Conservative management of spinal pathology with autologous conditioned serum: A systematic review of the literature

Table 1 Risk of bias assessment

Manuscript type	Ref.	Related questions													Total	Risk of bias
Randomized control trial		Was true randomization used for assignment of participants to treatment groups?	Was allocation to treatment groups concealed?	Were treatment groups similar at the baseline?	Were participants blind to treatment assignment?	Were those delivering the treatment blind to treatment assignment?	Were treatment groups treated identically other than the intervention of interest?	Were outcome assessors blind to treatment assignment?	Were outcomes measured in the same way for treatment groups?	Were outcomes measured in a reliable way?	Was follow-up complete and if not, were differences between groups in terms of their follow-up adequately described and analyzed?	Were participants analyzed in the groups to which they were randomized?	Was appropriate statistical analysis used?	Was the trial design appropriate and any deviations from the standard randomized control trial design (individual randomization, parallel groups) accounted for in the conduct and analysis of the trial?
	Godek et al[13]	Y	Y	Y	Y	N	Y	N	Y	Y	Y	Y	Y	Y	85%	Low
Cohort studies		Were the two groups similar and recruited from the same population?	Were the exposures measured similarly to assign people to both exposed and unexposed groups?	Was the exposure measured in a valid and reliable way?	Were confounding factors identified?	Were strategies to deal with confounding factors stated?	Were the groups/participants free of the outcome at the start of the study (or at the moment of exposure)?	Were the outcomes measured in a valid and reliable way?	Was the follow-up time reported and sufficient to be long enough for outcomes to occur?	Was follow-up complete, and if not, were the reasons for loss to follow-up described and explored?	Were strategies to address incomplete follow-up utilized?	Was appropriate statistical analysis used?	N/A	N/A
	Becker et al[15]	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	N/A	N/A	100%	Low
	Goni et al[16]	Y	Y	Y	N	N	Y	Y	Y	Y	Y	N	N/A	N/A	73%	Low
	HS et al[17]	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	N/A	N/A	100%	Low
	Godek et al[19]	Y	Y	Y	N	N	Y	Y	Y	Y	Y	Y	N/A	N/A	82%	Low
	Godek et al[18]	Y	Y	Y	N	N	N	Y	Y	Y	Y	Y	N/A	N/A	73%	Low