Are Our Patients With Asthma Still Using Inhalers Incorrectly?

Aim. To determine how skilled our patients with asthma are in performing different steps in the use of different inhalation devices, and to identify variables that may influence correct inhalation technique (IT). Design. Descriptive, cross-sectional study. Setting. An urban primary care center. Participants. 141 patients with asthma. Main outcome measures. Performance of a practical test to evaluate each step in IT for different devices according to SEPAR-semFYC guidelines. One point was scored for each step that was performed correctly, and the technique was considered correct if the total score was >9. The main outcome variable was the percentage of patients who performed the IT correctly. Results. About three-fourths of the participants (77.3%) were women; mean age was 56.08±18.99 years. Inhalation technique was incorrect in 53.9% of the patients (51.06% of those who used a pressurized canister inhaler, 59.1% of those who used a PCI+spacer, 38.5% of those who used a Turbuhaler, and 37.5% of those who used an Accuhaler). The highest error rates were seen in exhaling completely before beginning the inhalation (63.78%), holding the breath after inhalation for as long as possible (65.94%), and breathing out slowly after the inhalation (64.86%). Better IT was seen in younger patients with higher levels of education ( P=.007). There were no statistically significant differences in the rest of the variables. Conclusions. A large percentage of patients performed inhalations incorrectly. We cannot conclude that any given device is superior. The variables related with correct IT were age and level of education. Greater health education efforts are needed to teach patients how to use inhalation systems correctly.

Objetivo. Conocer la destreza de nuestros pacientes asmáticos en la realización de las maniobras de los diferentes sistemas de inhalación, así como determinar las posibles variables que puedan influir en la correcta realización de la técnica inhalatoria (TI). Diseño. Estudio descriptivo transversal. Emplazamiento. Centro de atención primaria urbano. Participantes. Un total de 141 asmáticos. Mediciones principales. Realización de un test práctico donde se evaluaba paso a paso la TI para cada uno de los diferentes sistemas de inhalación siguiendo las normativas SEPAR-SemFYC. Por cada maniobra correctamente realizada, se asignaba un punto. La técnica se consideraba correcta si se obtenía una puntuación total > 9. La variable principal fue el porcentaje de pacientes que realizaban bien la TI. Resultados. Un 77,3% eran mujeres, con una media de edad de 56,08 ± 18,99 años. La TI fue incorrecta en el 53,9% de los pacientes (el 51,06% de los que utilizaban inhalador de cartucho presurizado [ICP], el 59,1% de los ICP + cámara, el 38,5% de Turbuhaler y el 37,5% Accuhaler). Las maniobras con mayor porcentaje de error fueron: espiración previa a la inhalación (63,78%), mantenimiento de la apnea postinspiración (65,94%), espiración lenta tras la inhalación (64,86%). A menor edad y mayor nivel de estudios, se constataba una mejor realización de la TI (p = 0,007). No se encontraron diferencias estadísticamente significativas en el resto de variables. Conclusiones. Se produjo un elevado porcentaje de pacientes con TI incorrecta. No podemos concluir que exista un sistema mejor que otro. Las variables relacionadas con la correcta realización de la TI son la edad y el nivel de estudios. Es necesario intensificar la educación sanitaria sobre el manejo de los diversos sistemas de inhalación.

Introduction

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Although inhalation is the route of delivery of choice in the treatment of asthma, inhalers are often used incorrectly.^1-7 Many patients have received no instruction in inhalation technique (IT), and even many health care professionals do not know the correct steps.^8-11 Earlier studies have evaluated the skills of patients with asthma in the use of pressurized canister inhalers (PCI), but data on the use of other devices are scarce. Few studies of this type have been done in the primary care setting. Despite the publication of clinical practice guidelines,^12-15 we suspect that IT is still often performed incorrectly. This led us to investigate our patients' skills in performing the steps needed to use different inhalation systems, and the variables that can influence correct performance.

 

Methods

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Study design

Descriptive, cross-sectional study.

Participating center

An urban primary care center and primary care staff.

Study group selection

We included all patients aged 18 to 80 years and diagnosed as having asthma who were registered with the program at our center (n=281 patients).

Inclusion criteria

Seen for more than 1 year for asthma, and 1 or more prescriptions for inhaled medications during the preceding 2 years.

Exclusion criteria

Declining to participate in the study, missing an appointment or not locatable, problems traveling to the center, incapacitating neurological or psychiatric disorders, terminal neoplasm, or advanced AIDS.

We reviewed the clinical history of all patients to record the following variables: sex, age, educational level, year of diagnosis, classification of asthma according to the GINA 98 system,¹⁶ treatment, inhalation system used, and physician responsible for the patient. With the doctor's or nurse's permission, each participant was contacted by telephone (up to four attempts) at different times of day to schedule an individual appointment for an IT test. If no phone number was recorded, we went to the patient's home.

On the basis of these inclusion and exclusion criteria, a total of 141 patients were recruited to investigate IT.

Description of the IT evaluation test

Each patient was asked to demonstrate how they used their inhaler; no information was provided prior to the test. Each step in the process was checked in accordance with SEPAR-semFYC guidelines.^12,13 For scoring purposes the technique was broken down into several steps; for each step performed correctly, 1 point was scored. The technique was considered incorrect when the total score was >9. For patients who used more than one inhaler system, the results were analyzed separately for each device. If one of the techniques was performed incorrectly, the patient's IT was considered incorrect.

Outcome measures

Main outcome variable: percentage of patients with correct IT. We analyzed the percentage of patients with correct IT for each inhalation system separately, and for all systems globally. The percentage error rates were compared for each step and for each system. As secondary variables we analyzed factors that could influence IT performance.

Statistical analysis

Ninety-five percent confidence intervals for the percentage error rates were calculated, and bivariate analysis was done with comparison of the means (Student's t test) and comparison of the proportions (χ²). All analyses were done with version 10.0 of the SPSS.

 

Results

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Of the 141 patients, 77.3% (n=109) were women, and mean age was 56.08 (SD, 18.0) years. The different inhalation systems used by our patients are shown in Table 1. About three-fourths of the patients (73.8%) used only one inhalation device (n=104), 21.3% (n=30) used two systems, and 5% (n=7) used three, thus the total number of inhalation systems we checked in this study was 185. When the only device used was a PCI, the active principle was a short-acting ß₂ in 90% of the prescriptions. When more than one system was used, a PCI was one of the devices used by most patients.

Overall, IT was incorrect in 53.9% (n=76) of the patients. The Accuhaler and Turbuhaler systems yielded the highest scores (correct IT in 62.5% and 61.5% of the patients, respectively). The system that yielded the highest percentage of errors (59.1%) was PCI+spacer (Table 1).

The steps with the highest percentage error rates for all inhalation systems are shown in Table 2. Younger patients and patients with a higher educational level more frequently used inhalation systems correctly (P=.007) (Table 3).

Mean age of the patients who used different systems was: Turbuhaler, 42.5 (±18.82) years; Accuhaler, 68.25 (±2.87); PCI, 55.48 (±21.21; PCI+spacer, 64.28 (±14.63), and dry powder inhaler, 41. The percentage of patients who had received university-level education, by inhalation system, was Turbuhaler, 36.5%; Accuhaler, 18.8%; PCI, 14.9%, and PCI+spacer, 7.6%.

There were no statistically significant differences in the percentage rates of correct IT and any of the other variables shown in table 3 (P>.05).

 

Discussion

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Studies of the prevalence of asthma indicate that 1% to 5% of the population have this disease.^14,17 In our study, 1.8% of the population had asthma. The higher percentage of asthma in women may reflect their greater use of health care services. Underrecording was found for both the prevalence and classification of asthma. This finding may reflect the fact that health care staff are less aware of this disease than they are of others. As reported in an earlier study,³ a large percentage of our patients used their PCI without a spacer. The fact that most patients used short-acting ß₂ on an as-needed basis may account for this finding.

Patients who were taking different medications via a PCI used a spacer, as recommended by current guidelines.^13-15 Use of a single inhalation system is advisable to favor compliance with instructions for IT.¹⁸

In the present study we found that IT was worse in patients who used more than one inhaler. The number of errors was proportional to the number of devices used, although this relationship was not statistically significant. As in other studies, the percentage of patients with incorrect IT was high.^1-5,9-11 The similarities in error rates may reflect inadequacies in the instructions patients receive.³ As in other published studies, the steps that were most frequently performed incorrectly were exhaling completely before inhaling the dose^1-3 and holding the breath after inhalation.^1,2,4 Patients who used a Turbuhaler made fewer mistakes.

When we analyzed the relationship between mean age and level of education and the inhalation system used, we found these variables to be confounders in our attempt to identify the best inhalation system: the system that appeared to be the best (Turbuhaler) was used predominantly by younger patients with a higher level of education. To offset the influence of these confounders we stratified the results by age group and re-examined the results to identify which inhalation system was used best in each subgroup. In both age subgroups (i.e., in patients older than and younger than 65 years), the inhalation devices that were used correctly most often were Turbuhalers and Accuhalers, although the difference in comparison to other systems was not statistically significant (probably because of the small sample size).

Our findings suggest that the Turbuhaler device is superior to the rest. However, to confirm this, patients would need to be selected in a manner that ensured a homogeneous distribution, in terms of age and level of education, of participants who use different inhalation devices. Our results also suggest that when a specific inhalation system is singled out for analysis, each case should be dealt with individually according to the subject's characteristics.^4,13,14 As in other studies, the variables that were most clearly related with correct IT were age⁴ and level of education.³

In conclusion, we note a large percentage of our patients with asthma had errors in their inhalation technique. Health education efforts to teach patients how to use different inhalation devices correctly should be stepped up. Our study does not allow us to conclude that any one inhalation device is superior to the others. Future research will compare IT performance with different inhalation devices, taking into account the confounding factors identified above. We will also evaluate whether educational group workshops are effective in improving inhalation technique.

 

Correspondence: Montserrat Rodríguez Mas. C/ Torras i Bages, 1. 08290 Cerdanyola del Vallès (Barcelona). España. E-mail: [e-mail]

 

Received 11 December 2002. Accepted for publication 21 May 2003.