How and why a multifaceted intervention to improve adherence post-MI worked for some (and could work better for others): an outcome-driven qualitative process evaluation

Objectives To explore (1) the extent to which a multicomponent intervention addressed determinants of the desired behaviours (ie, adherence to cardiac rehabilitation (CR) and cardiovascular medications), (2) the associated mechanism(s) of action and (3) how future interventions might be better designed to meet the needs of this patient population.Design A qualitative evaluation embedded within a multicentre randomised trial, involving purposive semistructured interviews.Setting Nine cardiac centres in Ontario, Canada.Participants Potential participants were stratified according to the trial’s primary outcomes of engagement and adherence, resulting in three groups: (1) engaged, adherence outcome positive, (2) engaged, adherence outcome negative and (3) did not engage, adherence outcome negative. Participants who did not engage but had positive adherence outcomes were excluded. Individual domains of the Theoretical Domains Framework were applied as deductive codes and findings were analysed using a framework approach.Results Thirty-one participants were interviewed. Participants who were engaged with positive adherence outcomes attributed their success to the intervention’s ability to activate determinants including behavioural regulation and knowledge, which encouraged an increase in self-monitoring behaviour and awareness of available supports, as well as reinforcement and social influences. The behaviour of those with negative adherence outcomes was driven by beliefs about consequences, emotions and identity. As currently designed, the intervention failed to target these determinants for this subset of participants, resulting in partial engagement and poor adherence outcomes.Conclusion The intervention facilitated CR adherence through reinforcement, behavioural regulation, the provision of knowledge and social influence. To reach a broader and more diverse population, future iterations of the intervention should target aberrant beliefs about consequences, memory and decision-making and emotion.Trial registration number ClinicalTrials.gov registry; NCT0238273

Progression and variability of TNBS colitis-associated inflammation in rats assessed by contrast-enhanced and T2-weighted MRI

BACKGROUND: A common feature of preclinical models of colitis is that the time-course, magnitude, and persistence of inflammation vary considerably within the experimental animal group. Accordingly, noninvasive, serial quantification of colonic inflammation could advantageously guide dosing regimens and assess drug efficacy, thus enhancing the value of colitis models in research. This investigation using magnetic resonance imaging (MRI) was therefore undertaken to objectively determine inflammatory progression, variability, and response to therapy associated with trinitrobenzene sulfonic acid (TNBS)-induced colitis in Wistar rats. METHODS: Rats underwent TNBS treatment on Day 0 and received sulfasalazine or vehicle (methylcellulose) orally, daily, from Day -1 (prophylactically) or Day 2 (therapeutically). T2-weighted and semidynamic T1-weighted contrast-enhanced MRI (CE-MRI) was repeated over 7-10 days to measure colon wall thickness and perfusion-related aspects of inflammation. Rectal bleeding, stool consistency, and disease activity were scored throughout and colon pathology determined terminally. RESULTS: Principal component analysis of the CE-MRI time-series highlighted colon wall and mesenteric inflammation, which increased by 6-8x naïve values. Peristaltic artifacts were distinguished from perfusion changes using the normalized temporal standard deviation. MRI correlated strongly with terminal colon weight (mean correlation r = 0.8), well with body weight change (r = -0.7), but little with conventional clinical scores. Sulfasalazine reduced inflammation administered prophylactically and therapeutically. CONCLUSIONS: Inflammation and therapeutic efficacy can be sensitively quantified noninvasively using MRI in TNBS-treated rats. This methodology provides unique and objective in vivo measures of inflammation that can guide dosing strategies, enhancing colitis research effectiveness and the assessment of potential IBD therapeutics