EUROSPINE's tool of choice for low back pain evaluation
The development of the Core Outcome Measures Index-back (COMI-back) was an attempt to standardize patient-reported outcome measures to a few core items that were recommended by an international group of back pain researchers named the European Spine Study Group. The measure is part of EUROSPINE’s spine tango, an international registry to collect data from patient-reported outcome measures for clinical studies and research.
Although the questionnaire consists of only 6 questions, many dimensions are covered within this outcome measure (pain intensity, back-related function, symptom-specific well-being, general quality of life, social disability and work disability). The COMI-back questionnaire has been used in studies of patients with spinal deformities and lumbar spinal stenosis and has been proved a validated tool for back pain evaluation.
Items - Dimensions - Completion time
In the core COMI-back, 1 question consists of 2 numerical rating scales to be answered from 0 to 10 and 5 questions to be answered by selecting 1 of 5 response options.
The EUROSPINE and Deutsche Wirbelsäulengesellschaft versions have 5 additional questions on pain quality and patient satisfaction with the treatment and outcome. The additional questions do not influence the COMI-back score.
The 6 items cover 5 dimensions: pain intensity (back and leg pain), back-related function, symptom-specific well-being, general quality of life and disability (social and work). The patient is asked to answer based on how he or she has felt for the last week, except for the disability dimensions, for which the patient is asked to answer based on how he or she has felt for the last 4 weeks.
There is no information in the literature on completion time. We estimate a time of approximately 5 minutes.
Each dimension receives a subscore. The higher of the 2 pain intensity scores forms the pain intensity dimension subscore. Each response for each of the other 5 questions is scored from 0 to 10:
response 1 (associated with the best possible health status): 0 points
response 2: 2.5 points
response 3: 5 points
response 4: 7.5 points
response 5 (associated with the most health limitations): 10 points
The average of the 2 disability scores forms the disability dimension subscore.
A total COMI score is determined by averaging the 5 dimension scores. There is no information on how to deal with missing data or skipped questions. 4
Question 1: 5 and 4 points respectively (the higher value of 5 is used for scoring)
Question 2: response 4 (7.5 points)
Question 3: response 2 (2.5 points)
Question 4: response 2 (2.5 points)
Question 5: response 1 (0 points)
Question 6: response 4 (7.5 points)
COMI score: (5+7.5+2.5+2.5+((0+7.5)/2))/5 = 4.25
The lower the score, the better the patient’s health.
The lowest possible score of 0 points is associated with no loss of health or function and no pain, whereas the maximum score of 10 points represents the most severe back pain and loss of function.