Development and Initial Validation of the Pain Progress Measure

Abstract

Introduction. Current numerical rating scales for pain mostly measure symptom intensity. There is a need to develop outcome measures reflecting the multifaceted nature of pain. The purpose of this study is to describe the development and validation of the Pain Progress Measure (PPM), which is an outcome measure intended to capture the holistic nature of pain. Methods. The author developed 15 pain assessment items related to the biopsychosocial theory of pain. For content validity, 14 expert panelists were purposely selected to assess items as either essential, or useful but not essential, and not essential. The number of essential items was then taken to get the content validity ratio (CVR). Internal consistency reliability was established through Cronbach's alpha. Results. The mean content validity ratio (CVR= 0.69) was above the critical value of 0.57 and therefore showed that the PPM has good content validity. There were 10 items shown with good CVR, but 5 items did not reach the critical values. Cronbach's alpha shows a coefficient of 0.883, demonstrating good reliability. Pearson-R correlation of 0.94 demonstrates excellent inter-rater reliability. Discussion. Pain Progress Measure (PPM) items below CVR critical value were removed to create the shortened version of the PPM. The shortened version without items below CVR critical value showed a higher mean CVR. Initial validation and reliability testing of the Pain Progress Measure has shown its capabilities to holistically quantify the pain of patients undergoing physical rehabilitation interventions. However, further research is recommended to expand on other psychometric properties such as concurrent validity, confirmatory factor analysis, and test-retest reliability.