Fig. 2From: Comparison of preemptive paracetamol, paracetamol-diclofenac & paracetamol-tramadol combination on postoperative pain after elective abdominal surgery under general anesthesia, Ethiopia: a randomized control trial study, 2018Numerical pain rating scale (NRS), adopted from the National Initiative on Pain Controlâ„¢ (NIPCâ„¢)Back to article page