Study Aims to Observe Effects of Inhalation Technique, Medication Adherence Among Patients With COPD

Investigators anticipate the results will help physicians tailor treatment methods for patients with chronic obstructive pulmonary disease (COPD) and help to better understand the demographic and clinical implications on peak inspiratory flow.

A multinational, observational study will determine the impact of peak inspiratory flow (PIF), inhalation technique, and medication adherence on patient-reported outcomes in patients with chronic obstructive pulmonary disease (COPD) using a dry powder inhaler (DPI) for their maintenance therapy, according to the study protocol published in Pulmonary Therapy.

Patients with respiratory diseases who use DPIs as a means of maintenance therapy must generate sufficient peak PIF to optimize drug delivery to the airways. The effectiveness of DPIs is also determined by the quality of inhalation technique and appropriate medication adherence. Recent studies have shown that compared with those with optimal PIF, patients with COPD who use DIPs with suboptimal PIF have poorer COPD-related health status and face higher exacerbation risks.

Investigators of the PIFotal study hope that the results will yield a better understanding of the relationships among PIF, inhalation technique, and medication adherence and their impact on the health of patients with COPD. The results will help physicians optimize effects of maintenance therapy by matching patients with COPD with the most suitable inhaler devices, as more than 20 different DPIs are currently available on the market.

The cross-sectional PIFotal study will assess 1200 patients across the Netherlands, Spain, Portugal, Poland, Greece, and Australia who are 40 years or older, have been diagnosed with COPD, and have used a DPI for 3 months or longer. Investigators will glean information from PIF measurements, Clinical COPD Questionnaire (CCQ) results, COPD Assessment Test and Test of Adherence to Inhalers scores, and video recordings of patient inhalation technique. 

The mean difference in CCQ score between patients with optimal and suboptimal PIF, exhibiting and not exhibiting inhalation technique errors, and adhering and not adhering to medication will be assessed in a multivariable linear mixed model.

Suboptimal PIF is the most common inhalation technique error for DPI users, but inhalation errors made when using other inhalers are also common. A previous meta-analysis of 10 studies indicated that the 3 most common inhalation technique errors associated with pressurized metered-dose inhalers (pMDIs) in 1105 patients with COPD were failure to exhale fully and away from the inhaler before inhalation, failure to hold breath for 5 to 10 seconds, and failure to inhale slowly and deeply.

Self-reported medication adherence will be measured on account of whether nonadherence is conscious, unwitting, or erratic. Nonadherence to medication can be conscious in the way the patient may doubt the effectiveness of treatment, unwitting in the way a patient may make an inhalation error that decreases medication effectiveness, or erratic in the way a patient may forget to take their medication.

Previous studies assessing the effect of PIF on patients with COPD have found that suboptimal PIF is a predictor for both all-cause and COPD-related hospital admission. Patients hospitalized with a COPD exacerbation who measured reduced PIF prior to discharge had significantly fewer days until their next all-cause and COPD readmission than patients who measured normal PIF.

While prevalence data on suboptimal PIF among patients with COPD are limited, patient effort, female gender, shorter height and older age have been identified as independent predictors for the reduced condition. The study hopes to further supplement data on the relationship between demographic and clinical characteristics and PIF.

Developing a comprehensive understanding of the relationships among PIF, inhalation technique, and medication adherence, as well as their impact on health status in patients with COPD, can lead to improvements in the effectiveness of maintenance therapy, strength of long-term disease control, and quality of life among patients, the authors noted.


Leving M, Wouters H, de la Hoz A, et al. Impact of PIF, inhalation technique and medication adherence on health status and exacerbations in COPD: protocol of a real-world observational study (PIFotal COPD study). Pulm Ther. 2021;7:591-606. doi:10.1007/s41030-021-00172-7