Multidimensional fidelity of the EPIC-Neck exercise programme for chronic non-specific neck pain: a UK feasibility trial process evaluation.

OBJECTIVES

To evaluate multidimensional fidelity of the EPIC-Neck programme (Exercise Prescription Improved through Co-design).

DESIGN

Mixed-methods fidelity evaluation embedded within a randomised controlled feasibility study.

SETTING

UK National Health Service (NHS) musculoskeletal outpatient services.

PARTICIPANTS

Physiotherapists delivering and adults with chronic non-specific neck pain receiving the EPIC-Neck programme.

INTERVENTION: EPIC-Neck is an individualised, evidence- and theory-informed exercise programme combining optimised exercise prescription and behaviour change techniques to support four performance objectives (POs): perform prescribed exercise (PO1), progress/regress exercise (PO2), use exercise to manage flare-ups (PO3) and engage in general exercise (PO4).

FIDELITY EVALUATION: Fidelity was evaluated in four domains: training, delivery, receipt and enactment. Quantitative data were questionnaires on physiotherapist confidence pretraining/post-training (1–5 Likert scale) and training satisfaction (training), a 17-item delivery fidelity checklist applied to audio-recorded appointments (0–5; 3=acceptable) (delivery) and patient-reported confidence for undertaking POs 1–3 (receipt). Quantitative data were analysed descriptively. Qualitative data were physiotherapists’ interviews on training and delivery and patient interviews on PO understanding, confidence and completion (receipt, enactment). Interviews underwent inductive-deductive thematic analysis. Quantitative and qualitative data were integrated through narrative weaving for training/receipt and connected sequentially for delivery.

RESULTS

24 participants were randomised to EPIC-Neck; 22 contributed quantitative delivery data, 18 contributed quantitative receipt data, and 12 were interviewed. Seven physiotherapists delivered EPIC-Neck, and five were interviewed. Physiotherapist confidence improved after training (median 3/5 to 4/5), but qualitative data indicated they remained underprepared. Mean delivery fidelity was below the acceptable threshold (2.4/5, SD 1.3), with the poorest delivery for social support, problem-solving and PO2–PO4 (<2/5). Participants generally understood and enacted prescribed neck exercises, but receipt and enactment were weaker for complex/resisted exercises and longer-term self-management behaviours (PO2–PO4).

CONCLUSION

Although training improved confidence, it did not fully prepare physiotherapists for the delivery of more complex components. Overall delivery fidelity was below the acceptable threshold, indicating that EPIC-Neck was not consistently delivered as intended. Receipt and enactment were stronger for performing neck exercises than for longer-term self-care behaviours. Intervention and training refinement are required before a definitive trial.

TRIAL REGISTRATION NUMBER: ISRCTN81746901.