Caution Regarding the Use of Pilot Studies to Guide Power Calculations for Study Proposals

Kraemer, Helena C.; Mintz, Jim; Noda, Art; Tinklenberg, Jared R.; Yesavage, Jerome A.

doi:10.1001/archpsyc.63.5.484

Cited by 597 publications

(497 citation statements)

References 25 publications

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“…Teaching caregivers activity use has added value by reducing their objective burden and enhancing skills. Given that pilot studies tend to yield large effect sizes (42), and that the control group did not evince benefit in all areas as the experimental group after treatment receipt, it is important to test TAP on a larger scale, validate it with diverse dyads, and examine the underlying physiological mechanisms by which symptom reduction occurs.…”

Section: Discussionmentioning

confidence: 99%

Tailored Activities to Manage Neuropsychiatric Behaviors in Persons With Dementia and Reduce Caregiver Burden: A Randomized Pilot Study

Gitlin

Winter

Burke

et al. 2008

American Journal of Geriatric Psychiatry

144

216

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Objective-To test whether the Tailored Activity Program for at-home dementia patients reduces neuropsychiatric behaviors and caregiver burden.Method-A prospective, two-group controlled pilot study with 60 dyads randomized to treatment or wait-list control. Dyads were interviewed at baseline and 4 months (trial endpoint); control participants then received intervention and were reassessed 4 months later. The 8-session occupational therapy intervention involved neuropsychological and functional testing from which activities were customized and instruction in use provided to caregivers. Conclusions-Results suggest clinically-relevant benefits for both dementia patients and caregivers, with treatment minimizing the occurrence of behaviors that commonly trigger nursing home placement. (1) Neuropsychiatric behaviors such as apathy, depressed affect, lability, agitation, and aggressiveness are common occurrences, with most patients manifesting these behaviors over the course of the disease. (2,3,4) Behaviors are the most challenging aspect of caregiving, contributing to caregiver distress, depression, increased care costs, and risk for nursing home placement. (5,6,7,8) There are few tested interventions to minimize behavioral occurrences. Recent research has shown that pharmacological approaches may not be effective and may cause harm (9,10,11). A few caregiver intervention studies report minimal behavioral benefits (12,13,14,15), with most studies not examining patient symptom reduction. Thus, developing and testing nonpharmacological approaches to address behaviors is an important public health priority as articulated in recent position statements by the American Association for Geriatric Psychiatry (16) and Annals of Internal Medicine. (17) One promising approach is activity. Research shows that purposeful activity results in reduced depressive and agitated behaviors. (18,19) However, studies have focused exclusively on nursing home residents, involved small sample sizes, used non-experimental designs, or have not tested systematic approaches to developing activities. Lack of research on communityliving patients is significant given that the home is the primary care setting for this population. Results-At KeywordsThis pilot controlled study evaluates an activity-based intervention, the Tailored Activity Program (TAP) that seeks to reduce behavioral disturbances by identifying patients' preserved capabilities and devising activities that build on them. The trial tested whether tailored activities reduced behavioral occurrences in dementia patients and caregiver burden and enhanced patient engagement, caregiver mastery, self-efficacy, and use of simplification strategies to manage behaviors. Also, because the intervention required caregiver involvement, we evaluated whether caregiver depressive symptoms moderated dementia patient and caregiver outcomes.Using a two-group randomized, parallel design, 60 dyads (dementia patients and their caregivers) were assigned to treatment or wait-list control. Treatment grou...

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Section: Discussionmentioning

confidence: 99%

Tailored Activities to Manage Neuropsychiatric Behaviors in Persons With Dementia and Reduce Caregiver Burden: A Randomized Pilot Study

Gitlin

Winter

Burke

et al. 2008

American Journal of Geriatric Psychiatry

144

216

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Section: Discussionmentioning

confidence: 99%

“…We are less certain about the correlational analyses. We did not perform a pilot study before this project (for cautionary notes regarding the use of pilot studies for power calculations, see Kraemer, Mintz, Noda, Tinklenberg, & Yesavage, 2006), and thus the analyses need to be regarded as exploratory.In conclusion, depressed and nondepressed participants at risk for CVD differ in PA and NA but not in cortisol or cardiopulmonary variables measured at several times during the day.Furthermore, the same sample demonstrated an impaired cortisol response to psychological stress, and a lower TF-RSA, although their cardiovascular reactivity was otherwise similar to controls . HRV was related to NA in controls but not among depressed patients with CVD risk.…”

mentioning

confidence: 99%

Circadian affective, cardiopulmonary, and cortisol variability in depressed and nondepressed individuals at risk for cardiovascular disease

Conrad

Wilhelm

Roth

et al. 2008

Journal of Psychiatric Research

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Depression is a risk factor for cardiovascular disease (CVD) perhaps mediated by hypothalamicpituitary-adrenal (HPA) axis or vagal dysregulation. We investigated circadian mood variation and HPA-axis and autonomic function in older (≥55 years) depressed and nondepressed volunteers at risk for CVD by assessing diurnal positive and negative affect (PA, NA), cortisol, and cardiopulmonary variables in 46 moderately depressed and 19 nondepressed volunteers with elevated CVD risk. Participants sat quietly for 5-min periods (10:00, 12:00, 14:00, 17:00, 19:00, 21:00), and then completed an electronic diary assessing PA and NA. Traditional and respiration-controlled heart rate variability (HRV) variables were computed for these periods as an index of vagal activity. Salivary cortisols were collected at waking, waking+30 min, 12:00, 17:00, and 21:00 hours. Cortisol peaked in the early morning after waking, and gradually declined over the day, but did not differ between groups. PA was lower and NA was higher in the depressed group throughout the day. HRV did not differ between groups. Negative emotions were inversely related to respiratory sinus arrhythmia in nondepressed participants. We conclude that moderately depressed patients do not show abnormal HPA-axis function. Diurnal PA and NA distinguish depressed from nondepressed patients at risk for CVD, while measures of vagal regulation, even when controlled for physical activity and respiratory confounds, do not. Diurnal mood variations of older individuals at risk for CVD differ from those reported for other groups and daily fluctuations in NA are not related to cardiac autonomic control in depressed individuals. KeywordsCardiovascular Disease; Cortisol; Depression; Heart Rate Variability Depression has a major impact on mortality, morbidity, and functional recovery in patients with cardiovascular disease (CVD) (Carney, Freedland, & Sheps, 2004). Several mechanisms have been proposed to explain how depression might increase CVD risk, including Corresponding Author: Frank H. Wilhelm, Ph.D.; Tel.: ++41-61-267 0593; Fax: ++41-61-267 0659; E-mail: frank.wilhelm@unibas.ch; Address: Institute for Psychology, University of Basel, Missionsstrasse 60/62, CH-4055 Basel, Switzerland. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. (Musselman, Evans, & Nemeroff, 1998). Abnormal HPA-axis function may contribute to CVD risk through a variety of related risk factors, including hypertension, high lipids, insulin resistance, and abdominal obesity, together constituting the metabolic syndrome (Brown, Varghese, & McEwen, 2004). Several stu...

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“…Controversies around the applicability of randomization stem from situations where preliminary data suggests a new treatment being significantly more effective than the standard treatment [65]. However, preliminary data from smaller preceding clinical trials rarely provide reliable effect size estimates [66], and therefore cannot give sufficient evidence against clinical equipoise. Following the experiences with the early clinical trials during the HIV/AIDS pandemic in the 1980s, a controversy erupted over whether in the absence of a standard treatment all patients should receive immediate access to study treatment, with only a remote chance of improvement.…”

Section: Common Challenges Randomization Controls and Equipoisementioning

confidence: 99%

Clinical Trials in Neurovirology: Successes, Challenges, and Pitfalls

Haubenberger

Clifford

2016

Neurotherapeutics

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Clinical trials in neurovirology illustrate the special challenges confronting investigators planning to study these conditions, as well as the contributions of successful trials in establishing appropriate management for these devastating diseases. This article reviews key examples of progress in neurovirology that have been spurred by clinical trials, emphasizing human herpes virus encephalitis, HIV, and JC virus. Clinical trials in the setting of neurovirological diseases are characterized by specific challenges, which may include small sample sizes, clinical presentations from life-threatening conditions to chronic courses of disease, regional and temporally restricted outbreaks scenarios, and the unavailability of validated diagnostic tests that can be rapidly deployed at the bedside. This review aims to highlight these methodological challenges and pitfalls in designing and executing clinical neurovirology trials, as well as to outline innovative trial designs, which could be useful in addressing common challenges.

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Caution Regarding the Use of Pilot Studies to Guide Power Calculations for Study Proposals

Cited by 597 publications

References 25 publications

Tailored Activities to Manage Neuropsychiatric Behaviors in Persons With Dementia and Reduce Caregiver Burden: A Randomized Pilot Study

Tailored Activities to Manage Neuropsychiatric Behaviors in Persons With Dementia and Reduce Caregiver Burden: A Randomized Pilot Study

Circadian affective, cardiopulmonary, and cortisol variability in depressed and nondepressed individuals at risk for cardiovascular disease

Clinical Trials in Neurovirology: Successes, Challenges, and Pitfalls

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