The development and validation of hundred paisa pain scale for measuring musculoskeletal pain: A prospective observational study

The reduction in the pain intensity is one of the most important outcome measures in musculoskeletal disorders. The assessment of pain required reliable and valid scale. The aims of this prospective observational study were to develop and evaluate concurrent validity and test-retest reliability of hundred paisa pain scale (HPPS) for measuring musculoskeletal pain. A consecutive 74 patients with musculoskeletal pain with a wide variety of diagnoses were enrolled. Patients reported their intensity of pain on the following scale: HPPS, ''visual analog scale (VAS),'' and ''numerical rating scale (NRS).'' Patients were asked to complete another HPPS, VAS, and NRS after 2 days to determine the reproducibility of the scales. Spearman rank correlation coefficients between the HPPS and the NRS, and VAS were used to determine the validity of the scales. The correlation between the change score of HPPS, VAS, and NRS was used to determine the responsiveness of HPPS. Results of test-retest indicate that the reproducibility of HPPS was good to excellent with the intraclass correlation coefficient (ICC) value of 0.85 (95% confidence interval [CI], 0.76-0.91). The standard error of measurement (SEM) was 5.24. The minimum detectable change based on the SEM for test-retest was 14.52. The reproducibility of VAS is moderate to good with the ICC value of 0.82 (95% CI, 0.72-0.88). The reproducibility of NRS is good to excellent with the ICC value of 0.88 (95% CI, 0.81-0.92). There was a strong correlation between the HPPS and the VAS, and NRS (P<0.01), which confirm the validity. The HPPS was responsive as the correlation of the change score of HPPS with the change score of VAS, and NRS were good (0.80 and 0.86, respectively). The HPPS is a valid and reliable scale to assess musculoskeletal pain, with psychometric properties in agreement with other comparable scale.