Comparison of registered and published intervention fidelity assessment in cluster randomised trials of public health interventions in low- and middle-income countries: systematic review protocol.

Cluster randomised trials (CRTs) are a key instrument to evaluate public health interventions, particularly in low- and middle-income countries (LMICs). Fidelity assessment examines study processes to gauge whether an intervention was delivered as initially planned. Evaluation of implementation fidelity (IF) is required to establish whether the measured effects of a trial are due to the intervention itself and may be particularly important for CRTs of complex interventions. Current CRT reporting guidelines offer no guidance on IF assessment. We will systematically review the scientific literature to study current practices concerning the assessment of IF in CRTs of public health interventions in LMICs.