No abstract

ObjectiveTo subgroup chronic pain patients using psychometric data and regress the variables most responsible for subgroup discrimination.DesignCross-sectional, registry-based study.Setting and subjectsChronic pain patients assessed at a multidisciplinary pain centre between 2008 and 2015.MethodsData from the Swedish quality registry for pain rehabilitation (SQRP) were retrieved and analysed by principal component analysis, hierarchical clustering analysis, and partial least squares–discriminant analysis.ResultsFour subgroups were identified. Group 1 was characterized by low “psychological strain”, the best relative situation concerning pain characteristics (intensity and spreading), the lowest frequency of fibromyalgia, as well as by a slightly older age. Group 2 was characterized by high “psychological strain” and by the most negative situation with respect to pain characteristics (intensity and spreading). Group 3 was characterized by high “social distress”, the longest pain durations, and a statistically higher frequency of females. The frequency of three neuropathic pain conditions was generally lower in this group. Group 4 was characterized by high psychological strain, low “social distress”, and high pain intensity.ConclusionsThe identification of these four clusters of chronic pain patients could be useful for the development of personalized rehabilitation programs. For example, the identification of a subgroup characterized mainly by high perceived “social distress” raises the question of how to best design interventions for such patients. Differentiating between clinically important subgroups and comparing how these subgroups respond to interventions is arguably an important area for further research.

Background Throughout the world many people have both obesity and chronic pain, comorbidities that decrease Health‐Related Quality of Life (HRQoL). It is uncertain whether patients with comorbid obesity can maintain improved HRQoL after Interdisciplinary Multimodal Pain Rehabilitation (IMMPR). Methods Data from 2016, 2017, and 2018 were obtained from a national pain database for Swedish specialized pain clinics and collected at three time points: Pre‐IMMPR; Post‐ IMMPR; and 12‐month follow‐up (FU‐IMMPR). Participants (N = 872) reported body weight, height, pain aspects, and HRQoL (RAND 36‐Item Health Survey). Severe obesity (Body Mass Index, BMI ≥35 kg/m2) was defined according to WHO classifications. We used linear mixed regression models to examine BMI group differences in HRQoL over time. Results More than 25% of patients (224/872) were obese and nearly 30% (63/224) of these were severely obese. All BMI groups improved significantly in both physical and mental composites of HRQoL after IMMPR (Pre‐ vs. Post‐IMMPR, p < .001). The improvements were maintained at a 12‐month follow‐up (Post‐ vs. FU‐IMMPR, p > .05). The severe obesity group had the lowest physical health score and least improvement (pre‐ vs. FU‐IMMPR, Cohen's d = o.422, small effect size). Severe obesity had negative impact on physical health (β = −4.39, p < .05) after controlling for sociodemographic factors and pain aspects. Conclusion Improvements in HRQoL after IMMPR were achieved and maintained across all weights, including patients with comorbid obesity. Only severe obesity was negatively associated with physical health aspects of HRQoL. Significance Patients with chronic pain and comorbid obesity achieve sustained Health‐Related Quality of Life (HRQoL) improvements from Interdisciplinary Multimodal Pain Rehabilitation (IMMPR). This finding suggests that rehabilitation professionals should consider using IMMPR for patients with comorbid obesity even though their improvement may not reach the same level as for non‐obese patients.