Abstract
The aim of this study was to investigate opioid-induced constipation (OIC) in a large cohort of "real-world" patients with cancer; the objectives were to determine the prevalence of OIC, the utility of a simple screening question, the accuracy of the Rome IV diagnostic criteria, the clinical features of OIC (physical and psychological), and the impact of OIC (quality of life). One thousand patients with cancer were enrolled in the study, which involved completion of the Rome IV diagnostic criteria for OIC, the Bowel Function Index, the Patient Assessment of Constipation Quality of Life questionnaire, and the Memorial Symptom Assessment Scale-Short Form. Participants also underwent a thorough clinical assessment by an experienced clinician (ie, "gold-standard" assessment of OIC). Fifty-nine percent of patients were clinically assessed as having OIC, 2.5% as having another cause of constipation, and 19% as not having constipation but were taking regular laxatives. The simple screening question produced a number of false-negative results (19% of patients), whereas the Rome IV diagnostic criteria had an accuracy of 81.9%. Patients with OIC had more symptoms overall, higher Memorial Symptom Assessment Scale-Short Form subscale scores (and total score), and higher Patient Assessment of Constipation Quality of Life questionnaire subscale scores (and the overall score). Opioid-induced constipation was not associated with demographic factors, cancer diagnosis, performance status, or opioid equivalent dosage: OIC was associated with opioid analgesic, with patients receiving tramadol and transdermal buprenorphine having less constipation. The study confirms that OIC is common among patients with cancer pain and is associated with a spectrum of physical symptoms, a range of psychological symptoms, and an overall deterioration in the quality of life.