Background & Aims

An adequate pain management demands an accurate assessment of its intensity. There are objective scales to measure the degree of pain reported by patients, two of the most common are the Verbal Rating Scale (VRS) and the Numerical Rating Scale (NRS). Classically, there is a degree equivalence between the two scales, in which 0 on the numerical scale would correspond to no pain on the verbal scale, 1-3 would correspond to mild pain, 4-6 would correspond to moderate pain and, finally, 7-10 would correspond to severe pain. However, this theoretical equivalence does not always seem to be accurate, even with the patient’s understanding of the scales. This study aims to verify the relationship between the NRS and the VRS for patients admitted to a quaternary pain service.

Methods

Participants were recruited among patients followed by the Pain Control Group of the Hospital das Clínicas da Universidade de Sao Paulo (HC-FMUSP). The inclusion criteria were patients over 18 years old that agreed to participate in the study and that signed the informed consent form. Exclusion criteria were patients who refused to participate in the study, mental confusion or not understanding the scales used after explanation by the research team. Eligible patients were identified by the medical and nursing team, and informed about the research protocol. If there was agreement to participate, free and informed consent was obtained by a researcher. The patients were followed for 3 days and asked daily to report their pain intensity using the VRS and the NRS. Demographic and background, as well as pain characterization data were collected.

Results

A total of 70 patients were enrolled, over 60% male patients. Both acute and chronic pain patients were interviewed about their pain score, the majority of participants were unemployed and suffered from chronic localized pain. Considering the classic cutoff 1-3 mild, 4-6 moderate and 7-10 severe, there was a correlation between the NRS and the patients’ subjective qualification of 0.88. However, there was a correlation of 0.94 with the cutoff to 1-5 mild, 6-7 moderate and 8-10 strong, which shows a superiority compared to the classical scale. Also, this study found that the variables “Acute pain vs. chronic pain” and “Pain in three or more body regions” influence the perception of pain by the VRS with statistical relevance (p<0.05).

Conclusions

According to the data obtained and the analyzes carried out, there was a discrepancy found between the interpretation of pain levels in our population and the classic cutoffs that correlates the Numerical Rating Scale and the Verbal Rating Scale. The question arises whether the new cuts established to compare these scales are a better option than the standard. Even with limitations, it was possible to observe a significant difference in the perception of pain in patients with chronic and acute conditions, and patients with diffuse or localized pain. Thus, opening the question for new studies to scrutinize the origin of these differences.

References

GBD 2016 Disease and Injury Incidence and Prevalence Collaborators. Global, regional, and national incidence, prevalence, and years lived with disability for 328 diseases and injuries for 195 countries, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet. 2017 Sep 16;390(10100):1211-1259.

Sessle B. Unrelieved pain: a crisis. Pain Res Manag. 2011 Nov-Dec;16(6):416-20.

Gregory J, McGowan L. An examination of the prevalence of acute pain for hospitalised adult patients: a systematic review. J Clin Nurs. 2016 Mar;25(5-6):583-98.

Aguiar DP, Souza CPQ, Barbosa WJM, Santos-Júnior FFU, de Oliveira AS. Prevalence of chronic pain in Brazil: systematic review. BrJP. 2021 Jul-Sep;4(3):257-267

Karcioglu O, Topacoglu H, Dikme O, Dikme O. A systematic review of the pain scales in adults: Which to use? Am J Emerg Med. 2018 Apr;36(4):707-714.

Chien CW, Bagraith KS, Khan A, Deen M, Strong J. Comparative responsiveness of verbal and numerical rating scales to measure pain intensity in patients with chronic pain. J Pain. 2013 Dec;14(12):1653-62.

Williamson A, Hoggart B. Pain: a review of three commonly used pain rating scales. J Clin Nurs. 2005 Aug;14(7):798-804.

Katz J, Melzack R. Measurement of pain. Surg Clin North Am. 1999 Apr;79(2):231-52. doi: 10.1016/s0039-6109(05)70381-9. PMID: 10352653.

Latremoliere A, Woolf CJ. Central sensitization: a generator of pain hypersensitivity by central neural plasticity. J Pain. 2009 Sep;10(9):895-926. doi: 10.1016/j.jpain.2009.06.012. PMID: 19712899; PMCID: PMC2750819.

Presenting Author

Georgiana Freire

Poster Authors

Georgiana Freire

MD

FMUSP

Lead Author

Felipe Chiodini MD phD

HC-FMUSP

Lead Author

Francisco de Oliveira MD

FMUSP

Lead Author

Bruno Costa MD

FMUSP

Lead Author

Paula Diniz MD

FMUSP

Lead Author

Giovane Nunes MD

FMUSP

Lead Author

Aquila Gouvea RN phD

HCFMUSP

Lead Author

Topics

  • Assessment and Diagnosis