Feasibility of assessing patients' acceptable pain in a randomized controlled trial on a patient pain education program.

Background: For patients with cancer-related pain, the numeric rating scale is the most frequently used instrument to measure pain intensity. In the literature, it has been suggested to interpret patient-reported ratings of pain in relation to the pain intensity which is acceptable to the individual patient.
Aim: We aimed to examine the feasibility and course of acceptable pain intensity.
Design: A secondary analysis of a randomized controlled trial that tested the effectiveness of standard care versus standard care supplemented by a pain consultation combined with a patient pain education program.
Setting: A total of 72 patients were included from an outpatient oncology clinic of a university hospital. They were diagnosed with cancer-related nociceptive pain with an average pain intensity ⩾4.
Results: Most patients (97%) were able to give a score for acceptable pain. Almost half of the patients scored their acceptable pain in the range of moderate to severe. Patients' ratings of acceptable pain were stable; after 8 weeks, 69% of patients had a variation of up to 1 point compared to baseline. However, the mean acceptable pain intensity remained equal in the standard care group (from 4.6 (range: 0-8) to 5.0 (range: 2-8)) and decreased in the intervention group (from 4.6 (range: 2-8) to 3.8 (range: 0-7, p < 0.01), difference between groups p < 0.05).
Conclusion: Measurement of acceptable pain intensity is feasible. Patients with additional pain treatment became more critical and accepted less pain. More research is needed before we can use acceptable pain intensity as a reference for the interpretation of pain ratings.