CH/CC 7: Does the study adequately report on the strength of effect (e.g. ways of calculating effect size, reporting of confidence intervals)? CH/CC 8: Does the study use multivariate analysis? CH/CC 9: Is the study sample size appropriate for the analysis used? CH/CC

10: Do the authors report on the limitations of their study? CH/CC 11: Does the study report a participation rate at baseline >70 %?CH/CC 12: Does the study report attrition rates and provide evidence of comparisons of responders and non-responders? CH 13: Does the study report an attrition rate <20 %? CH 14: Does the study have CB-839 a follow up time period >6 months? CH 15: Does the study use the same population PF-562271 ic50 for cases and controls? CC 16: Are the study controls adequately (e.g. no pain for >3 months) screened for symptoms compared to cases? CC Appendix 3 See Table 4. Table 4 Data extraction tables for included studies Author (years) Country Study population Design Main study focus LBP assessment Work support assessment Findings Results Andersen et al. (2007) Denmark General workers sample Prospective cohort with a 2 year follow up Psychosocial risk factors for musculoskeletal symptoms within workers Presence of pain in previous 12 months + absence from work Danish National institute of Occupational health Questionnaire—CWS

and SS Low SS not a risk for LBP CWS as a non-significant risk factor for LBP HR 1.1 (0.8–1.6) HR 1.1 (0.8–1.6) Clays et al. (2007) Belgium General workers sample Prospective cohort over 6 years The impact of psychosocial factors on LBP Nordic questionnaire >8 days in previous 12 months Karasek Demand Control model—GWS Low GWS increased risk of LBP in men No association between GWS and risk in women RR 1.2 (1.02–1.42) RR 1.00 TCL (0.8–1.24) Dionne et al. (2007) Canada Consulters for LBP who have been absent from work

for at least 1 day Prospective BL, 6 week, 12 week, 1 year and 2 year follow ups RTW for those with LBP RMDQ, pain levels, fear avoidance Work APGAR No significant role for GWS on RTW OR 4.76 (0.43, 52.13) Elfering et al. (2002) Switzerland Workers (unspecified) Prospective cohort over 5 years Social support at work and risk of LBP Nordic questionnaire, pain frequency and intensity, RMDQ, McGill Questionnaire General questions on support in employment No significant association between low GWS and LBP N/S Feuerstein et al. (2001) USA Military personnel Case control Workplace psychosocial factors associated with NU7026 ic50 sickness absence due to LBP Self report LBP symptoms, NIOSH survey. One episode of LBP in past 12 months resulting in an episode of sickness absence Work environment scale (inclusive of one question on GWS) Participants with low GWS were at higher odds of getting LBP OR 1.22 (1.05, 1.36) Fransen et al.