Background. Subcategorising patients with chronic low back pain (CLBP) could improve patient outcomes and facilitate prioritisation of treatment resources. Objective. This study aimed to develop a subcategorising method for individuals with CLBP using the Coping Strategies Questionnaire 24 (CSQ24) and to investigate the methods potential validity. Methods. 196 patients were recruited from a physiotherapy outpatients department. All participants completed a battery of questionnaires before and after treatment including the CSQ24 and a measure of pain, disability, and mood. At discharge participants also completed a global subjective outcomes scale consisting of a 6-point Likert scale. All participants received usual physiotherapy. Results. Cut-off values for the CSQ24 were calculated using triangulation of the findings from three different statistical methods. Cut-off values were identified for the Catastrophising and Cognitive Coping subscales of the CSQ24. Participants were categorised into low, medium, and high risk of a poor outcome. The cut-off values for these were ≥21 on Cognitive Coping and ≤9 on Catastrophising for low risk and ≤15 on Cognitive Coping for high risk, with all other patients being classified as being at moderate risk. Conclusion. Further validation is required before this approach can be recommended for clinical practice.