Table 2.

Summary of study designs and key variables.

	Richardson et al 2010	Narangerel et al 2007	Meyer and Erler 2011	McRury and Zolotor 2010	Kelmanson 2013	Öztürk and Bayik 2019
Randomised controlled trial			X	X
Quasi-experimental	X	X			X	X
Outcomes assessed by	Objective measurement	Objective measurement	Objective measurement	Self report	Self report	Self report
Period of sleep (nocturnal or diurnal) stated	X		X	X	X	X
Study environment	Lab	Home	Lab	Home	Home	Home
Swaddle technique detailed	X	X
Environmental temperature detailed	X	X
Feeding method detailed	X					X
Swaddle tightness measured