Summary of GRADE Rating of Included Comparative Studies of MIS Versus Open Transforaminal

Appendix 3

Summary of GRADE Rating of Included Comparative Studies of MIS Versus Open Transforaminal or Posterior Lumbar Interbody Fusion

Study / Study design / Initial GRADE rating / Limitations in study design / Inconsistency of results / Precision / Indirectness of evidence / Final GRADE rating
Adogwa et al. [1] / Retrospective cohort / Low / No significant limitations / None / Poor: small number / None / Low
Bagan et al. [3] / Retrospective cohort / Low / Unclear selection criteria / None / Poor: small number / Undifferentiated outcome: heterogeneous population
Unequal number of revision cases in cohorts / Very low*
Dhall et al. [10] / Retrospective cohort / Low / Different followup between cohorts
Unclear selection of surgical technique / None / Poor: small number / Undifferentiated outcome: heterogeneous population / Very low*
Fan et al. [11] / Prospective cohort / Low / Surgical technique chosen by patient / None / Poor: small number / Undifferentiated outcome: heterogeneous population / Very low
Gahreman et al. [12] / Prospective cohort / Low / Surgical technique chosen by patient / None / Poor: small number / None / Very low*
Harris et al. [15] / Retrospective cohort / Low / Unclear loss to followup
Unclear selection of surgical technique / None / Poor: small number / None / Very low
Isaacs et al. [16] / Retrospective cohort / Low / No significant limitations / None / Poor: small number / Undifferentiated outcome: heterogeneous population / Very low*
Kotani et al. [18] / Prospective cohort / Low / Unclear consecutive enrollment
Unclear loss to followup
Surgical technique chosen by patient / None / Poor: small number / None / Very low
Lau et al. [19] / Retrospective cohort / Low / Surgical technique chosen by patient / None / Poor: small number / Undifferentiated outcome: heterogeneous population / Very low*
Lee et al. [20] / Prospective cohort / Low / No significant limitations / None / Acceptable / Undifferentiated outcome: heterogeneous population / Low
Mobbs et al. [22] / Prospective cohort / Low / Unclear consecutive enrollment
Large loss to followup in open cohort
Surgical technique dictated by payment / None / Acceptable / Undifferentiated outcome: heterogeneous population / Very low
Ntoukas and Muller [24] / Retrospective cohort / Low / Unclear consecutive enrollment
Unclear selection of surgical technique / None / Poor: small number / Undifferentiated outcome: heterogeneous population / Very low
Park and Ha [27] / Prospective cohort / Low / Surgical technique dictated by payment / None / Poor: small number / Undifferentiated outcome: heterogeneous population / Very low*
Pelton et al. [28] / Retrospective cohort / Low / Unclear loss to followup
Unclear selection of surgical technique
Short followup for clinical outcome / None / Poor: small number / Undifferentiated outcome: heterogeneous population / Very low*
Peng et al. [29] / Retrospective cohort / Low / Unclear consecutive enrollment
Unclear loss to followup
Unclear selection of surgical technique / None / Poor: small number / Undifferentiated outcome: heterogeneous population / Very low
Rampersaud et al. [31] / Retrospective cohort / Low / No significant limitations / None / Poor: small number / None / Low
Scheufler et al. [33] / Retrospective cohort / Low / No significant limitations / None / Poor: small number / Undifferentiated outcome: heterogeneous population / Low*
Schizas et al. [34] / Prospective cohort / Low / Unclear loss to followup
Surgical technique dictated by diagnosis / None / Poor: small number / Undifferentiated outcome: heterogeneous population / Very low
Starkweather et al. [35] / Prospective cohort / Low / Unclear consecutive enrollment
Unclear enrolment criteria / None / Poor: small number / Heterogeneity of cohorts unclear / Very low*
Tsutsumimoto et al. [39] / Retrospective cohort / Low / Nonconsecutive patients
Historical control group / None / Poor: small number / None / Very low*
Villavicencio et al. [40] / Retrospective cohort / Low / No significant limitations / None / Undifferentiated outcome: heterogeneous population / Low*
Wang et al. [41] / Prospective RCT / High / Sample size not calculated
Unclear consecutive enrollment
Unclear allocation concealment
Blinding not reported
Intention-to-treat analysis not reported / None / Acceptable / Undifferentiated outcome: heterogeneous population / Low*
Wang et al. [42] / Prospective cohort / Low / Unclear loss to followup
Unclear selection of surgical technique / None / Poor: small number / Undifferentiated outcome: heterogeneous population / Very low
Wang et al. [43] / Prospective cohort / Low / Unclear loss to followup / None / Acceptable / None / Low
Wang et al. [44] / Prospective cohort / Low / Unclear loss to followup / None / Poor: small number / Undifferentiated outcome: heterogeneous population / Very low
Wang et al. [45] / Retrospective cohort / Low / Surgical technique dictated by presentation / None / Poor: small number / Undifferentiated outcome: heterogeneous population / Very low*

*GRADE rating assessed based on examination of perioperative process measures; MIS = minimally invasive surgery; RCT = randomized controlled trial.