Establishing the Reliability, Validity, and Prognostic Utility of the Momentary Pain Catastrophizing Scale for use in Ecological Momentary Assessment Research

Despite the marked increase in Ecological Momentary Assessment (EMA) research, few reliable and valid measures of momentary experiences have been established. The goal of this preregistered study was to establish the reliability, validity, and prognostic utility of the momentary Pain Catastrophizing Scale (mPCS), a 3-item measure developed to assess situational pain catastrophizing. Participants in two studies of postsurgical pain outcomes completed the mPCS three to five times per day prior to surgery (N = 494, T = 20,271 total assessments). The mPCS showed good psychometric properties, including multilevel reliability and factor invariance across time. Participant-level average mPCS was strongly positively correlated with dispositional pain catastrophizing as assessed by the Pain Catastrophizing Scale (r = .55 and .69 in Study 1 and Study 2, respectively). To establish prognostic utility, we then examined whether the mPCS improved prediction of postsurgical pain outcomes above and beyond one-time assessment of dispositional pain catastrophizing. Indeed, greater variability in momentary pain catastrophizing prior to surgery was uniquely associated with increased pain immediately after surgery (b = 0.58, p = 0.005), after controlling for preoperative pain levels and dispositional pain catastrophizing. Greater average mPCS score prior to surgery was also uniquely associated with lesser day-to-day improvement in postsurgical pain (b = 0.01, p = 0.003), whereas dispositional pain catastrophizing was not (b = -0.007, p = 0.099). These results show that the mPCS is a reliable and valid tool for EMA research and highlight its potential utility over and above retrospective measures of pain catastrophizing.