Cluster 132: study increase interpretation associated results participation interfere abnormality risk inappropriate 
Cluster 917: increase risk medical toxicity opinion condition investigator patients potentially illness 
Cluster 1937: substantially increase judgment risk associated participation investigator condition illness major 
Cluster 2268: impair study opinion participation investigator medical uncontrolled disorder increase associated 
Cluster 2294: acidosis lactic metabolic history metformin associated risk meq alcoholic beverages