Table 2 Open in new tab Quality...

First author (year)	Selection bias	Performance bias	Detection bias	Attrition bias	Reporting bias
Al Khatib (2018)²¹	L	UC	H (the term ‘sleep hygiene’ was avoided during interactions with the control group)	H	L	L
Kubo (2011)³⁶	H	N/A	H	L^a	L	L
Leproult (2015)²²	H	N/A	H	L^a	L	L
So-ngern (2019) ³⁷ and Reutrakul (2020)³⁸	L	UC	H	UC	L	L
Tasali (2014)³⁹	H	N/A	H (participants were unaware of the intervention until after the baseline)	H	L	L
Baron (2019)³⁴	L	L	H	L^a	L	L
Haack (2013)³⁵	L	UC	H	L	L	L
Arnal (2016)⁴⁰ and Chennaoui (2016)⁴¹	L	UC	H	L^a	L	L
Reynold (2014)⁴²	L	UC	H (efforts were made to avoid demand bias)	L^a	H	L
Stock (2019)⁴³	H	N/A	H	L^a	L	L
Swinbourne (2018)⁴⁴	H	N/A	H	L^a	H	L

First author (year)	Selection bias	Performance bias	Detection bias	Attrition bias	Reporting bias
Al Khatib (2018)²¹	L	UC	H (the term ‘sleep hygiene’ was avoided during interactions with the control group)	H	L	L
Kubo (2011)³⁶	H	N/A	H	L^a	L	L
Leproult (2015)²²	H	N/A	H	L^a	L	L
So-ngern (2019) ³⁷ and Reutrakul (2020)³⁸	L	UC	H	UC	L	L
Tasali (2014)³⁹	H	N/A	H (participants were unaware of the intervention until after the baseline)	H	L	L
Baron (2019)³⁴	L	L	H	L^a	L	L
Haack (2013)³⁵	L	UC	H	L	L	L
Arnal (2016)⁴⁰ and Chennaoui (2016)⁴¹	L	UC	H	L^a	L	L
Reynold (2014)⁴²	L	UC	H (efforts were made to avoid demand bias)	L^a	H	L
Stock (2019)⁴³	H	N/A	H	L^a	L	L
Swinbourne (2018)⁴⁴	H	N/A	H	L^a	H	L

Table 2

Quality appraisal (n = 13)

First author (year)	Selection bias		Performance bias	Detection bias	Attrition bias	Reporting bias
First author (year)	Randomization	Concealment	Participant blinding	Assessor blinding	Attrition bias	Reporting bias
Al Khatib (2018)²¹	L	UC	H (the term ‘sleep hygiene’ was avoided during interactions with the control group)	H	L	L
Kubo (2011)³⁶	H	N/A	H	L^a	L	L
Leproult (2015)²²	H	N/A	H	L^a	L	L
So-ngern (2019) ³⁷ and Reutrakul (2020)³⁸	L	UC	H	UC	L	L
Tasali (2014)³⁹	H	N/A	H (participants were unaware of the intervention until after the baseline)	H	L	L
Baron (2019)³⁴	L	L	H	L^a	L	L
Haack (2013)³⁵	L	UC	H	L	L	L
Arnal (2016)⁴⁰ and Chennaoui (2016)⁴¹	L	UC	H	L^a	L	L
Reynold (2014)⁴²	L	UC	H (efforts were made to avoid demand bias)	L^a	H	L
Stock (2019)⁴³	H	N/A	H	L^a	L	L
Swinbourne (2018)⁴⁴	H	N/A	H	L^a	H	L

First author (year)	Selection bias		Performance bias	Detection bias	Attrition bias	Reporting bias
First author (year)	Randomization	Concealment	Participant blinding	Assessor blinding	Attrition bias	Reporting bias
Al Khatib (2018)²¹	L	UC	H (the term ‘sleep hygiene’ was avoided during interactions with the control group)	H	L	L
Kubo (2011)³⁶	H	N/A	H	L^a	L	L
Leproult (2015)²²	H	N/A	H	L^a	L	L
So-ngern (2019) ³⁷ and Reutrakul (2020)³⁸	L	UC	H	UC	L	L
Tasali (2014)³⁹	H	N/A	H (participants were unaware of the intervention until after the baseline)	H	L	L
Baron (2019)³⁴	L	L	H	L^a	L	L
Haack (2013)³⁵	L	UC	H	L	L	L
Arnal (2016)⁴⁰ and Chennaoui (2016)⁴¹	L	UC	H	L^a	L	L
Reynold (2014)⁴²	L	UC	H (efforts were made to avoid demand bias)	L^a	H	L
Stock (2019)⁴³	H	N/A	H	L^a	L	L
Swinbourne (2018)⁴⁴	H	N/A	H	L^a	H	L

So-ngern (2019) and Reutrakul (2020) studies were from the same trial; Arnal (2016) and Chennaoui (2016) studies were from the same trial.

Objective measures were obtained.

H, high; L, low; N/A, not applicable; UC, unclear.