Impact of constipation on opioid use patterns, health care resource utilization, and costs in cancer patients on opioid therapy
Patterns of opioid use, resource utilization, and costs in cancer patients with and without constipation were compared using retrospective insurance claims data. Inclusion criteria were > =30 days of opioid use and continuous plan coverage for > or =6 months before and > or =12 months following first opioid claim (index date). Constipation was defined as > or =1 ICD-9-CM diagnosis codes in the range of 564.0x during the 12 months postindex date. Of the 8836 opioid initiators with cancer initially considered, approximately 9.3% (n = 821) had a diagnosis of constipation during follow-up. Opioid use patterns were compared between patients with constipation and matched controls. Two-part semilogarithmic regression models assessed the impact of constipation on resource utilization and associated costs. Compared with controls without constipation, patients with constipation had higher rates of concurrent use of > or =2 opioids (P < .0001), opioid discontinuation (P = .0002), opioid switching (P < .0001), nausea with vomiting (P < .0001), and respiratory depression (P = .0003). Compared with controls, more patients with constipation received inpatient (P < .0001), hospice (P = .0086), home health (P < .0001), laboratory (P = .0015), other outpatient (P < .0001), emergency (P < .0001), office visit (P < .0001), and nursing home care (P = .0266). Compared with controls, patients with constipation had substantially higher total costs (P < .0001). This study suggests that in opioid-treated cancer patients, constipation significantly impacts opioid-use patterns, resource utilization, and costs. Alleviation of constipation may optimize opioid therapy and reduce costs.