Correlation between the Likert Scale and the Numeric Rating Scale for Evaluating Knee Pain

ABSTRACT

PURPOSE: The Likert scale and the numeric rating scale (NRS) have been widely used to evaluate knee pain. The purpose of the present study is to compare the Likert scale and the NRS. MATERIALS AND METHODS: The records of 350 patients who had painful knees were investigated from June 2008 to June 2009. The patients were divided into three groups. Group 1 included 98 patients who were admitted for total knee replacement, while group 2 consisted of 141 patients who underwent total knee replacement within a minimum of 1 year (range 1 to 5 year), and group 3 included 111 patients who were treated with conservative methods. We simultaneously evaluated the Likert scale and the NRS and we analyzed the relationships between them using Pearson's correlation test. RESULTS: The correlation coefficients between the Likert scale and the NRS was -0.91. The correlation coefficients for each group was -0.75 (group 1), -0.78 (group 2), and -0.68 (group 3), respectively. CONCLUSION: The Likert scale was correlated with the NRS and there were no significant differences between these two scales for evaluating knee pain. It is believed that the Likert scale is another useful tool for expressing knee pain.