Preoperative opioid use is associated with worse patient outcomes after Total joint arthroplasty: a systematic review and meta-analysis

Table 2 JBI risk of bias quality assessment for cohort studies

Study	Q1^a	Q2	Q3	Q4	Q5	Q6	Q7	Q8	Q9	Q10	Q11	% yes	Risk^b
Zywiel et al.	✕	✓	✓	✓	✕	✓	✓	✓	?	✕	✕	55%	Moderate
Smith et al.	✕	✕	✕	✓	✓	✓	✓	✓	?	✕	✓	55%	Moderate
Franklin et al.	?	✕	✕	✕	✕	✓	✓	✓	✕	✕	✕	27%	High
Pivec et al.	✕	✓	✓	✓	?	✓	✓	✓	?	✕	✕	55%	Moderate
Nguyen et al.	?	✓	✓	✕	✕	✓	✓	✓	?	✕	✕	45%	High
Goesling et al.	✕	✓	✕	✓	✕	✓	✓	✓	?	✕	✕	45%	High

Abbreviations
JBI Joanna Briggs Institute
^aQ1 – Q11 indicate questions 1 to 11 based on the JBI risk assessment (Additional file 1: Appendix B).
Notes
^bThe risk of bias was ranked as high when the study reached up to 49% of “yes” scores, moderate when the study reached from 50 to 69% of “yes” scores, and low when the study reached more than 70% of “yes” scores. ‘✓’ indicates yes, ‘✕’ indicates no and ‘?’ indicates unclear.