The Need for Multidimensional Stratification of Chronic Low Back Pain (LBP)

Study Design. A cross-sectional study of Canadian patients suffering from low back pain (LBP) seeking primary care. Objective. The aim of this study was to determine which existing primary care LBP stratification schema is associated with distinct subpopulations as characterized by easily identifiable primary epidemiological factors. Summary of Background Data. LBP is among the most frequent reasons for visits to primary care physicians and a leading cause of years lived with disability. In an effort to improve treatment response/outcomes in LBP primary care, different classification systems have been proposed in an effort to provide more tailored treatment with the intent of improving outcomes. Group-specific risk factors and underlying etiology might suggest a need for, or inform, changes to treatment approaches to optimize LBP outcomes. Methods. Stratification by dominant mechanical pain patterns; chronicity risk; disability severity. Multinomial logistic regression was used to identify the system showing greatest variability in associations with age, sex, obesity, and comorbidity. Once identified, the remaining schemas were incorporated into the model. Results. N = 970; mean age: 50 years (range: 18-93); 56% female. Stratification by pain pattern revealed greater variability. Adjusted analysis: Increasing age was associated with greater odds of intermittent, extension-based back-or leg-dominant pain [odds ratio (OR): 1.02 and 1.06; P < 0.01]; being male with legdominant pain (ORs > 2; P < 0.01). Overweight/obesity was associated with extension-based leg-dominant pain (OR = 2.6; P < 0.02) and increasing comorbidity with extension-based back-dominant pain (OR = 1.3; P < 0.01). Severe disability was associated only with constant leg pain (OR = 3.9; P < 0.01), and high chronicity risk with extension-based leg-dominant pain (OR = 0.4; P = 0.03). Conclusion. Dominant mechanical symptom stratification resulted in further discrimination of an epidemiologically distinct and a large subgroup of LBP patients not identified by disability or chronicity risk stratification alone. Findings suggest a need for primary care initiated multidimensional stratification in chronic LBP.