Introduction
Asthma and chronic obstructive pulmonary disease (COPD) rank among the most widespread of chronic diseases contributing to morbidity and mortality in the world [1]
[2]
[3]. For the long-term treatment of these diseases, inhalation therapy with drugs being delivered directly to the lungs as an aerosol has become the method of choice as it allows high concentrations of the drug at the target site at a cost of negligible or acceptable systemic side effects [4]
[5]
[6]
[7]
[8]. In addition, another advantage of inhalation therapy is the quicker onset of action compared to systemic treatment [4]
[5]
[8]. For the purpose of inhalation therapy of asthma and COPD anti-inflammatory agents, primarily inhaled corticosteroids (ICS), and bronchodilators including both beta-2-adrenergic agonist and anticholinergics are currently being used [1]
[2].
However, optimal inhalation treatment is essential for deposition of the inhaled drug in the lungs [4]
[9]
[10]
[11]
[12]
[13]
[14]
[15]. This is dependent on the medication itself (type of inhaler device, particle size), but also on performing the inhaling action correctly [4]
[9]
[10]. Thus, the technique and performance of inhalation including device handling form integral parts of the drug deposition within the lungs [4]
[7]
[9]
[10]
[11]
[16]
[17].
As a matter of fact, optimal inhalation therapy is hindered by both intentional (patient’s beliefs, doubts, fears of adverse effects) and non-intentional (when the patient forgets to use the inhaler device or has no access to it) adherence to treatment [7]
[18]. In addition, even if the patient is willing and able to use the inhaler, a number of studies have identified patient-related mistakes in inhalation techniques being common, and this has been shown to be associated with reduced disease control [11]
[12]
[13]
[14]
[19].
Therefore, inhaler technique training is suggested to be a cornerstone of the care of patients with obstructive airway diseases to ensure optimal treatment. Furthermore, there are a number of strategies to choose the best inhaler device, and this is also aimed at improving the ability of the patient to correctly apply her/his prescribed inhaler [4]
[7]
[9]
[10]
[11]
[15]
[20]
[21].
Patient-related mistakes in inhalation techniques have been assessed differently in previous studies [11]
[12]
[13]. Typically, questionnaires and checklist have been used for the purpose of assessing correct inhalation. However, these tools differ considerably. In addition, application procedures and pitfalls are different amongst the various hand-held devices used for daily inhalation treatment. Finally, assessments of patient-related mistakes in inhalation techniques are not standardized. In this regard, it has been clearly established that patient-related mistakes in inhalation techniques might be related to inhalation preparation, inhalation routine, and closure of inhalation [22]. For these reasons, both scientific studies and different devices are not comparable to each other, respectively.
Therefore, the present study was aimed at developing checklists for frequently used hand-held devices used for inhalation treatment. These checklists were required to facilitate the comparison of different devices at least to some degree, but also to allow patients with different devices to be included in one study. In addition, it was an aim to standardize the checklists for the different parts of the inhalation manoeuvre, i. e. inhalation preparation, inhalation routine, and closure of inhalation. Moreover, the easy usage of the checklists in clinical practice was a prerequisite. Finally, the checklists were developed in German, but the finalized versions were later professionally translated into English. For this purpose, a translation and a back-translation by two independent translators were performed. The translated versions were refined to avoid incongruence between the original and the back-translated version where appropriate.
Methods
Checklists were developed for eight frequently used inhalers:
-
Aerolizer
-
Breezhaler
-
Diskus/Accuhaler
-
Handihaler
-
Novolizer
-
Metered-dose inhaler
-
Respimat
-
Turbohaler
The checklists were developed by an expert panel of pneumologists familiar with inhalation treatment (author group). Possible inhalation failures were adopted from previous research [7]
[11]
[12]
[13]
[14]
[18]
[19]. Accordingly, item formulation was primarily based on previous studies showing main mistakes in inhalation treatment. Ten items were formulated for each check list. Thereby, three items were formulated for the preparation of the inhalation process; six items were formulated for the inhalation routine; one item was formulated for the inhalation conclusion. Items for preparing and closure of inhalation were device-specific. For items covering inhalation routine the most important six possible mistakes were addressed as agreed within the expert panel. Thereby, the items for the inhalation routine were also formulated according to each device, respectively, but were closely related to each other according to the general rules of correct and optimal inhalation [22].
The checklists will be used by therapists evaluating the inhalation process of patients. For this purpose, each of the ten steps of inhalation will be rated as “failure” or “no failure”. Accordingly, each item consists of a positive statement (correct) and one negative (mistake) statement. The therapist must decide for each item if the step of the inhalation process is performed correctly or not. Subsequently, the number of mistakes can be counted in total or depending on the three categories as identified above, i. e. inhalation preparation, inhalation routine, and inhalation conclusion.
The initial checklists were shared within the board of the German Airway League (Deutsche Atemwegsliga e. V.). Refinements were made where appropriate.
Discussion
In the present study, checklists for the assessment of correct inhalation were developed by an expert panel of pneumologists working independently of any companies that produce the devices, in order to assure face validity.
The checklists are available in German and in English. They can be downloaded free of charge for non-profit projects from the homepage of the German Airway League (Deutsche Atemwegsliga) [www.atemwegsliga.de]. These checklists can be used for clinical application, but are also appropriate for clinical trials, particularly if different devices are used in one study.
The current project is aimed at stimulating the research in the field of inhalation treatment. Today, more and more drugs, drug combinations, and devices for inhalation therapy are available [4]
[6]
[8]
[15]
[23]
[24]. In this regard, randomized controlled trials have clearly established the benefits gained by inhalation treatment in obstructive lung diseases [11]
[12]
[13]. However, the evidence gained by randomized controlled trials is typically based on optimal circumstances also concerning correct inhalation. In real life, steadily improved inhalation treatment strategies as established by randomized controlled trials are worthless if high failure rates of the inhalation technique attenuate the treatment success.
Based on this, the current project is in line with a previous project from the German Airway League, where video screens for correct inhalation were provided as an efficient and globally available platform of information for both patients and therapists. Here, correct use of all inhalation devices available in Germany has been videotaped and published via internet and DVD, with video screens, spoken text passages, and the visual insertion of information, all available free of charge on the homepage of the German Airway League [www.atemwegsliga.de] [20]
[25]
[26]
[27]. The videotaped information is updated continuously.
As a limitation, the checklists were developed by pneumologists not regularly involved in the treatment of children. Therefore, the checklists are valid for adult patients only. Even though the current authors would not exclude that the checklists could also be successfully used in paediatric patients, specific aspects related to mistakes typically performed by children were not addressed. In addition, direct comparability between different devices is naturally hindered, and this is particularly due to main differences for preparing device-specific inhalation. Nevertheless, as all checklists refer to their main mistakes as established, it appears feasible to figure out what device is individually associated with overall lower mistake rates compared to others. Thus, certain comparability between different devices in terms of device-related failure rates is suggested to be feasible.
Therefore, the currently developed checklists are also suggested as a capable means of identifying patients who could benefit from inhalation training. In this regard, the teaching videos would be helpful, because these screens do not just cover the inhalation routine, but also the process of preparation and closure of inhalation.
