Objectives: This study examined the pattern of use and factors predicting prolonged prescription opioid medications among cancer patients following treatment with curative intent.
Materials and methods: Patients diagnosed with cancer over a 3-year period at a large urban safety-net hospital were included. Univariate and multivariate analyses was used to identify factors associated with continued opioid use.
Results: Of the 199 patients included in the study, 38% continued to receive an opioid prescription well beyond the acute diagnosis and treatment phase. Mean age was 60.3 years, with a female preponderance (63%). Surgical resection only (31.6%) and the combination of surgery, chemotherapy, and radiation (19.7%) were the commonest treatment modalities. Pain-related comorbidities predating cancer diagnosis were reported in 53.3% of the patients, and about 33% were also on pain-modifying medications (odds ratio [OR], 3.58; 95% confidence interval [CI], 1.92-6.77; Fisher exact test P<0.001). Average number of prescriptions received per patient was 4.8 (range, 1 to 31), over an average of 9.5 months (range, 1.2 to 28.1 mo). Mean morphine milligram equivalents prescribed per prescription was 319 mg (range, 48 to 2475 mg). According to multivariate model, patients who received chemotherapy (OR, 7.25; 95% CI, 2.09-25.17; P=0.0018), or pain-modifying medications (OR, 4.61; 95% CI, 2.25-9.44; P<0.0001) were significantly more likely to continue to receive prescriptions for opioids.
Discussion: Treatment with chemotherapy, pain-modifying medications, cancer stage, and interval between diagnosis and treatment are the best predictors for continuous opioid use. The current epidemic of opioid misuse and abuse makes examination current practices and identifification of areas of improvement imperative.