Correlation between numerical rating scale (NRS) and visual analogue scale (VAS) in assessment of pain in post operative patients
Abstract
38 consecutive consenting patients undergoing donor nephrectomy via loin incision were studied and assessed for the severity of pain by using both NRS and VAS at the beginning of commencing post-operative analgesia and then 2, 6, 12 and 24 hour intervals respectively. Data were analyzed to identify the correlation between the scales.
157 readings for NRS and VAS were analyzed which showed Beta coefficient of 0.87 (p < 0.01) in linear regression. Pearson correlation for the association was 0.904(p < 0.01). Pearson correlation for the NRS and VAS values taken at 2 and 6 hour intervals were higher than the overall Pearson correlation (0.904), while the values taken at other intervals were lower.
NRS which is less pain inducing in post-operative period has a strong linear association with VAS, thus can substitute for VAS in assessment of post-operative pain. The reliability of NRS is higher at the commencement of analgesia, at 2 and 6 hour intervals.
Key Words: Visual Analogue Scale; Numerical Rating Scale; post-operative pain
DOI: 10.4038/slja.v18i2.2445
Sri Lankan Journal of Anaesthesiology 18(2): 81-83 (2010)
© 2010 Seneth Gajasinghe, Mandika Wijayaratna, Anuja Abayadeera, published by College of Anaesthesiologists of Sri Lanka
This work is licensed under the Creative Commons License.