A Longitudinal Study of Predictors of Constipation Severity in Oncology Outpatients With Unrelieved Pain

Although constipation is a common symptom in oncology patients, it often goes unrecognized and untreated. In addition, little is known about characteristics associated with interindividual differences in constipation severity.

To describe prevalence, characteristics, and management of constipation; evaluate interindividual differences in constipation severity over 10 weeks; and identify demographic, clinical, and symptom characteristics associated with higher constipation severity scores.

In this prospective, longitudinal study, 175 oncology patients with unrelieved pain were recruited from eight outpatient cancer settings in the U.S. Patients completed demographic and symptom questionnaires at enrollment. Constipation severity was evaluated over 10 weeks using the Constipation Assessment Scale (CAS). Hierarchical linear modeling was used to identify characteristics associated with higher CAS scores.

At enrollment, 70.1% of the patients reported constipation [i.e., CAS score of >2; mean CAS score: 3.72 (±3.11)]. While over the first week of the study patients used one to two constipation treatments per day, a large amount of interindividual variability was found in CAS scores. Higher percentage of days with no bowel movement, higher number of constipation treatments, higher state anxiety scores, and higher analgesic side effects scores were associated with higher CAS scores at enrollment. Higher percentage of days with no bowel movement was associated with interindividual differences in the trajectories of constipation.

Our findings underscore the high prevalence of and large amount of interindividual variability in constipation severity. The characteristics associated with worse CAS scores can assist clinicians to identify high-risk patients and initiate prompt interventions.