Sample and Recruitment
RECRUITMENT
Eligible participants for randomization were women aged 18 or more, classified as Robson 1 (Participant recruitment was carried out by the midwives and assistant nurses at the labor ward. Eligible women were asked to participate after labor ward arrival and confirmed active stage of labor, if both a regular room and the new room were vacant. All women gave signed, written consent to participate, and the time interval from labor ward arrival to randomization was set to be as short as possible to ensure an early allocation to the randomized room. The randomly computer-generated allocation list was managed by an independent agency. Information about the allocated room was printed in sealed, opaque envelopes sequentially placed in a study box at the labor ward. The recruiting care provider was not aware of the randomization sequence, and the independent agency ensured that the allocation list was followed. The women were provided with a four-digit ID code, which was printed on the sealed envelope.