Updated 2020-Oct-13 06:36 drawing code hived off, calculations updated, previous values pulled. Please not in order to pull previous values add measurements must be made. Based on the form by Charles S. Cleeland PhD and the Pain Research Group. The Brief Pain Inventory - Short Form - to be included with the referral to the Fraser Health Pain Clinic. With Calculators for the PEG score (average PAIN, ENJOYMENT of life, and GENERAL activity), the Severity score (Measuring the Worst and Least pain in the last 24 hours with the Average pain and the Current Pain - 4 measurements) and the Interference Score ( 7 items ).