Is the Latent Structure of Fear of Pain Continuous or Discontinuous Among Pain Patients? Taxometric Analysis of the Pain Anxiety Symptoms Scale

Elevated fear of pain is believed to denote a potential mechanism through which pain is maintained over time; however, our knowledge about fear of pain, its measurement, and its conceptualization is far from complete. It has been assumed that the latent structure of fear of pain is multidimensional and continuous. Although there is factor analytic evidence that it is multidimensional, there have been no empiric efforts to establish whether fear of pain is continuous or discontinuous (ie, taxonic or dichotomous latent class variable) in nature. Using taxometric methods in a sample of 650 patients seeking treatment for musculoskeletal or headache pain, we evaluated the latent structure of fear of pain as indexed by the Pain Anxiety Symptoms Scale. Results from analyses of simulated Monte Carlo data, MAXEIG-HITMAX, and MAMBAC and L-mode external consistency tests indicated that the latent structure of fear of pain was nontaxonic, characterized by latent continuity. Results are discussed in relation to the conceptual understanding of fear of pain, implications for treatment, and future directions for research on issues pertinent to pain-related fear. Perspective: This article presents an analysis designed to establish whether fear of pain is continuous or discontinuous in clinical samples. The findings, indicating that fear of pain is continuous, are important for understanding the nature of fear of pain and to designing appropriately targeted interventions.