Figure 2 presents a diagram of how the Ottawa Method is carried out. The figure is further described in detail in the main body of the report, “Method I involved detection of qualitative and/or quantitative signals indicating the need for updating through the assessment of new evidence using specific categories for qualitative (A1-A7) and quantitative (B1-B2) signals as reported in Table 1. For example, a qualitative signal was considered a finding from a newly published pivotal trial which was opposite to that of the CER with respect to an efficacy outcome (e.g., effective vs. ineffective or vice-versa) or harm (e.g., risk of harm outweighs the previously observed benefits), a superior new treatment (e.g., new treatment significantly more effective than one assessed in the CER), or a new subgroup of population (the treatment assessed in the CER has been expanded to a new subgroup of participants). An example of a quantitative signal is the incorporation of a new trial (or trials) into a meta-analysis of the CER leading to an overturn of a statistically non-significant pooled estimate into a statistically significant one or vice-versa.”

Figure 2Ottawa method

From: Methods

Cover of Surveillance and Identification of Signals for Updating Systematic Reviews: Implementation and Early Experience
Surveillance and Identification of Signals for Updating Systematic Reviews: Implementation and Early Experience [Internet].
Newberry SJ, Ahmadzai N, Motala A, et al.
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