Measuring pain in oncology outpatients: Numeric Rating Scale versus acceptable/non acceptable pain. A prospective single center study

Objectives During all stages of oncologic diseases, pain is still a major problem. The Numeric Rating Scale (NRS) is one of the most frequently used tools for pain assessment, although interpretation is difficult. The main objective of this study is to compare two types of pain evaluation scales: NRS versus (non) acceptable pain evaluation scale. The secondary aim is to analyze a 10% sample of patients indicating non acceptable pain more in-depth. Methods To assess the pain evaluation scales, a prospective observational study, with a nested retrospective in-depth exploration, was conducted. One-year data of patients visiting the outpatient clinic of the oncology center of a university hospital were used. Besides the pain scores of all patients, a 10% sample of patients indicating non acceptable pain was analyzed more in-depth. Results During 1 year, a total of 37,580 patients registered at the outpatient clinic, of whom approximately 10% indicated non acceptable pain. The mean NRS of patients indicating non acceptable pain was 6.5 (n = 2153). For patients indicating acceptable pain, the mean NRS was 1.6 (n = 21,010). Although the presence of pain recorded in the patient record increased substantially over the year, the percentage of reported interventions only slightly increased. Conclusion The (non) acceptable pain evaluation seems a valuable addition to the NRS for assessing pain among patients with cancer. As interpretation of the NRS appears to be difficult, using the (non) acceptable pain evaluation is recommended. Moreover, creating awareness among specialists to discuss pain has a positive effect on the amount of pain discussed during consultation.