CLINICAL BOTTOM LINE & AVAILABLE LITERATURE
...ABOUT THE COMPARISON OF DIFFERENT PAIN SCORES IN THE EMERGENCY DEPARTMENT: IS ONE BETTER?
CLINICAL BOTTOM LINE
A total of 6 studies compared different pain scores in the Emergency Department.
Of these studies, one had level of evidence 2b and the rest had level of evidence 4.
In all studies the study populations consisted of:
- pain of any cause / mixed study populations (2093 patients)
In all studies, NRS was directly compared to VAS pain scores. One study also compared a plastified VAS to the original VAS pain scoring tool. One study compared a Color Analog Scale (CAS) to VAS and NRS.
Taken together, it can be concluded* that...
1. VAS and NRS pain scores are strongly correlated when used in the Emergency Department.
Level of recommendation C
All studies found excellent correlation. Two remarks have to be made here:
1. Several different statistical methods were used to analyse correlation and agreement.
2. NRS pain scores had slightly wider limits of agreement in the range of 40-100U in one study and the results of 1 study suggested that NRS overestimated severe pain and underestimated mild pain.
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2. CAS is closely correlated with both VAS and NRS pain scores in the Emergency Department.
Level of recommendation C
This was evaluated in one cross-sectional study in 150 patients.
3. NRS is easier to use in the Emergency Department and better reflects actual pain according to patients
Level of recommendation C
Patients' preferences were evaluated in four studies. The majority found NRS easier to use than VAS (35% and 61%, versus 18% and 22%, respectively in two different studies). Using NRS pain scores led to a lower non-response rate in one study.
In another study, NRS better reflected actual pain than VAS did: 53% versus 26%.
* Disclaimer:
Included studies were different in several items, such as timing and methods of measurement of several endpoints; study population and baseline situation. Due to these large differences in study methodology, results cannot be pooled and the level of recommendation should be regarded as an estimation of the true effect. The levels of recommendation were derived according to the OCEBM levels of evidence.
The included studies were found using PubMed (Medline) and Embase with the following search terms and synonyms: pain AND (scale OR score OR measure) AND emergency. The search was updated in September 2020.
Several studies evaluated convenience samples of patients and ED crowding might have led to missed inclusions (and then probably especially at the extremes of pain intensity). Both factors might have confounded study results.
Some studies used alternated orders in administering pain scores and some studies always used the same order of pain scores. Using the latter technique might bias results, as patients know how to score their pain and understand pain scores better after having recorded the first pain score. This might have influenced study results as well.
Available literature on comparison of pain scores: