Pain catastrophizing levels differentiate between common diseases with pain: HIV, fibromyalgia, complex regional pain syndrome, and breast cancer survivors.

Objectives: Pain catastrophizing is a core psychological factor determining pain experience. We addressed the question of whether patients with different pain syndromes group into different pain catastrophizing phenotypes.

Methods: A total of 727 patients with chronic pain associated with four primary syndromes: Breast cancer (BC) survivors (n = 400), fibromyalgia (FM, n = 52), complex regional pain syndrome (CRPS, n = 155), and HIV (n = 120) were first studied for differences in levels of pain catastrophizing (Pain Catastrophizing Scale, PCS) and pain intensity by analysis of variance. Subsequently, individual scores of the PCS subscales "rumination", "magnification," and "helplessness" from the pooled cohorts were submitted to multivariate k-means clustering to explore subgroups.

Results: Three clusters defined by the level of catastrophizing were identified. The "low catastrophizing" cluster (n = 377) included most of the BC patients (71.0%) and the "moderate catastrophizing" cluster (n = 256) most of the FM patients (61.5%). HIV (31.9%) and CRPS (44.7%) patients were over-represented in the "high catastrophizing" cluster (n = 94) with the highest catastrophizing tendencies in all dimensions. These patients reported more helplessness than the patients in the two other clusters.

Conclusions: The primary syndrome causing the pain has an impact on self-reported pain-related catastrophizing. Helplessness is a predominant feature in HIV and CRPS patients and therefore an important target in pain rehabilitation.