# Trajectories and predictors of high-occurrence pain flares in ambulatory cancer patients on opioids

## TL;DR

This study finds that some cancer patients on opioids experience frequent pain flares, which are linked to social and clinical factors.

## Contribution

The study identifies distinct pain flare patterns and their predictors in ambulatory cancer patients using longitudinal data.

## Key findings

- 23% of patients experienced high-occurrence pain flares with 5.5 daily flares on average.
- High-occurrence flares were associated with opioid prescription type and social determinants like income and education.
- PRN-only opioid regimen was a significant predictor of high-occurrence pain flares.

## Abstract

Pain flares have a substantive impact on the quality of life and well-being of patients with cancer. We identified longitudinal trajectories (clusters) of cancer pain flares in ambulatory patients and sociodemographic and clinical predictors of these trajectories.

In a prospective cohort study using ecological momentary assessment (mEMA), we collected patient-reported daily pain flare ratings data over 5 months and identified predictors and correlates using validated measures.

The mean age of the sample (N = 270) was 60.9 years (SD = 11.2), 64.8% were female, and 32.6% self-identified as African American. Four pain flare clusters were identified. The “high-occurrence” cluster (23% of patients) experienced 5.5 (SD = 5.47) daily flares, whereas low-moderate clusters (77%) reported 2.4 (SD = 2.74) daily flares (P < .000). Those in the high-occurrence cluster reported higher pain scores (P = .000), increased pain-related interference (P = .000), depressive symptoms (P = .023), lower quality of life (P = .001), and reduced pain self-efficacy (P = .006). Notably, 67.2% of those prescribed opioids as needed (PRN only) were in the high-occurrence pain flare cluster, compared with 27.9% with PRN and around-the-clock opioid prescriptions (P = .024). Individual predictors of high-occurrence pain flares were income below $30 000, unemployment, being African American, lower education level, Medicaid insurance, current opioid misuse (COMM), baseline inpatient hospital stay duration, and PRN-only opioid regimen. In the multiple predictor model, lower education level, unemployment, COMM score, extended inpatient duration, and PRN-only opioid regimen remained significant.

In ambulatory patients with cancer, high occurrence of pain flares may be mitigated by attention to opioid prescription factors and addressing social determinants of health needs of underserved patients.