Introduction: Accurate estimates of intra-individual variability are necessary for proper design of clinical trials and epidemiological studies where the stress biomarkers cortisol and dehydroepiandrosterone sulfate (DHEA-S) are measured for dyads of persons with dementia (PWDs) and their family car...

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Main Authors: Azita Emami, Jeehye Jun, Gabriella Engström, Lars Berglund, Töres Theorell
Format: Article
Language:English
Published: Tabriz: Hamid Allahverdipour, 2024- 2024-11-01
Series:BioSocial Health Journal
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Online Access:https://biosocialhealthjournal.com/PDF/bshj-1-146.pdf
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author Azita Emami
Jeehye Jun
Gabriella Engström
Lars Berglund
Töres Theorell
author_facet Azita Emami
Jeehye Jun
Gabriella Engström
Lars Berglund
Töres Theorell
author_sort Azita Emami
collection DOAJ
description Introduction: Accurate estimates of intra-individual variability are necessary for proper design of clinical trials and epidemiological studies where the stress biomarkers cortisol and dehydroepiandrosterone sulfate (DHEA-S) are measured for dyads of persons with dementia (PWDs) and their family caregivers (FCGs). The aim is to determine the number of consecutive sampling days required to detect effect differences in clinical trials, and to accurately estimate regression coefficients in epidemiological studies where stress biomarkers are exposure variables in regression models with future disease as outcome. Methods: Clinical trial data from dyads of PWDs and their FCGs were used. Salivary cortisol and DHEA-S samples were collected five days a week, for eight consecutive weeks. From this data, we created formulas and graphical tools for the number of required sampling days needed to detect effect differences, and we calculated number of days needed for regression coefficients to be estimated with<10% bias. Results: A total of 5791 salivary samples from 34 dyads were used. For morning cortisol, five consecutive sampling days at baseline and an equal number of days at study termination is sufficient to detect a treatment difference>5% of baseline level with>20 dyads per group. When stress biomarkers are used in epidemiological studies at least six consecutive sampling days are required. Conclusion: Based on a large number of consecutive measurements of stress biomarkers we calculated the sufficient numbers of sampling days for clinical trials and for epidemiological studies to produce credible results. Our findings will aid researchers in the study design phase.
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spelling doaj-art-f1f170589cdc45c9bf4afc6ef4f85d3d2025-02-06T10:34:49ZengTabriz: Hamid Allahverdipour, 2024-BioSocial Health Journal3060-62682024-11-011314615310.34172/bshj.29bshj-29Sample size calculations based on day-to-day variability of stress biomarkers in persons with dementia and their family caregiversAzita Emami0Jeehye Jun1Gabriella Engström2Lars Berglund3Töres Theorell4Yale School of Nursing, Yale University, PO Box 27399, West Haven, CT, 06516 USARed Cross College of Nursing, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul, Republic of KoreaFlorida Atlantic University, Charles E. Schmidt College of Medicine, 777 Glades Road, Boca Raton, Florida, 33431 USADepartment of Public Health and Caring Sciences, Geriatrics, Uppsala University, Box 564, 751 22 Uppsala, SwedenStress Research Institute, Department of Psychology, Stockholm University, Frescativägen 8, 106 91 Stockholm, SwedenIntroduction: Accurate estimates of intra-individual variability are necessary for proper design of clinical trials and epidemiological studies where the stress biomarkers cortisol and dehydroepiandrosterone sulfate (DHEA-S) are measured for dyads of persons with dementia (PWDs) and their family caregivers (FCGs). The aim is to determine the number of consecutive sampling days required to detect effect differences in clinical trials, and to accurately estimate regression coefficients in epidemiological studies where stress biomarkers are exposure variables in regression models with future disease as outcome. Methods: Clinical trial data from dyads of PWDs and their FCGs were used. Salivary cortisol and DHEA-S samples were collected five days a week, for eight consecutive weeks. From this data, we created formulas and graphical tools for the number of required sampling days needed to detect effect differences, and we calculated number of days needed for regression coefficients to be estimated with<10% bias. Results: A total of 5791 salivary samples from 34 dyads were used. For morning cortisol, five consecutive sampling days at baseline and an equal number of days at study termination is sufficient to detect a treatment difference>5% of baseline level with>20 dyads per group. When stress biomarkers are used in epidemiological studies at least six consecutive sampling days are required. Conclusion: Based on a large number of consecutive measurements of stress biomarkers we calculated the sufficient numbers of sampling days for clinical trials and for epidemiological studies to produce credible results. Our findings will aid researchers in the study design phase.https://biosocialhealthjournal.com/PDF/bshj-1-146.pdfbiomarkerscaregiversclinical trialhydrocortisonedementiadehydroepiandrosterone sulfateepidemiologic studiessample size
spellingShingle Azita Emami
Jeehye Jun
Gabriella Engström
Lars Berglund
Töres Theorell
Sample size calculations based on day-to-day variability of stress biomarkers in persons with dementia and their family caregivers
BioSocial Health Journal
biomarkers
caregivers
clinical trial
hydrocortisone
dementia
dehydroepiandrosterone sulfate
epidemiologic studies
sample size
title Sample size calculations based on day-to-day variability of stress biomarkers in persons with dementia and their family caregivers
title_full Sample size calculations based on day-to-day variability of stress biomarkers in persons with dementia and their family caregivers
title_fullStr Sample size calculations based on day-to-day variability of stress biomarkers in persons with dementia and their family caregivers
title_full_unstemmed Sample size calculations based on day-to-day variability of stress biomarkers in persons with dementia and their family caregivers
title_short Sample size calculations based on day-to-day variability of stress biomarkers in persons with dementia and their family caregivers
title_sort sample size calculations based on day to day variability of stress biomarkers in persons with dementia and their family caregivers
topic biomarkers
caregivers
clinical trial
hydrocortisone
dementia
dehydroepiandrosterone sulfate
epidemiologic studies
sample size
url https://biosocialhealthjournal.com/PDF/bshj-1-146.pdf
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