Study Finds High Rate of Errors in Inhaler Technique and Treatment Nonadherence for COPD

Published on: 

A study on patients who use inhalers found that interventions to improve inhaler techniques and drug adherence are needed.

A small study of hospitalized patients with chronic obstructive pulmonary disease (COPD) and asthma in Sweden found that more than a quarter of them do not use their inhalers properly and struggle with treatment adherence.

All inhalers, whether they are metered dose inhalers (MDIs) or dry powder inhalers (DPIs), require multiple steps in order for the user to adequately receive the right dose of medication. If steps are performed incorrectly or if important ones are overlooked, some or all of the drug may not reach the lungs. Incorrect technique can lead to a poorer prognosis for patients with COPD and asthma, a higher risk of hospitalization, and can increase the costs of disease management.

Additionally, previous research has found that a higher risk of morbidity and mortality are associated with nonadherence to inhaled medications for people with COPD.

For the study, researchers invited 38 patients who were admitted to the orthopedic, geriatric, and medical wards at the Umeå University Hospital in October, November, and December 2018 and prescribed inhaled medications prior to admission. After some patients declined to participate and some were excluded, 23 were included in the final analysis. The majority were women with a mean age of 65 and the average number of medications they were taking was 7.2.

Participants who accepted the invitation were observed by the hospital pharmacist using a placebo inhaler to determine poor inhaler technique as assessed by a checklist for each inhaler and by a definition of critical errors.

Overall nonadherence to medication was determined using the Medication Adherence Report Scale (MARS)-5, a validated scale where participants rate how much they agree with 5 general statements about their adherence (forgetting the dose, altering the dose, stopping the dose, deciding to miss a dose, or taking less than instructed).

The results, published in Drugs Real World Outcomes, showed that 26.1% (6) of the 23 patients had 1 or more critical errors when using an inhaler and 30.4% (7) reported themselves as having issues being adherent with drug medication.

Out of 34 observations (29 DPIs and 5 MDIs) in 23 participants, 14 critical errors in technique were seen, and 6 (26.1%) participants had 1 or more critical errors. The 2 most common critical errors, referring to inhaler charging and positioning as well as inhaling/breathing errors, each accounted for 5 out of the 14 errors detected.

Other critical errors were incorrect lip and teeth placement around the inhaler mouthpiece (2 out of 14).


For each inhaler type, critical errors were observed for 10 out of 29 observations for DPIs and 4 out of 5 observations for MDIs. Two of the critical errors for MDIs were related to breathing.

The most common error in inhaler technique was not checking if there were any available doses in the inhaler before usage. However, investigators said that this may have been because participants were aware that they were using a placebo inhaler and may have assumed that a dose was available.

The researchers also found that patients with poor inhaler technique had a higher number of regularly prescribed medications than people who had no technique errors, and they were also older than those with no errors in technique. In addition, of those who were self-reported to be nonadherent to treatment, 29.5% performed critical errors in inhaler treatment.

The study had a number of limitations and the investigators urged caution in interpreting the results. The small sample size of participants means that the results may be over or understated and that they may not apply to a larger population of hospitalized patients. In addition, the patients were not recruited from respiratory units; if they had, the results might have been different. Moreover, given that the patients were hospitalized, they may not have been feeling well during the time or observation, or for privacy reasons, may not have answered the MARS-5 as fully as they would have otherwise. However, the investigators said that the results could serve “as a pilot to a larger study” and that they were in line with already published literature.

Investigators said that the results showed that interventions to improve inhaler technique and adherence medications are needed going forward.


Elander A, Gustagsson M. Inhaler technique and self-reported adherence to medications among hospitalized people with asthma and COPD. Drugs Real World Outcomes. October 14 2020;7(4):317-323. doi: 10.1007/s40801-020-00210-x.