Good medication adherence improves outcomes in COPD patients
MedWire News: Chronic obstructive pulmonary disease (COPD) patients with good adherence to inhaled medications are less likely to die or be hospitalized because of exacerbations than their counterparts with poor adherence, research shows.
Writing in the journal Thorax, Jørgen Vestbo (University of Manchester, UK) and team explain: “Most of the medications used for maintenance treatment of COPD have an immediate symptomatic effect easily perceived by patients. For this reason, drug adherence in COPD is often assumed to be good and associated with disease severity, making patients with severe disease more likely to be adherent to therapy than patients with mild or moderate disease.
“Nevertheless, very little data are available to support these beliefs.”
To investigate the effects of medication adherence in COPD, the researchers assessed data on 6112 patients with moderate-to-severe disease who participated in the 3-year TORCH (Towards a Revolution in COPD Health) study. This was a randomized study comparing the effects of salmeterol, fluticasone propionate, a combination of the drugs, and placebo on overall mortality.
Good adherence was defined as an average adherence to study medications of more than 80.0% over the whole period, with poor adherence defined as an average adherence of 80.0% or less.
Overall, 79.8% of the participants had good adherence, with little difference in adherence between treatment groups. Of the 20.2% with poor adherence, 61.0% (12.3% of all patients) had less than 70.0% adherence and only 40.0% (8.0% of all patients) had less than 60.0% adherence.
Although there were only slight differences between patients with good and poor adherence at baseline, 26.4% of those with poor adherence died during the study period compared with just 11.3% of those with good adherence.
After accounting for age, gender, smoking status, FEV1, body mass index, dyspnea score, and other variables, good adherence was associated with a 60.0% reduced risk for dying during the 3-year study compared with poor adherence.
The team also found that, after adjustment, participants with good adherence were 42% less likely to be hospitalized due to exacerbations than those with poor adherence.
The benefits of increased adherence on mortality and hospitalization risk were independent of study treatment, the researchers note.
They conclude: “We found a surprisingly strong association between adherence and mortality as well as risk of hospital admission due to an exacerbation in this 3-year trial of inhaled medications in patients with moderate-severe COPD.
“A better understanding of the factors differentiating good and poor adherence to medication, and strategies to improve adherence, could lead to beneficial interventions in COPD.”
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By Mark Cowen