2013 ◽  
Vol 55 (4) ◽  
pp. 617-633 ◽  
Author(s):  
Simon Schneider ◽  
Heinz Schmidli ◽  
Tim Friede

2009 ◽  
Vol 42 (2) ◽  
pp. 262-271
Author(s):  
Suzhen Wang ◽  
Jielai Xia ◽  
Lili Yu ◽  
Chanjuan Li ◽  
Li Xu ◽  
...  

2017 ◽  
Author(s):  
Angela M Rodrigues ◽  
Falko F Sniehotta ◽  
Mark A Birch-Machin ◽  
Patrick Olivier ◽  
Vera Ara�jo-Soares

BACKGROUND Recreational sun exposure has been associated with melanoma prevalence, and tourism settings are of particular interest for skin cancer prevention. Effective, affordable, and geographically flexible interventions to promote sun protection are needed. OBJECTIVE The aim of this study was to describe the protocol for a definitive randomized controlled trial (RCT) evaluating a smartphone mobile intervention (mISkin app) promoting sun protection in holidaymakers and to assess the acceptability and feasibility of the mISkin app and associated trial procedures in an internal pilot study. METHODS Participants were recruited from the general community. Holidaymakers traveling abroad and owning a smartphone were enrolled in the internal pilot of a 2 (mISkin vs control) x 2 (sun protection factor [SPF] 15 vs SPF 30) RCT with a postholiday follow-up. The smartphone app is fully automated and entails a behavioral intervention to promote sun protection. It consisted of five components: skin assessment, educational videos, ultraviolet (UV) photos, gamification, and prompts for sun protection. Participants were also randomly allocated to receive sunscreen SPF 15 or SPF 30. Primary outcomes for the internal pilot study were acceptability and feasibility of trial procedures and intervention features. Secondary outcomes were collected at baseline and after holidays through face-to-face-assessments and included skin sun damage, sunscreen use (residual weight and application events), and sun protection practices (Web-based questionnaire). RESULTS From 142 registers of interest, 42 participants were randomized (76% [32/42] female; mean age 35.5 years). Outcome assessments were completed by all participants. Random allocation to SPF 15 versus SPF 30 was found not to be feasible in a definitive trial protocol. Of the 21 people allocated to the mISkin intervention, 19 (91%) installed the mISkin on their phones, and 18 (86%) used it at least once. Participants were satisfied with the mISkin app and made suggestions for further improvements. Due to difficulties with the random allocation to SPF and slow uptake, the trial was discontinued. CONCLUSIONS The internal pilot study concluded that randomization to SPF was not feasible and that recruitment rate was slower than expected because of difficulties with gatekeeper engagement. Possible solutions to the problems identified are discussed. Further refinements to the mISkin app are needed before a definitive trial. CLINICALTRIAL International Standard Randomized Controlled Trial Number ISRCTN63943558; http://www.isrctn.com/ISRCTN63943558 (Archived by WebCite at http://www.webcitation.org/6xOLvbab8)


2018 ◽  
Vol 28 (6) ◽  
pp. 1852-1878
Author(s):  
Maria M Ciarleglio ◽  
Christopher D Arendt

When designing studies involving a continuous endpoint, the hypothesized difference in means ([Formula: see text]) and the assumed variability of the endpoint ([Formula: see text]) play an important role in sample size and power calculations. Traditional methods of sample size re-estimation often update one or both of these parameters using statistics observed from an internal pilot study. However, the uncertainty in these estimates is rarely addressed. We propose a hybrid classical and Bayesian method to formally integrate prior beliefs about the study parameters and the results observed from an internal pilot study into the sample size re-estimation of a two-stage study design. The proposed method is based on a measure of power called conditional expected power (CEP), which averages the traditional power curve using the prior distributions of θ and [Formula: see text] as the averaging weight, conditional on the presence of a positive treatment effect. The proposed sample size re-estimation procedure finds the second stage per-group sample size necessary to achieve the desired level of conditional expected interim power, an updated CEP calculation that conditions on the observed first-stage results. The CEP re-estimation method retains the assumption that the parameters are not known with certainty at an interim point in the trial. Notional scenarios are evaluated to compare the behavior of the proposed method of sample size re-estimation to three traditional methods.


2021 ◽  
pp. 1-10
Author(s):  
Guida da Ponte ◽  
Sílvia Ouakinin ◽  
Jorge Espírito Santo ◽  
Afolabi Ohunakin ◽  
Domingos Prata ◽  
...  

Abstract Objective To describe the feasibility of a meaning-centered group psychotherapy (MCGP) adaptation in a sample of Portuguese cancer patients. Method The study was carried out according to four steps: 1st — Transcultural adaptation and validation (focus groups); 2nd — Preliminary study with MCGP original version (to test its feasibility); 3rd — Adaptation of MCGP original version to a 4-session version (and internal pilot study); and 4th — Pilot exploratory trial (MCGP-4 session version), implemented between January 1, 2018 and December 31, 2019. Inclusion criteria were >18 years, psychological complaints, and difficulty to adapt to cancer. Allocation was according to participants’ preference: MCGP vs. care as usual (CAU). Primary outcomes were: MCGP adapted version improved quality of life (QoL) and spiritual well-being; secondary outcomes were improvement of depression, anxiety, and distress. Assessments were done at baseline (T1) and 1 month after (T2), with self-report socio-demographic and clinical questionnaires, Distress Thermometer (DT), McGill Quality of Life Questionnaire (MQOL), Functional Assessment of Chronic Illness Therapy — Spiritual Well-Being Scale (FACIT-Sp-12), Hospital Anxiety and Depression Scale, and its subscales (HADS — HADS-D, HADS-A). Results In the 1st step, and through focus groups, the manual was reformulated and tested. The preliminary study (2nd step) with MCGP original version showed a high number of dropouts which could jeopardize the study and, after reframing the sessions content, MCGP was adapted to a 4-session version, and its feasibility was tested by an internal pilot study (3rd step). The pilot exploratory trial (4th step) had 91 participants. Most socio-demographic and clinical characteristics between the groups (51: MCGP; 40: CAU) had no statistically significant differences. A comparison between the two groups at T2 showed that the MCGP group scored significantly higher in the general (U = 552.00, P < 0.001), and existential (U = 727.50, P = 0.018) domains and total score (U = 717.50, P = 0.015) of QoL, and CAU presented statistical higher levels in DT (U = 608.50, P = 0.001). Comparing the groups between T1 and T2, the MCGP group had a statistically significant improvement in the general (Z = −3.67, P < 0.001) and psychosocial (Z = −2.89, P = 0.004) domains and total score (Z = −2.71, P = 0.007) of QoL, and a statistically significant decrease in DT (Z = −2.40, P = 0.016). In terms of group effects, the MCGP group presented increased general (b = 1.42, P < 0.001, η2p = 0.179), and support (b = 0.80, P = 0.045, η2p = 0.048) domains and total score (b = 0.81, P = 0.013, η2p = 0.073) of QoL (small to elevated dimensions), and decreased levels of depression (b = −1.14, P = 0.044, η2p = 0.048), and distress (b = −1.38, P = 0.001, η2p = 0.127) (small to medium dimensions), compared with CAU. At T2, participants who attended ≥3 sessions (n = 38) had a statistically significant higher score in the general domain (U = 130.50, P = 0.009) of QoL, comparing with those who attended 1 or 2 sessions (n = 13). Significance of results This study supports the benefits of an MCGP adapted version in improving QoL and psychologic well-being. More studies are necessary to address the limitations of this pilot exploratory trial, as its small sample size.


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