Quality of life and adherence to inhaled corticosteroids and tiotropium in COPD are related

Abstract

Background

Poor adherence to inhaled medications in COPD patients seems to be associated with an increased risk of death and hospitalization. Knowing the determinants of nonadherence to inhaled medications is important for creating interventions to improve adherence.

Objectives

To identify disease-specific and health-related quality of life (HRQoL) factors, associated with adherence to inhaled corticosteroids (ICS) and tiotropium in COPD patients.

Methods

Adherence of 795 patients was recorded over 3 years and was deemed optimal at >75%–≤125%, suboptimal at ≥50%–<75%, and poor at <50% (underuse) or >125% (overuse). Health-related quality of life was measured with the Clinical COPD Questionnaire and the EuroQol-5D questionnaire.

Results

Patients with a higher forced expiratory volume in 1 second (FEV₁)/vital capacity (VC) (odds ratio [OR] =1.03) and ≥1 hospitalizations in the year prior to inclusion in this study (OR =2.67) had an increased risk of suboptimal adherence to ICS instead of optimal adherence. An increased risk of underuse was predicted by a higher FEV₁/VC (OR =1.05). Predictors for the risk of overuse were a lower FEV₁ (OR =0.49), higher scores on Clinical COPD Questionnaire-question 3 (anxiety for dyspnea) (OR =1.26), and current smoking (OR =1.73). Regarding tiotropium, predictors for suboptimal use were a higher FEV₁/VC (OR =1.03) and the inability to perform usual activities as asked by the EuroQol-5D questionnaire (OR =3.09). A higher FEV₁/VC also was a predictor for the risk of underuse compared to optimal adherence (OR =1.03). The risk of overuse increased again with higher scores on Clinical COPD Questionnaire-question 3 (OR =1.46).

Conclusion

Several disease-specific and quality of life factors are related to ICS and tiotropium adherence, but a clear profile of a nonadherent patient cannot yet be outlined. Overusers of ICS and tiotropium experience more anxiety.

Keywords:

• chronic obstructive pulmonary disease
• adherence
• inhalation medication
• quality of life

Acknowledgments

This study was partly supported by an unrestricted research grant from GlaxoSmithKline.

Disclosure

The authors report no conflicts of interest in this work.