Efficacy of PROMIS Pain Interference and Likert Pain Scores to Assess Physical Function

The Patient Reported Outcome Measurement Information System (PROMIS), developed by the National Institutes of Health, utilizes a health domain related to Pain Interference (PI). We evaluated this domain and its association with physical function (as determined by PROMIS Physical Function [PF]), administered as a computer adaptive test (CAT), and secondarily its association to a numerical 0 to 10 pain score. Our null hypothesis was that PI, as measured by CAT, has no correlation to PF and thus, there is no difference between comparisons of numerical pain scores and PROMIS PF.

Adult patients presenting to an upper extremity clinic from February to December 2015 completed PROMIS PF, PI, and numerical 0 to 10 pain score questionnaires. The PROMIS modules were completed electronically in their computer adaptive form. Mean population scoring on each module is defined at 50. Patients were also asked to rate their pain on a 0 to 10 scale. These data were collected as routine clinical care and were extracted from the electronic health record for cross-sectional evaluation. Bivariate Pearson correlation analysis defined the association between the PROMIS modules and the numerical pain scores. Correlations between PF and PI were compared with correlations between PF and pain scores.

We recorded data from patients' 10,574 first, 5,210 second, 2,633 third, 1,382 fourth, and 722 fifth visits. The PROMIS PI was negatively correlated to the PROMIS PF. Numerical pain scores were also negatively correlated to PROMIS PF. Numerical pain scores were less correlated than PROMIS PI through time relative to PF.

Both PROMIS PI and numerical pain scores had significant correlations with PF for each office visit. The PI had a larger correlation to PF than did numerical pain scores. The PI and numerical pain scale scores are also correlated.

Patient-reported pain using a 0 to 10 pain score can be a predictor of patients' level of function, and although pain score does not replace other patient-reported outcomes, it can provide useful information, particularly when other patient-reported outcomes are not available.