Table 3.

Modified version of the OHAT pre‐defined algorithm

Tier 1	Study must be rated as “definitely low” ++ or “probably low” + risk of bias for all key criteria AND have most other applicable criteria rated as “definitely low” ++ or “probably low” + risk of bias.	Low RoB
Tier 2	Study does not meet criteria for Tier 1 or Tier 3.	Moderate RoB
Tier 3	Study must be rated as “definitely high” ‐‐ or “probably high” ‐/NR risk of bias for most (at least two) key criteria AND have most other applicable criteria rated as “definitely high” ‐‐ or “probably high” ‐/NR risk of bias.	High RoB