Table 1

Characteristics of included Studies on causes of LBP

First author, Year, CountryStudy designAnticipated finding(s) based on the study aim(s)Recall period for LBP DefinitionaAccording to authors or obvious from text:
1st time episode, Episode, or Prevalence b		Definition of preceding non-episodecRisk factor data collected prior to the onset of LBP variable
Aggarwal 2013
India [28]		Cross-sectionalPrevalence, associated risk factors1 yearPrevalenceNoneNo
Alperovitch 2010
Israel [29]		Cross-sectionalPrevalence, associated risk factors1 yearPrevalenceNoneNo
Auvinen 2010
Finland [30]		LongitudinalRisk factors6 monthEpisodeNo LBP previous 6 month at 16 & 18Yes for the 2nd survey
Capkin 2015
Turkey [31]		Cross-sectionalPrevalence, risk factorsLifetime, 1 yearPrevalenceNANo
Cho 2012
South Korea [32]		Cross-sectionalPrevalence, risk factorsLifetime, Point, 6 monthPrevalenceNANot clear
Coenen 2013
the Netherlands [33]		Prospective cohortAssociated risk factor1 yearPrevalenceNANot clear
Erick 2014
Botswana [34]		Cross-sectionalPrevalence, risk factors1 yearPrevalenceNANo
Ernat 2012
North America [35]		Retrospective, Database analysisIncidence, risk factorsNAInitial visit for lumbagoNANo
Gaowgzeh 2015
Saudi Arabia [36]		Cross-sectionalPrevalence, risk factorsUndefinedPrevalenceNoneNo
Jia 2016
China [37]		Cross-sectionalPrevalence, risk factors1 yearPrevalenceNANo
Kanchanomai 2015
Thailand [38]		ProspectiveAnnual incidence, risk factors3 monthIncidenceNoneNot clear
Katsavouni 2014
Greece [39]		Cross-sectionalRisk factors1 yearPrevalenceNANo
Knox 2014
North America [40]		Retrospective Database analysisIncidence, risk factorsNAFirst diagnosis of LBPNANo
Lin 2014
Taiwan [41]		Cross-sectionalPrevalence, risk factors1 yearPrevalenceNANo
Lin 2012
Taiwan [42]		Cross-sectionalPrevalence, risk factorsLifetime, pointPrevalenceNANo
Mikkonen 2016
Finland [43]		Prospective cohortRisk factors6 monthEpisodeNo LBP past 6 month at 16 & 18Yes for the 2nd survey
Mitchell 2010
Australia [44]		ProspectiveRisk factors predicting new-onset LBPLife-time, 1 yearEpisodeNo significant LBP at baselineYes
Mohseni-bandpei 2011
Iran [45]		Cross-sectionalPrevalence, risk factorPoint, 1 month, 6 month, year, lifetimePrevalenceNANo
Murtezani 2011
Kosovo [46]		Cross-sectionalPrevalence, risk factors1 yearPrevalenceNANo
Ng 2014
Australia [47]		Cross-sectionalPrevalence, risk factorsLifetime, pointPrevalenceNANo
Nissen 2014
Denmark [48]		RetrospectiveAssociated Risk factors1 yearPrevalenceNANo
Noda 2015
Sri Lanka [49]		Cross-sectionalPrevalence, risk factors4 weeksPrevalenceNANo
Ramond-Roquin 2015 France [50]Prospective cohortRisk factors1 weekPrevalence, episodeNAYes for the 2nd survey
Shemory 2016
North America [51]		Retrospective Database analysisRisk factorsNAIncidenceNANo
Sikiru 2010
Nigeria [52]		Cross-sectionalPrevalence, risk factors1 yearPrevalenceNANo
Steffens 2015
Australia [53]		Case-crossoverRisk factorsNAEpisodeFree of pain in the past monthNo/purposely retrospective
Sterud 2013
Norway [54]		ProspectiveRisk factors4 weeksPrevalenceNANo
Triki 2015
Tunisia [55]		RetrospectivePrevalenceNo LBP before current injuryFirst LBP injuryNANo
van Hilst 2015
the Netherlands [56]		Cross-sectionalPrevalence, associated risk factors1 yearPrevalenceNANo
Vandergrift 2012
North America [57]		ProspectiveRisk factors1 yearEpisodePain-free at baselineYes for the follow-up survey
Vargas-Prada 2013
Spain [58]		ProspectiveIncidence, risk factors1 yearEpisodeFree of pain in the past monthYes for the follow-up survey
Vilar Furtado 2014
Brazil [59]		Cross-sectionalRisk factors3 monthPrevalenceNANo
Yue 2012
China [60]		Cross-sectionalPrevalence, risk factors1 yearPrevalenceNANo
aThe period in which an episode of LBP was investigated for its risk factors

b1st time episode: when the very first episode of LBP was investigated, Episode: when any pain-free period preceding the recurrent episode under scrutiny could be identified, and Prevalence: when explicitly stated by authors or based on their objectives and method a mixture of all types of LBP was investigated

cAn application of a pain-free period preceding the episode under scrutiny