Inconsistent Adherence Increases Hospitalization in Cancer Patients

Previous studies have found that prescription opiod use increases adverse events and acute health care utilization for individuals experiencing noncancer chronic pain.

Given the preeminence of analgesics, including opiods, in the management of cancer pain, researchers sought to determine if analgesia adherence, or any other risk factors, could predict hospitalization rates in cancer pain populations.

Their inquiry was based on a 3-month prospective observational study of outpatients experiencing cancer pain, previously performed to understand preferences and adherence rates for around-the-clock (ATC) analgesia. An unintended finding of that study was that ATC analgesia adherence patterns seemed to predict hospitalization rates during the 3-month period.

One of the original study authors worked with a partner to conduct a secondary analysis of the data from patients (1) diagnosed with multiple myeloma or solid tumors; (2) experiencing cancer-related pain; and (3) having been prescribed oral ATC analgesics. The study recruited 196 participants from December 2009 to August 2011 from 2 outpatient oncology clinics in Philadelphia, PA.

The study collected adherence data using a medication event-monitoring system (MEMS). MEMS uses pill bottles embedded with a microprocessor to record each time the cap is removed.

The purpose of this secondary analysis, using adaptive modeling methods, was to identify analgesia adherence patterns and other risk factors, and to examine how they may interact to predict hospitalization rates among outpatients with cancer pain.

Detailed methodology and findings are published in Patient Preference and Adherence, January 2016.

Six adherence pattern types were identified and combined into 1 risk factor for hospitalization (inconsistent analgesic adherence). Twenty other risk factors for hospitalization were identified.

All told, investigators found that inconsistent analgesic adherence was the strongest predictor of hospitalization. Other risk factors found to predict hospitalization in combination were: (1) younger age; (2) lower health literacy; (3) strong ATC opiod use; and (4) fear that pain medicine can harm your immune system.

The combined risk of inconsistent adherence and strong (WHO step 3) ATC opiod use was the most important interaction observed by this study.

For outpatients who experience cancer pain, inconsistent adherence to prescribed ATC analgesic medications, especially strong step 3 ATC opiods, is a main predictor of increased hospitalization.