Opioid Misuse in Patients With Cancer

Prevalence of Opioid Misuse in Patients With Cancer

The success of opioid treatment in terminally ill cancer patients set the stage for extending the same treatment principles to the treatment of all chronic pain conditions including chronic non-cancer pain and chronic pain in cancer, where survival and long-standing chronic disease trajectories are getting more prevalent due to increasing survival rates. In this context, opioid misuse as such has been highly neglected - especially in palliative care, but also in cancer pain management in general. Previous studies have explored the literature on opioid misuse among adult cancer patients, noting that the available evidence is still in its early stages. Limited prospective studies with a wide range of definitions and methodologies for assessing misuse exist. Therefore, it seems highly relevant and justified to study the prevalence of opioid misuse risk in patients with cancer. The hypothesis of this study is that opioid misuse is not uncommon in Danish patients in treatment with opioids for cancer-related pain. Thus, the prevalence of opioid misuse risk among patients with cancer in Danish palliative care units will be investigate.

This is a prospective and cross-sectional study, in which opioid misuse is defined according to National Institute on Drug Abuse (USA) as the use of prescription opioids in a manner other than as directed by a doctor (e.g., for other purpose than pain relief, in greater amounts, more frequently, longer, using someone else's prescription). The aims are:

1. Investigate the prevalence of opioid misuse risk by the Pain Medication Questionnaire (PMQ) and the Opioid Risk Tool (ORT) among patients with cancer in palliative care units in Denmark.
2. Determine whether there is a correlation between the PMQ and ORT scores and opioid consumption, use of short-acting opioids (prn-dosing), tobacco smoking, alcohol consumption, previous consumption of illicit drugs and/or consumption of benzodiazepines and benzodiazepine-like hypnotics, and information provided by the physician regarding the patient's opioid misuse.
3. Investigate the association between opioid misuse risk (PMQ and ORT scores), depression and anxiety (Patient Health Questionnaire for Depression and Anxiety, PHQ-4), and health-related quality of life (EORTC-QLQ-C15-PAL).

Inclusion Criteria:

• Outpatients ≥ 18 years,
• patients who are treated with opioids due to cancer-related pain.

Exclusion Criteria:

• Patients who do not master the Danish language in speech and writing,
• Patients who have severe cognitive dysfunction,
• Patients who are not treated with opioids,
• Patients who refused to participate in the study.