Postoperative pain assessment based on numeric ratings is not the same for patients and professionals: a cross-sectional study

Abstract

Background: Numeric pain scores have become important in clinical practice to assess postoperative pain and to help develop guidelines for treating pain. Professionals need the patients' pain scores to administer analgesic medication. However, do professionals interpret the pain scores in line with the actual perception of pain by the patients?

Objective: The study aim was to assess which Numerical Rating Scale (NRS) pain score was considered bearable on a Verbal Rating Scale (VRS) by patients and professionals.

Methods: This prospective study examined the relationship between the Numerical Rating Scale and a Verbal Rating Scale. The patients (n=10,434) rated their pain the day after surgery on the 11-point NRS (0=no pain and 10=worst imaginable pain) and a VRS comprising five descriptors: "no pain"; "little pain"; "painful but bearable"; "considerable pain"; and "terrible pain". The first three categories together ("no pain", "little pain" and "painful but bearable") were considered "bearable" and the last two categories ("considerable pain" and "terrible pain") were deemed as "unbearable" pain. The professionals (n=303) were asked to relate the numbers of the NRS to the words of the VRS.

Results: Most patients considered NRS 4-6 as "bearable" pain. Among professionals, anesthesiologists, Post Anaesthesia Care nurses, and ward nurses interpreted NRS scores in the same way as the patients. Only the Acute Pain Nurses interpreted the scores differently; they considered NRS of 5 and higher to be not bearable.

Conclusions: Some care providers and patients differ in their interpretation of the postoperative NRS scores. A risk of overtreatment might arise when health care providers rigidly follow guidelines that prescribe strong analgesics for pain scores above 3 or 4 without probing the patient's preference for pharmacological treatment.

Trial registration: ClinicalTrials.gov NCT00293618.