Frequency and predictors of patient deviation from prescribed opioids and barriers to opioid pain management in patients with advanced cancer.

Context: Approximately 80% of patients with advanced cancer report pain and receive opioids. Information is limited about deviations from prescribed opioid doses and barriers to pain control, but poor opioid adherence has been reported in 49%-70% of patients.

Objectives: To evaluate the frequency and severity of self-reported opioid deviation and barriers to opioid pain management in outpatients with advanced cancer.

Methods: We surveyed 198 patients and collected pain scores (0-10), prescribed opioid dose, confidential patient-reported opioid prescription dose and intake (as long as there was no severe opioid deviation), barriers to pain management (Barriers Questionnaire-II [BQ-II]) scores, and adherence scores. Opioid deviation was defined as <70% or >130% of the prescribed dose.

Results: Median patient age was 55 years; 91 (46%) were female. Median pain intensity and morphine equivalent daily dose were 4 (interquartile range=3-7) and 120mg (interquartile range=45-270mg), respectively. Prescribed and patient-reported prescribed doses were highly correlated for regular (r=0.90, P<0.001) and regular plus breakthrough opioid intake (r=0.94, P<0.001). Nineteen (9.6%) patients deviated. Deviation was more frequent in males (P=0.039) and nonwhites (P=0.0270). Nonwhite patients had higher scores on the BQ-II than white patients (P=0.038). Low adherence scores were significantly associated with higher BQ-II scores (1.99±0.80) for lower motivation score vs. 1.61±0.77 for higher score, P=0.007; and 2.13±0.79 for lower knowledge score vs. 1.57±0.72 for higher score, P=0.001.

Conclusion: Very few patients reported dose deviations, which were mostly toward lower dose. More research is necessary to better characterize the frequency and predictors of opioid deviation in this population.