Pain Scores Show No Monotonic Upwards or Downwards Trend Over Nine Years at a Single Institution
Lovett PB, Jerusik BC, Bernard SL, Mathew RG, Randolph FT
Thomas Jefferson University Hospitals, Philadelphia, PA
Background: Self-reported pain scales are commonly used in emergency department (EDs). The 11-point (0 to 10) Numerical Rating Scale (NRS) is a commonly used scale for adults visiting EDs in the US. Despite their widespread use little is known about whether distribution of pain scores has remained consistent over time.
Study Objectives: To describe changes in the distribution of NRS pain scores over time at one hospital.
Methods: Retrospective chart review for the years 2003-2011. All pain scores for May 1st and 2nd of those years were collected. Multinomial logistic regression was used to model the probability of a patient rating their pain in each of 11 categories (scores 0 to 10) as a function of the calendar year. Additional analysis was carried out with pain scores grouped into 4 categories (no pain: score 0, low pain: 1-4, moderate pain: 5-7, and severe pain: 8-10). Both linear and quadratic terms for time were assessed.
Results: Data from 2,136 patients over a 9 consecutive year period was collected. The pain score distribution differed significantly over time (p 0.001), although there was not a clear monotonic trend. A simple linear trend of the changes in pain scores over time was not significant (p 0.704), but the addition of a quadratic trend over time was significant (p 0.013). Figure 1 shows the smoothed cumulative proportions for no pain, low pain, and moderate pain. This was estimated from the model by using the quadratic time pattern. These results suggest that pain scores tended to be lower at the beginning and end of the study period.
Conclusion: While there are significant shifts in pain scores over time there is not a significant single-direction trend. At this hospital, there was no “inflation” or “deflation” in pain scores over time. It is important for researchers examining pain scores over large time periods to be aware of shifts in distribution such as are reported here, even when those shifts do not fall in a single direction.
- pain scores,
Available at: http://works.bepress.com/paris_lovett/6/