Correlative study of 3 pain rating scales among obstetric patients.

The relationship between pain scores obtained on the Visual Analog Scale (VAS) the Box Numerical Scale (BNS) and Verbal Rating Scale (VRS) was studied. The subjects were 35 volunteer female patients who had their babies through caesarian section 1-3 days prior to the study. Demographic data and pain scores were collected through a questionnaire, which was available in both English and Yoruba, the two most commonly spoken languages in Ibadan where the study was carried out. Data were analysed using Pearson Product, Moment Correlation Coefficient, and One-way Analysis of Variance. Results indicated that there was no significant difference between the pain scores obtained on the 3 pain rating scales. Significant correlations existed between pain scores obtained on the VAS and VRS (r = 0.48, p = 0.003); VAS and BNS (r = 0.74, P = 0.000); BNS and VRS (r = 0.74, P = 0.000). High educational attainment improved correlation between the scales in this study. It was concluded that the three pain rating scales measure the same construct, and could be used for pain measurement in obstetrically related conditions in this environment.