To improve the prevention and treatment chronic pain problem, it is necessary to understand the psychological processes that govern it. In this study, four different groups were formed efficiently according to pre-treatment scores on the different questionnaires which were juxtaposed on vulnerability factors and outcome factors.

Chronic pain problems are related to specific pain related fears and maladaptive pain-coping but also commonly co-occur with other anxiety problems. Shared emotional vulnerability factors may explain this comorbidity and may influence treatment outcome. Indeed, pain patients going through multimodal pain treatment are a heterogeneous group and treatment results vary. One understudied anxiety disorder co-occurring with pain is social anxiety. This may be relevant as many pain-related challenges are situated in social contexts. The aim of this study is to investigate the occurrence of subgroups with differential patterns of social anxiety and pain related fear in a sample of chronic pain patients who receive multimodal pain treatment. The aim is also to study the characteristics of these potential subgroups and the consequences of different patterns of social anxiety and pain related fear.

Total 180 patients with chronic musculoskeletal pain answered questionnaires before and after a multimodal pain treatment in a hospital rehabilitation setting in middle Sweden. A cluster analysis using pre-treatment scores on the Social Phobia Screening Questionnaire and the Tampa Scale of Kinesiophobia was performed. Subgroups were thereafter validated and compared on impairment due to social anxiety, pain catastrophizing, anxiety, and depression. Moreover, subgroups were described and compared on vulnerability factors (anxiety sensitivity, negative affect) and outcome factors (pain intensity, pain interference, and return to work self-efficacy).

Four distinct clusters emerged: (1) low scores, (2) pain-related fear only, (3) social concern only, and (4) high social anxiety and pain-related fear. Patients high on social anxiety and pain-related fear had significantly higher levels of anxiety sensitivity, negative affect, and higher general emotional symptomatology. They also had remaining problems post treatment.

A subgroup of patients with clinical levels of social anxiety has suboptimal rehabilitation results, with residual emotional problems and high levels of emotional vulnerability. These patients may be in need of additional treatment efforts that are not being met today. To prevent insufficient treatment results and prolonged work disability, these patients need to be detected during screening and may benefit from pain treatment that takes their emotional problems into account.