Type of pain, pain-associated complications, quality of life, disability and resource utilisation in chronic pancreatitis: a prospective cohort study

Abstract

Objective: To compare patients with chronic pancreatitis (CP) with constant pain patterns to patients with CP with intermittent pain patterns.

Methods: This was a prospective cohort study conducted at 20 tertiary medical centers in the USA comprising 540 subjects with CP. Patients with CP were asked to identify their pain from five pain patterns (A-E) defined by the temporal nature (intermittent or constant) and the severity of the pain (mild, moderate or severe). Pain pattern types were compared with respect to a variety of demographic, quality of life (QOL) and clinical parameters. Rates of disability were the primary outcome. Secondary outcomes included: use of pain medications, days lost from school or work, hospitalisations (preceding year and lifetime) and QOL as measured using the Short Form-12 (SF-12) questionnaire.

Results: Of the 540 CP patients, 414 patients (77%) self-identified with a particular pain pattern and were analysed. Patients with constant pain, regardless of severity, had higher rates of disability, hospitalisation and pain medication use than patients with intermittent pain. Patients with constant pain had lower QOL (by SF-12) compared with patients who had intermittent pain. Additionally, patients with constant pain were more likely to have alcohol as the aetiology for their pancreatitis. There was no association between the duration of the disease and the quality or severity of the pain.

Conclusions: This is the largest study ever conducted of pain in CP. These findings suggest that the temporal nature of pain is a more important determinant of health-related QOL and healthcare utilisation than pain severity. In contrast to previous studies, the pain associated with CP was not found to change in quality over time. These results have important implications for improving our understanding of the mechanisms underlying pain in CP and for the goals of future treatments and interventions.

Figure 1

Days lost per month from work or school by temporal classification (intermittent vs chronic) (A) and by severity (mild to moderate vs severe) (B).

Figure 2

Hospitalisations in the last year by temporal classification (intermittent vs chronic) (A) and by severity (mild to moderate vs severe) (B).

Figure 3

Hospitalisations over the entire lifetime by temporal classification (intermittent vs chronic) (A) and by severity (mild to moderate vs severe) (B).

Figure 4

Short Form-12 (SF-12) composite score (physical functioning (PCS) and mental functioning (MCS)) by individual pain pattern (A), by temporal pattern (B) and by pain severity (C). Higher scores are associated with greater well-being and better functioning.