The threshold for pain interfering with daily activities was reported to be 3 on a 0 to 10 numeric rating scale by patients with rheumatoid arthritis (RA), according to study results published in Arthritis Care and Research.
Patients in the National Databank for Rheumatic Diseases were asked to complete 8 items from the Patient-Reported Outcomes Measurement Information System Pain Interference Item Bank in which they were asked about pain interference during daily activities (on a scale of “not at all” to “very much”).
A total of 3949 patients with RA completed the questionnaire (response rate, 82%; average age, 65.4±11.9 years; 83.5% women; average RA duration, 21.7±12.6 years).
A majority of participants reported “not at all” or “a little bit” of pain interference with a daily activity. Pain interference was most common for daily activities and least common for the ability to concentrate (76.2% and 51.3%, respectively).
Scores of noninterfering pain covered the whole range of the pain numeric rating scale for each item. The mean pain level at which participants indicated being able to pursue any activity they wished to pursue was 2.3±1.9. The mean level at which pain no longer interfered with specific activities ranged from 2.7±2.1 for the ability to fall and stay asleep, to 3.1±2.0 for social activities.
An increase in intense pain was the only parameter identified as being associated with higher noninterfering pain levels (a 1-unit increment in pain intensity was associated with an increment of 0.2-unit of noninterfering pain levels). A larger percentage of patients with high vs moderate or low pain intensity reported higher noninterfering pain levels.
Study limitations included a lack of data on tender and swollen joint counts and the fact that participants were asked to compare their current pain levels with those from 6 months prior.
“Over half of patients with RA reported that pain interfered with function, most commonly affecting daily activities,” the researchers concluded. “These data highlight the importance of effective pain management, with a goal of reducing pain levels to less than 3 out of 10.”
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Lee YC, Katz P, Quebe A, et al. Defining pain that does not interfere with activities among rheumatoid arthritis (RA) patients [published online February 14, 2020]. Arthritis Care Res. doi:10.1002/acr.24170