How did Fleet and colleagues use triangulation to determine clinically significant pain reduction in their study?

Fleet and colleagues triangulated existing MIC benchmarks by reviewing four earlier anchor-based studies that established the minimal important change on a VAS for pain as ranging from 0.9 to 1.3 cm, and they used a reduction of 1.2 cm as their benchmark for clinically significant improvement. Applying that threshold, they concluded that 78% of the women in their sample had a clinically significant reduction in pain.

In the discussion of triangulation for clinical significance, the textbook describes Fleet and colleagues as an example of researchers who used existing benchmarks rather than conducting new MIC research. Their study examined the effect of subcutaneous fentanyl in childbirth on pain scores measured with a 100-cm visual analog scale. Fleet and colleagues reviewed findings from four earlier studies, all of which had used an anchor-based approach to establish the MIC for pain reduction on a VAS. Those studies produced MIC estimates ranging from 0.9 to 1.3 cm, so Fleet and colleagues used 1.2 cm as their threshold. By integrating these multiple anchor-based estimates into a single benchmark, they determined that 78% of the women achieved a clinically significant pain reduction. This illustrates an evaluative use of triangulation based on existing published MIC values rather than combining a distribution-based method with an anchor-based method.