Pain intensity predicts complexity of cancer pain management

NEW YORK (Reuters Health) - Pain intensity at initial assessment is significantly predictive of pain management complexity and length of time to stable pain control in patients with cancer, according to researchers.

"The Edmonton Classification System for Cancer Pain (ECS-CP) has demonstrated value in predicting pain management complexity based on five features: pain mechanism, incident pain, psychological distress, addictive behavior, and cognitive function," Dr. Robin L. Fainsinger, of the University of Alberta, Edmonton, and colleagues write. "Pain intensity at initial assessment has been proposed as having additional predictive value.

The researchers examined whether pain intensity at initial assessment would predict the length of time to stable pain control in 591 patients with cancer pain, and whether baseline pain intensity is associated with more frequent and complex use of adjuvant modalities.

The team hypothesized that patients with moderate to severe cancer pain at initial assessment would take longer to achieve stable pain control, use higher opium doses, and need more complicated analgesic regimens than those with mild pain.

The authors performed a secondary analysis using the multicenter ECS-CP validation study that included 591 patients with advanced cancer. They calculated associations between pain intensity and length of time to stable pain control, final opioid dose, and number of adjuvant modalities (adjuvant analgesics and nonpharmacological treatments). Results of the study are published in the current issue of the Journal of Clinical Oncology.

Of the 591 patients included in the study, 304 (51%) had mild, 166 (28%) had moderate, and 121 (21%) had severe pain intensity at baseline.

Overall, pain control was achieved in 374 patients (63%). "Twenty percent of patients died and 17% were discharged before achieving stable pain control.

The median number of days to achieve stable pain control increased from 4 to 22 days as pain increased in severity," Dr. Fainsinger and colleagues explain. Patients with moderate and severe ratings at initial assessment required a longer time to achieve stable pain control than did patients with mild pain.

A multivariate analysis revealed four significant predictors of length of time to pain control: moderate pain (HR = 0.57; p < 0.0001), severe pain (HR = 0.34; p < 0.0001), age (HR = 1.52; p = 0.001), and neuropathic pain (HR = 0.60; p = 0.002).

Compared to patients with mild pain intensity, those with moderate to severe pain required significantly higher final opioid doses and more adjuvant modalities.

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