One evidence base; three stories: do opioids relieve chronic breathlessness?

Area of Science:

• Palliative Care
• Respiratory Medicine
• Clinical Pharmacology

Background:

• A recent Cochrane review questioned the efficacy of low-dose systemic opioids for chronic breathlessness.
• This re-evaluation addresses limitations in the Cochrane review's methodology, specifically the handling of crossover trial data and risk-of-bias criteria.

Discussion:

• The Cochrane review by Barnes et al. reported smaller effect sizes and lower precision for opioid efficacy.
• This was partly due to not accounting for matched data in crossover trials and incorporating a sample size risk-of-bias criterion.

Key Insights:

• Re-analysis accounting for crossover data demonstrates that systemic opioids significantly decrease breathlessness.
• Opioids reduced breathlessness by a standardized mean difference of -0.32 (95% CI -0.18 to -0.47), a clinically meaningful reduction of 0.8 points on a 0-10 numerical rating scale.
• This finding is consistent across multiple meta-analyses, reinforcing the therapeutic benefit of opioids.

Outlook:

• Further research may focus on optimizing opioid therapy for chronic breathlessness.
• Understanding the nuances of trial data analysis is crucial for accurate efficacy assessments in palliative care.