Systematic review of ethics committee approval and participant information and consent in reports of cluster randomized trials – discrepancies between author answers and reporting.

Data are number (%).aPercentages represent the proportion of published reports stating the piece of information given by corresponding authors.bAn ethics committee approval was considered obtained any time the corresponding author specified having difficulties or not in obtaining its approval.cSubset of trials for which authors answered that participants had been informed, and included after clusters had been randomized.dSubset of trials for which we considered active recruitment took place.