Objective: Although pain intensity is difficult to assess and quantify, different assessment tools have been developed for this purpose. The most widely used are verbal and numerical pain rating scales. This study aimed to establish the reliability in the Zimbabwean setting of four standardised scales.
Design: The study used a prospective, descriptive cross sectional design.
Subjects: The subjects were 40 females inpatients of the two government maternity units in Harare who had undergone caesarian section, one to three days prior to participation.
Main outcome measures: Each subject responded twice to four scales, the Visual Analogue, the Box Numerical, the Hewer and the McGill verbal descriptive scales with a one hour interval between each response.
Results: The Spearman's rank correlation showed significant positive correlations between each pain rating scale for the whole sample for the first responses. There were non significant correlations between the first and second responses for each scale for those with seven years or less years of education. There were positive significant correlations between first and second responses on each scale for those with more than seven years of education.
Conclusions: Both the numerical and verbal scales measure the same construct of pain experience. The scales are reliable when used with the more educated of the Zimbabwean population. It is recommended that the scales should not be used on a population who have less than seven years of education. More research is needed to determine the validity of pain scales within the Zimbabwean context.