Assessing Adherence, Competence and Differentiation in a Stepped-Wedge Randomised Clinical Trial of a Complex Behaviour Change Intervention

Abstract

Background: A key challenge in behavioural medicine is developing interventions that can be delivered adequately (i.e., with fidelity) within real-world consultations. Accordingly, clinical trials should (but tend not to) report what is actually delivered (adherence), how well (competence) and the distinction between intervention and comparator conditions (differentiation). Purpose: To address this important clinical and research priority, we apply best practice guidelines to evaluate fidelity within a real-world, stepped-wedge evaluation of “EAT: Eating As Treatment”, a new dietitian delivered health behaviour change intervention designed to reduce malnutrition in head and neck cancer (HNC) patients undergoing radiotherapy. Methods: Dietitians (n = 18) from five Australian hospitals delivered a period of routine care and following a randomly determined order each site received training and began delivering the EAT Intervention. A 20% random stratified sample of audio-recorded consultations (control n = 196; intervention n = 194) was coded by trained, independent, raters using a study specific checklist and the Behaviour Change Counselling Inventory. Intervention adherence and competence were examined relative to apriori benchmarks. Differentiation was examined by comparing control and intervention sessions (adherence, competence, non-specific factors, and dose), via multiple linear regression, logistic regression, or mixed-models. Results: Achievement of adherence benchmarks varied. The majority of sessions attained competence. Post-training consultations were clearly distinct from routine care regarding motivational and behavioural, but not generic, skills. Conclusions: Although what level of fidelity is “good enough” remains an important research question, findings support the real-world feasibility of integrating EAT into dietetic consultations with HNC patients and provide a foundation for interpreting treatment effects.

Is fidelity to a complex behaviour change intervention associated with patient outcomes? Exploring the relationship between dietitian adherence and competence and the nutritional status of intervention patients in a successful stepped-wedge randomised clinical trial of eating as treatment (EAT)

“…Our findings demonstrated that the primary outcome of nutritional status (as measured by the Patient-Generated Subjective Global Assessment; PGSGA [36]) was superior for intervention relative to control participants (β = −1.53; confidence interval = −2.93 to −0.13 [34]). Furthermore, fidelity analysis [32] confirmed that (a) objective ratings of dietitian adherence and competence favoured intervention relative to control sessions [32], and (b) intervention sessions were clearly distinct regarding core motivational and behavioural intervention elements, whereas generic or 'common' intervention elements remained stable [32]. In light of this evidence for both intervention effects and intervention fidelity, we now take the next step [26] in the evaluation of the EAT intervention and conduct a process analysis.…”

“…This research was conducted in accordance with the National Statement on Ethical conduct in Human Research [37]. Further information regarding study methods and findings are available in published protocol and outcome papers from the fidelity evaluation [32,33] and overarching clinical trial [34,35].…”

“…Fidelity assessment in the EAT clinical trial was conducted using a randomly selected 20% sample of audiorecorded dietetic consultations conducted before (n= 196) and after (n=194) training in EAT [32,33]. In the current paper, we focus on the dietitian adherence and competence outcomes derived from the 194 randomly selected sessions conducted during the intervention phase of the EAT clinical trial.…”

“…Practitioner discusses the adequacy of the patient's energy intake Practitioner conducts a formal/standardised assessment to measure patient nutrition Practitioner discusses how eating/nutrition is an integral part of "radiotherapy" treatment** Practitioner encourages the patient to discuss their reason(s) for undergoing radiotherapy** Practitioner collaboratively develops a formal, written nutrition plan with the patient** Practitioner encourages the patient to discuss their progress towards the goals outlined on their written nutrition plan **Adherence to these items was found to be significantly greater during intervention relative to control sessions (p<.001) [32] delivered within the required 'spirit' (i.e. a high degree of empathy, warmth, genuineness and concern).…”

“…Greater attention to fidelity [1,9], including the conduct of process analyses [26], is central to improving understanding of the relationship between fidelity and intervention effects. Accordingly, we recently applied published recommendations [2][3][4] to the design and conduct of a comprehensive fidelity evaluation [32,33] within a real-world multi-site stepped-wedge randomised controlled trial of 'EAT: Eating as Treatment'. EAT is a complex health behaviour change intervention designed to reduce malnutrition in head and neck cancer (HNC) patients undergoing radiotherapy [34,35].…”