Optimising physiotherapist delivery fidelity of exercise and physical activity advice for achilles tendinopathy: A prospective repeated-measures observational study

Objectives: To assess physiotherapist delivery fidelity and identify factors optimising delivery fidelity of an intervention based on recommended guidelines for Achilles tendinopathy. Design: A prospective repeated-measures observational study of physiotherapist delivery fidelity with carefully defined exercise and physical activity advice. Setting: An inter-disciplinary clinic in Melbourne, Australia, embedded in a randomised controlled trial. Participants: Two physiotherapists delivering the intervention to five participants each, at three timepoints. Intervention: All participants were expected to receive the same intervention. Feedback at timepoint one, guided boost-training to optimise delivery fidelity. Main outcome measures: Proportion of exercise and physical activity advice components delivered as intended (high ≥80%; moderate 51–79%; low≤50%), with relationships between variables analysed using chi-square tests. Results: Physiotherapist delivery fidelity improved significantly between timepoint one and two (χ² = 83.3, p < 0.001), then sustained at timepoint three. At timepoint one, seven (70%) of intervention components were delivered with high fidelity, one (10%) with moderate fidelity and two (20%) with low fidelity. At timepoint two, after boost-training, nine (90%) were delivered with high fidelity and one (10%) with moderate fidelity. At timepoint three, all intervention components (100%) were delivered with high fidelity by both physiotherapists. Conclusion: Physiotherapist delivery fidelity can be optimised with feedback, collaboration and boost-training.