Frequency, Predictors, and Medical Record Documentation of Chemical Coping Among Advanced Cancer Patients

Background: In this prospective study, we determined the frequency of opioid-related chemical coping among advanced cancer patients, as diagnosed by palliative medicine specialists. We also determined predictors for chemical coping and the concordance between the physician's diagnosis and documentation in the medical records.

Patients and methods: Palliative medicine specialists evaluated and diagnosed consecutive patients seen for chemical coping. The proportion of patients identified as chemically coping was compared with the proportion documented in the medical records. Demographic data; cancer diagnosis; history of smoking; substance abuse; psychiatric disease; morphine equivalent daily dosage; Cut-down, Annoyed, Guilty, and Eye-opener (CAGE) questionnaire scores; and Edmonton Symptom Assessment System scores were also collected.

Results: A total of 432 patients were evaluated. Overall, 76 patients (18%; 95% confidence interval [CI]: 14%-21%) were diagnosed as chemically coping. Documentation of chemical coping in the medical records was reported for only 15 patients (4%; 95% CI: 2%-6%). CAGE positivity (odds ratio [OR]: 2.89), younger age (OR: 0.97 per year), better performance status (OR: 0.68 per point), pain (OR: 1.20 per point), and well-being (OR: 1.28 per point) were found to be significant predictors of chemical coping by protocol definition. After recursive partitioning, 21 of 50 patients (42%) who were CAGE positive and had an Eastern Cooperative Oncology Group performance status ≤2 were diagnosed as chemically coping.

Conclusion: Approximately 18% of palliative care patients seen were diagnosed as chemically coping by palliative medicine specialists. The frequency of documentation in the medical records was significantly lower. Better and safer ways for physicians to assess and report chemical coping are needed.

Implications for practice: Cancer pain is a multidimensional symptom for which opioids are the mainstay of treatment. However, opioids can have a double effect resulting in drug-seeking behaviors. Chemical coping occurs when a patient uses opioids in a nonprescribed way to cope with various stressful events. This can lead to misuse of opioids and complications including neurotoxicities, respiratory depression, and death. Proper diagnosis and documentation is needed to ensure proper management of pain and to avoid unnecessary harm. The findings of this study suggest that ∼18% of advanced cancer patients seen by a palliative care service were diagnosed as chemical coping, but only 4% were documented in the medical records.