Exploratory Biopsychosocial Profiles in Adults with Chronic Low Back Pain: A Cluster Analysis of Clinical, Psychological, Sleep, and Physical Characteristics

Background and Objectives: Chronic low back pain (CLBP) is a heterogeneous condition shaped by interacting clinical, psychological, sleep-related, physical, and contextual factors. This study aimed to identify exploratory biopsychosocial profiles in adults with CLBP and to examine whether sociodemographic and anthropometric characteristics differed across the identified profiles. Methods: This cross-sectional study included 143 adults with CLBP recruited from healthcare services in northern Ecuador. Nine clinical, psychological, sleep-related, and physical variables were standardized and entered into a cluster analysis. Sociodemographic and anthropometric variables not used to derive the clusters were subsequently examined as external characteristics. Results: Two profiles were identified (Cluster 1, n = 54; Cluster 2, n = 89), with limited internal separation (mean silhouette coefficient = 0.163). The greatest between-profile contrasts were observed for neuropathic-like pain characteristics, pain catastrophizing, and fear-avoidance beliefs, whereas disability and sleep quality contributed comparatively less to profile differentiation. A PD-Q score ≥19 was observed in 9.3% of participants in Cluster 1 and 40.4% in Cluster 2. Cluster membership was significantly associated with educational level (p = 0.006) and place of residence (p < 0.001), whereas no statistically significant association was observed for sex (p = 0.061). Conclusions: These findings provide evidence of multidimensional heterogeneity among adults with CLBP. Difference between profiles appeared to be driven predominantly by neuropathic-like and cognitive–emotional characteristics rather than by pain intensity or disability alone. The limited internal separation suggests that the identified profiles may represent partially overlapping patterns within a broader biopsychosocial continuum rather than discrete clinical subtypes. Independent replication and external validation are required before these profiles can be considered for clinical stratification or treatment decision-making.