Associations of pain numeric rating scale scores collected during usual care with research administered patient reported pain outcomes.

OBJECTIVE The purpose of this study is to examine the extent to which Numeric Rating Scale (NRS) scores collected during usual care are associated with more robust and validated measures of pain, disability, mental health, and health related quality of life (HRQOL). DESIGN We conducted a secondary analysis of data from a prospective cohort study. SUBJECTS We included 186 patients with musculoskeletal pain who were prescribed long-term opioid therapy. SETTING VA Portland Health Care System outpatient clinic. METHODS All patients had been screened with the 0-10 NRS during routine outpatient visits. They also completed research visits that assessed pain, mental health and HRQOL every six months for two years. Accounting for non-independence of repeated measures data, we examined associations of NRS data obtained from the medical record with scores on standardized measures of pain and its related outcomes. RESULTS NRS scores obtained in clinical practice were moderately associated with pain intensity scores (B's = 0.53-0.59) and modestly associated with pain disability scores (B's = 0.33-0.36) obtained by researchers. Associations between pain NRS scores and validated measures of depression, anxiety, and health related HRQOL were low (B's = 0.09-0.26, with the preponderance of B's < 0.20). CONCLUSIONS Standardized assessments of pain during usual care are moderately associated with research-administered measures of pain intensity and would be improved from the inclusion of more robust measures of pain-related function, mental health, and HRQOL.