Influence of comorbidities on pain intensity in patients with chronic low back pain.

Objectives: Chronic pain is a complex process that can vary depending on factors such as time evolution, mood, or even previous experiences. Our objective is to describe patient's characteristics from those who were referred with a diagnosis of low back pain in their first Pain Unit (PU) visit, and identify those factors that may interfere with their pain perception.

Methods: Inferential analysis was carried out from data recorded in the PU database of the Hospital de la Santa Creu y Sant Pau in Barcelona, from November 2012 to November 2018. The average pain intensity during the last 24 hours (EVN24) was quantified using data from the BPI (Brief Pain Inventory) questionnaire. Using multiple linear regression, the independent predictive factors related to pain intensity (EVN24) were assessed.

Results: Mood disorders (Degree of depresión acording HAD_D level) was the variable with the highest impact in pain perception. Using binary logistic regression for multivariate analysis, a model of variables related to pain intensity (EVN24) was obtained (R = 0.354, P < 0.001).

Conclusions: The specialized treatment of low back pain in PUs must take into account the patient's profile and especially the affective disorders and associated comorbidities since they predict a greater intensity of pain. Consequently, the associated comorbidity not only affects the greater intensity of pain, but the physical characteristics that accompany the patient throughout the process can influence or even compromise treatment.