Table 6.

Risk of bias summary scores (n = 119)^*†

Study (first author, year)	Item 1‡ Target population	Item 2§ Sampling frame	Item 3‖ Random selection	Item 4¶ Nonresponse bias	Item 5# Data collection	Item 6** Case definition	Item 7†† Reliability and validity	Item 8‡‡ Mode data collection	Item 9§§ Prevalence period	Item 10‖‖ Parameter calculations	Summary score (/10)	Overall category
Adegoke, 20151	1	0	0	0	0	0	0	0	0	0	1	Low
Albuquerque, 20093	1	0	0	1	1	1	0	0	0	0	4	Moderate
Al-Hashel, 20194	0	0	0	1	0	0	0	0	0	0	1	Low
Al-Khotani, 20165	1	0	0	1	0	0	0	0	0	0	2	Low
Alp, 20106	1	0	0	1	0	0	1	0	0	0	3	Moderate
Altamimi, 20147	1	0	0	0	0	0	0	0	0	0	1	Low
Al-Tulaihi, 20098	1	0	0	1	0	0	1	0	0	0	3	Moderate
Arruda, 201010	1	0	0	0	1	0	1	0	0	0	3	Moderate
Ayanniyi, 201111	1	0	0	1	0	0	0	0	0	0	2	Low
Ayonrinde, 202012	1	0	1	1	1	0	0	0	0	0	4	Moderate
Azabagic, 201613	1	0	0	1	0	1	1	0	0	0	4	Moderate
Barçak, 201515	1	0	0	0	0	0	1	0	0	0	2	Low
Bhatia, 201616	1	0	1	0	0	0	0	0	0	0	2	Low
Bouzios, 201721	1	0	0	1	1	0	0	0	0	0	3	Moderate
Buse, 201222	0	0	0	1	1	0	0	0	0	0	2	Low
Çagliyan Türk, 202024	1	0	0	1	0	0	1	0	0	0	3	Moderate
Castro, 201327	1	0	1	1	0	0	1	0	0	0	4	Moderate
Cavestro, 201428	1	0	0	1	1	0	1	0	0	0	4	Moderate
Chiwaridzo, 201431	1	0	0	0	0	0	0	0	0	1	2	Low
Chong, 201032	0	0	0	1	0	0	0	0	1	0	2	Low
Cvetkovic, 201434	1	0	0	0	0	0	1	0	1	0	3	Moderate
da Silva Jr, 2010132	1	0	0	0	0	0	1	0	0	0	2	Low
Dantas, 202135	1	0	1	1	0	1	0	0	0	0	4	Moderate
de Melo Junior, 201998	1	0	0	1	0	0	0	0	0	0	2	Low
Devanarayana, 201136	1	0	0	0	0	0	0	0	0	0	1	Low
Devanarayana, 201137	1	0	0	0	0	0	0	0	0	0	1	Low
Dhroove, 201738	1	0	0	0	0	0	0	0	0	1	1	Low
Dissing, 201739	0	0	1	1	1	0	0	0	0	0	3	Moderate
Drozda, 201140	1	0	0	1	0	1	0	0	0	0	3	Moderate
Du, 201141	0	0	0	1	1	1	1	0	0	0	4	Moderate
Durmaz, 201342	1	0	0	0	0	0	1	0	0	0	2	Low
Erdoğan, 202144	1	0	0	1	0	0	1	0	0	0	3	Moderate
Fabricant, 202045	0	0	0	1	0	1	1	0	0	0	3	Moderate
Farrant, 202346	1	0	0	1	0	1	1	0	1	1	6	High
Franco-Micheloni, 201547	1	0	0	1	0	0	0	0	0	0	2	Low
Franz, 201448	0	0	1	1	1	0	0	0	0	0	3	Moderate
Fuglkjaer, 201749	0	0	0	1	1	1	0	0	0	0	3	Moderate
Genizi, 201350	1	0	0	0	0	1	1	0	0	0	3	Moderate
Gobina, 201552	0	0	0	1	0	0	0	0	0	1	2	Low
Gobina, 201951	0	0	0	1	0	0	0	0	0	1	2	Low
Gulewitsch, 201355	1	0	1	1	1	0	0	0	1	0	5	High
Gupta, 200956	1	0	1	0	0	0	0	0	0	0	2	Low
Gustafsson, 201857	1	0	1	1	0	1	0	0	0	1	5	High
Haraldstad, 201158	1	0	0	1	0	0	0	0	0	0	2	Low
Harrison, 201659	1	0	0	1	0	0	0	0	0	0	2	Low
Heinrich, 200961	1	0	0	1	0	0	0	0	0	0	2	Low
Hoftun, 201163	1	0	0	0	0	0	0	0	0	0	1	Low
Holstein, 202065	0	0	0	0	0	0	0	0	0	0	0	Low
Holstein, 202264	0	0	0	1	0	0	0	0	0	1	2	Low
Ivanova, 202269	1	1	1	1	0	0	1	0	1	0	6	High
Jativa, 201670	1	0	1	0	0	0	0	0	0	0	2	Low
Kadim, 202172	1	0	1	0	0	0	0	0	0	0	2	Low
Kaltseis, 202273	1	0	0	1	0	0	1	0	0	0	3	Moderate
Katsuki, 202374	1	0	0	0	0	0	1	0	0	0	2	Low
Kedra, 201375	1	0	0	0	0	0	0	0	0	0	1	Low
Kedra, 201976	1	0	0	1	0	1	0	0	0	0	3	Moderate
Khayat, 202178	1	0	0	1	1	0	1	0	1	0	5	High
Knezevic-Pogancev, 201080	1	0	0	1	1	0	0	0	1	0	4	Moderate
Kolb, 202281	0	0	0	1	0	0	0	0	0	1	2	Low
Krogh, 201583	1	0	0	1	0	0	1	0	0	0	3	Moderate
Kroner-Herwig 201184	1	0	0	1	0	0	1	0	0	0	3	Moderate
Kumar, 201785	1	0	0	0	0	0	0	0	0	0	1	Low
Lipton, 201189	1	0	0	1	0	0	1	0	0	0	3	Moderate
Kemta Lekpa, 202177	1	0	0	0	0	0	0	0	0	0	1	Low
Lu, 201691	1	0	1	1	0	0	0	0	0	0	3	Moderate
Lucas, 202192	1	0	0	1	1	1	1	0	0	0	5	High
Lukaszewska, 201393	1	0	0	0	0	1	1	0	0	0	3	Moderate
Luntamo, 201294	1	0	0	0	0	1	1	0	0	1	4	Moderate
Malik, 201296	1	0	0	1	1	0	0	0	1	0	4	Moderate
Masiero, 201097	1	0	1	1	0	1	0	0	0	0	4	Moderate
Meziat Filho, 201599	1	1	1	1	0	0	0	0	0	0	4	Moderate
Meziat Filho, 2017100	1	0	1	1	0	0	0	0	0	0	3	Moderate
Mingels, 2022101	1	0	1	1	0	0	1	0	0	0	4	Moderate
Miró, 2023102	1	0	0	1	0	0	0	0	0	0	2	Low
Myrtveit, 2014104	1	0	0	1	0	1	0	0	0	0	3	Moderate
Nieswand, 2019107	1	0	1	1	0	0	1	0	0	0	4	Moderate
Noll, 2016108	1	0	0	0	0	1	0	0	0	0	2	Low
Nyame, 2010109	1	0	1	1	0	1	0	0	0	0	4	Moderate
Østeras, 2015110	1	0	1	0	0	0	1	0	0	0	3	Moderate
O'Sullivan, 2012111	1	0	1	0	0	1	0	0	0	0	3	Moderate
Oswari, 2019112	1	0	0	1	0	0	0	0	0	0	2	Low
Perera, 2016115	1	0	0	0	0	0	1	0	0	0	2	Low
Poyrazoglu, 2015117	1	0	0	1	0	0	1	0	0	0	3	Moderate
Rau, 2021118	1	0	1	1	0	0	0	0	0	0	3	Moderate
Rho, 2012119	0	0	0	0	0	0	1	0	0	0	1	Low
Saha, 2017120	1	0	0	1	0	0	0	0	0	0	2	Low
Santinello, 2009121	0	0	0	0	0	1	0	0	0	0	1	Low
Saps, 2009124	1	0	1	1	0	1	0	0	0	0	4	Moderate
Saps, 2014123	1	0	1	0	0	0	0	0	0	1	3	Moderate
Saps, 2017122	0	0	1	0	0	0	0	0	0	0	1	Low
Saps, 2018125	1	0	0	0	0	0	0	0	0	0	1	Low
Shan, 2013126	1	0	0	0	0	0	0	0	0	0	1	Low
Shaygan, 2020127	1	0	0	0	0	0	0	0	0	0	1	Low
Shuaibi, 2021129	1	0	0	1	0	0	0	0	0	0	2	Low
Sillanpaa, 2018131	1	0	0	1	0	0	1	0	0	1	4	Moderate
Siu, 2012134	1	0	0	0	0	0	0	0	0	0	1	Low
Sjölund, 2021135	1	0	0	0	0	0	0	0	0	0	1	Low
Sollerhed, 2013136	1	0	0	0	0	1	0	0	1	1	4	Moderate
Somayajula, 2022137	1	0	0	0	1	0	0	0	1	0	3	Moderate
Sperotto, 2014138	1	0	1	1	0	0	1	0	0	0	4	Moderate
Stahl, 2014139	0	0	0	1	0	1	0	0	0	1	3	Moderate
Swain, 2014140	0	0	0	1	0	0	0	0	0	1	2	Low
Torres-Ferrus, 2019142	1	0	1	0	0	0	1	0	1	0	4	Moderate
Tumin, 2018144	0	0	0	1	1	0	0	0	0	0	2	Low
Udoh, 2016146	1	0	0	0	0	0	0	0	0	0	1	Low
van den Heuvel, 202062	1	0	0	1	1	0	0	0	0	0	3	Moderate
Van Gessel, 2011147	1	0	0	1	0	0	1	0	0	0	3	Moderate
Vierola, 2012149	1	0	1	1	1	1	1	0	0	0	6	High
Vila, 2012150	1	0	0	0	0	0	0	0	0	0	1	Low
Wager, 2020151	1	0	0	1	0	0	0	0	0	0	2	Low
Walter, 2014155	0	0	0	1	0	1	1	0	0	0	3	Moderate
Wijga, 2021156	0	0	0	1	0	0	1	0	0	0	2	Low
Wilkes, 2021157	0	0	0	1	1	0	0	0	1	1	4	Moderate
Wurm, 2018161	1	0	0	0	0	0	1	0	0	0	2	Low
Yao, 2011162	1	0	1	0	0	0	0	0	0	0	2	Low
Zablah, 2015163	1	0	1	0	0	0	0	0	0	0	2	Low
Zeevenhooven, 2020165	1	0	0	1	0	0	0	0	1	0	3	Moderate
Zhang, 2015166	1	0	0	0	0	0	0	0	0	0	1	Low

^*“0” = low risk, “1” = high risk.

^†0 to 2 = low risk (further research is very unlikely to change our confidence in the estimate); 3 to 4 = moderate risk (further research is likely to have an important impact on our confidence in the estimate and may change the estimate); 5 to 10 = high risk (further research is very likely to have an important impact on our confidence in the estimate and is likely to change the estimate).

^‡Item 1: Was the study's target population a close representation of the national population in relation to relevant variables, eg, age, sex, occupation?

^§Item 2: Was the sampling frame a true or close representation of the target population?

^‖Item 3: Was some form of random selection used to select the sample, OR, was a census undertaken?

^¶Item 4: Was the likelihood of nonresponse bias minimal?

^#Item 5: Were data collected directly from the subjects (as opposed to a proxy)?

^**Item 6: Was an acceptable case definition used in the study?

^††Item 7: Was the study instrument that measured the parameter of interest (eg, prevalence of low back pain) shown to have reliability and validity (if necessary)?

^‡‡Item 8: Was the same mode of data collection used for all subjects?

^§§Item 9: Was the length of the shortest prevalence period for the parameter of interest appropriate?

^‖‖Item 10: Were the numerator(s) and denominator(s) for the parameter of interest appropriate?