Background: In postoperative pain treatment patients are asked to rate their pain
experience on a single uni-dimensional pain scale. Such pain scores are also used as
indicator to assess the quality of pain treatment. However, patients may differ in how they
interpret the Numeric Rating Scale (NRS) score.
Objectives: This study examines how patients assign a number to their currently
experienced postoperative pain and which considerations influence this process.
Methods: A qualitative approach according to grounded theory was used. Twenty-seven
patients were interviewed one day after surgery.
Results: Three main themes emerged that influenced the Numeric Rating Scale scores
(0–10) that patients actually reported to professionals: score-related factors, intrapersonal
factors, and the anticipated consequences of a given pain score. Anticipated consequences
were analgesic administration—which could be desired or undesired—and possible
judgements by professionals. We also propose a conceptual model for the relationship
between factors that influence the pain rating process. Based on patients’ score-related
and intrapersonal factors, a preliminary pain score was ‘‘internally’’ set. Before reporting
the pain score to the healthcare professional, patients considered the anticipated
consequences (i.e., expected judgements by professionals and anticipation of analgesic
administration) of current Numeric Rating Scale scores.
Conclusions: This study provides insight into the process of how patients translate their
current postoperative pain into a numeric rating score. The proposed model may help
professionals to understand the factors that influence a given Numeric Rating Scale score
and suggest the most appropriate questions for clarification. In this way, patients and
professionals may arrive at a shared understanding of the pain score, resulting in a tailored
decision regarding the most appropriate treatment of current postoperative pain,
particularly the dosing and timing of opioid administration.