To use the Theoretical Domains Framework (TDF) to identify barriers and enablers to participant retention in trials requiring questionnaire return and/or attendance at follow-up clinics.
 
  We invited participants (n=607) from five pragmatic effectiveness trials, who missed at least one follow-up time point (by not returning a questionnaire and/or not attending a clinic visit), to take part in semistructured telephone interviews. The TDF informed both data collection and analysis. To establish what barriers and enablers most likely influence the target behavior the domain relevance threshold was set at >75% of participants mentioning the domain.
 
  Sixteen participants (out of 25 showing interest) were interviewed. Overall, seven theoretical domains were identified as both barriers and enablers to the target behaviors of attending clinic appointments and returning postal questionnaires. Barriers frequently reported in relation to both target behaviours stemmed from participants' knowledge, beliefs about their capabilities and the consequences of performing (or not performing) the behavior. Two domains were identified as salient for questionnaire return only goals; and memory, attention and decision-making. Emotion was identified as relevant for clinic attendance only.
 
  This is the first study informed by behavioural science to explore trial participants' accounts of trial retention.  https://www.selleckchem.com/products/FK-506-(Tacrolimus).html  Findings will serve as a guiding framework when designing trials to limit barriers and enhance enablers of retention within clinical trials.
 This is the first study informed by behavioural science to explore trial participants' accounts of trial retention. Findings will serve as a guiding framework when designing trials to limit barriers and enhance enablers of retention within clinical trials.
  Participants in intervention studies are asked to take part in activities linked to the conduct of research, including signing consent forms and being assessed. If participants are affected by such activities through mechanisms by which the intervention is intended to work, then there is confounding. We examine how to account for research participation effects analytically.
 
  Data from a trial of a brief alcohol intervention among Swedish university students is used to show how a proposed causal model can account for assessment effects.
 
  The proposed model can account for research participation effects as long as researchers are willing to use existing data to make assumptions about causal influences, for instance on the magnitude of assessment effects. The model can incorporate several research processes which may introduce bias.
 
  As our knowledge grows about research participation effects, we may move away from asking if participants are affected by study design, toward rather asking by how much they are affected, by which activities and in which circumstances. The analytic perspective adopted here avoids assuming there are no research participation effects.
 As our knowledge grows about research participation effects, we may move away from asking if participants are affected by study design, toward rather asking by how much they are affected, by which activities and in which circumstances. The analytic perspective adopted here avoids assuming there are no research participation effects.
  Oral lichen planus (OLP) is a common oral inflammatory condition. Against symptomatic atrophic-erosive OLP, topical steroids, or photobiomodulation (PBM) are deployed. Optical coherence tomography (OCT) provides a real-time, non-invasive, tissue investigation. Aim of this study was to evaluate modifications of OCT pattern in patients with painful atrophic-erosive OLP, before and after treatment with PBM, comparing those results with patients treated with topical steroid.
 
  Two groups of 20 OLP patients were evaluated. Group A underwent two daily application of 0.05 % clobetasol propionate for 8 weeks; group B was treated with eight weekly PBM sessions using a 980/645 nm diode laser. OCT scans were performed before and after treatment, and six months after end of the proposed protocol. Changes of width of stratified epithelium (EP) and lamina propria (LP) were quantified.
 
  After 8-weeks, both groups experienced a significant increase of EP width (p < 0.05), and a significant decrease of LP width (p < 0.05), with Δ-EP in Group A significantly higher than Group B (p = 0.0015); conversely, Δ-LP was not significantly different (p > 0.05). After six months, significant increase of EP width remained only in group B (p = 0.01), with no significant decrease of LP mean width in both groups (p > 0.05).
 
  Increase of EP and decrease of LP might be explained as consequence of clobetasol and PBM ability to promote epithelial healing, and to reduce interface inflammation. When investigated with OCT, clobetasol appears to provide more significant short-term structural changes, whereas PBM might guarantee long-term alterations.
 Increase of EP and decrease of LP might be explained as consequence of clobetasol and PBM ability to promote epithelial healing, and to reduce interface inflammation. When investigated with OCT, clobetasol appears to provide more significant short-term structural changes, whereas PBM might guarantee long-term alterations.Panic disorder (PD) is a harmful mental condition that causes relapsed and persistent impairment. In the treatment of PD, the prognosis for PD should be considered. However, the relationship between pharmacotherapy and biomarkers, for predicting a better response through neuroimaging, is a little known. The purpose of the present study was to examine whether there would be the initial white matter (WM) regions associated with the remission in 6 months. A total of 104 patients with PD were investigated in the study. After six months, there were 17 remission patients with PD and 81 non-remission patients. The Panic Disorder Severity Scale, Albany Panic and Phobia Questionnaire, Anxiety Sensitivity Inventory-Revised, Beck Anxiety Inventory, and Beck Depression Inventory were assessed for all patients at baseline. We compared the diffusion indices between remission and non-remission group at 6 months using Tract-Based Spatial Statistics. The results showed that the fractional anisotropy (FA) values were significantly higher in the non-remitter group compared with those in the remitter group in the WM regions, such as the posterior corona radiata and superior longitudinal fasciculus, at the 6 month evaluation.