An intervention to improve the inhalatory technique of children and adolescents with asthma
M. Gracia-Antequera* and M. M. Morales Suárez-Varela**
*Department of Pediatrics, at Hospital Universitario Doctor Peset. Valencia. Spain. **Clinical and Epidemiological Research Unit, at Hospital Universitario Doctor Peset; and Public Health, Hygiene and Environmental Health Unit, at Universitat de Valencia. Valencia. Spain.
Correspondence:
Miguel Gracia Antequera
Department of Pediatrics
Hospital Universitario Doctor Peset
Avda. Gaspar Aguilar, 90
46017 Valencia
Spain
SUMMARY
Background: most patients use their inhalers incorrectly and recent asthma management clinical guidelines recommend demonstrating skills and correcting performance at each asthma follow-up visit. However, this statement is poorly evidence-based and few intervention studies have assessed quantitatively the effectiveness of this recommendation.
Methods: from a total of 3,076 children and adolescents with asthma attending an outpatient clinic, a random, representative sample of 255 was obtained and assessed at baseline with a standardised questionnaire regarding their skills when using one of three inhaler devices: pressurised direct aerosol (PDA), dry powder (DP) and aerosol pressurised in expanded camera (APEC). Structured sessions of correct use and handling of inhalers were offered and a new assessment was undertaken after an average of 10.5 months (SD 4.5).
Results: only 142 asthmatics maintained the same inhaler device during the study period. An increase of correct manoeuvres was observed for all three devices, and the relative risk and 95% confidence interval (RR and 95% CI) of incorrect post-intervention use was 0.23 (95% CI 0.10-0.56) for PDA, 0.59 (95% CI 0.38-0.92) for DP, and 0.54 (95% CI 0.32-0.90) for APEC. A multivariate analysis indicates that this improvement was observed irrespective of gender and age interval, and that it was even better when parents cooperated with medical and nursing staff.
Conclusions: a dramatic improvement in correct manoeuvres with any of three inhaler devices after active performance training was observed. This easy, highly effective, low cost (in terms of time and personnel) intervention should be routinely implemented in any control visit of asthmatics, leading to a better management of asthma.
Key words: Childhood asthma. Inhaled treatment. Intervention. Therapeutic instruction. Effectiveness.
RESUMEN
Introducción: una gran cantidad de pacientes utilizan sus inhaladores de manera incorrecta. Las guías clínicas más recientes sobre el manejo del asma recomiendan que en cada visita de seguimiento del paciente se realicen demostraciones de su habilidad en el manejo del inhalador y se hagan las correcciones necesarias. Sin embargo, estas medidas se basan débilmente en la evidencia y se han realizado pocos estudios que aseguren cuantitativamente la efectividad de estas recomendaciones.
Métodos: de un total de 3.076 niños y adolescentes con asma atendidos en las consultas externas del Hospital, se obtuvo una muestra randomizada representativa de 255 individuos y se valoró, mediante un cuestionario estandarizado, su destreza en el manejo de uno de estos tres tipos de inhaladores: aerosol presurizado directo, polvo seco y aerosol presurizado en cámara. Tras una primera valoración se recordaba su uso, realizando un nuevo control transcurridos 10,5 ± 4,5 meses.
Resultados: sólo 142 pacientes con asma bronquial mantuvieron el mismo tratamiento con el mismo tipo de inhalador durante el período de estudio. Se observó un incremento en las maniobras correctas en los tres tipos de inhaladores estudiados y el riesgo relativo y el intervalo de confianza al 95% (RR e IC 95%) de las maniobras incorrectas tras la intervención fueron: aerosol presurizado directo RR de 0,23 (CI 95%: 0,10-0,56), dispositivo de polvo seco RR de 0,59 (IC 95%: 0,38-0,92), y con aerosol presurizado en cámara, el RR fue de 0,54 (IC 95%: 0,32-0,90). Al realizar un análisis multivariante se observó que la mejora obtenida era independiente del sexo y del intervalo de edad y que era mayor cuando los padres cooperaban con los médicos y el personal de enfermería.
Conclusiones: se observó un incremento de maniobras correctas con los tres dispositivos tras la explicación de manejo. Esta intervención de fácil realización, de gran efectividad y bajo coste (en términos de tiempo y personal) podría ser introducida de manera rutinaria en cualquier visita de control de los pacientes asmáticos, lo que llevaría a una mejora en el tratamiento del asma.
Palabras clave: Asma infantil. Tratamiento inhalatorio. Intervención. Instrucción terapéutica. Efectividad.
INTRODUCTION
In 1992 the International Consensus for the Diagnosis and Treatment of Asthma determined the importance of the inflammatory component in asthma, and inhaled antiinflammatory medication was considered the most effective therapy for this disorder both in children and adults (1). However, in spite of the technical advances made to enable this method to be used even in very young children, the effectiveness of inhaled therapy continues to depend highly on the manner in which it is actually administered. Indeed, several authors have indicated the necessity of adding to the pharmacological therapy adequate, regular education programs for patients, parents and relatives, teachers and other personnel (2-4) because up to 70% of the patients use the inhalers incorrectly (5). Indeed, the very recent Asthma Management Clinical Guidelines of the National Heart, Lung and Blood Institute recommend demonstrating skills and correcting inhalatory performance at each asthma follow-up visit (6). However, this statement is poorly evidence-based and few intervention studies have assessed quantitatively the effectiveness of this recommendation. Indeed, even after active reminders, a recent report indicates that a set of Dutch GPs seeing asthma patients checked on inhalation technique in only 38% of the visits (7). Therefore, the main objective of this study was to assess the effectiveness of an intervention to improve inhalatory skills for the treatment of children and adolescents with asthma. In addition, it was also intended to identify variables that could be implicated in the improvement of the use of these devices in the long term.
MATERIAL AND METHODS
During the two year period from November 1993 to December 1995, a total of 14,649 children were enrolled in a controlled trial in the outpatient Paediatric section of our hospital. 3,076 were seen due to asthma, the large majority of them managing their disease by means of inhaled treatment. Of these patients, a random sample of 255 was selected and 142 (55.7%) completed the follow-up study with the same inhalatory device. All participants were given a comprehensive questionnaire to assess the management, correct or incorrect, of their inhalator medication. After this assessment, medical or nursing personnel proceeded to demonstrate the correct management technique (described below), and after an average of 10.5 months (SD 4.5), a second assessment of inhalatory skills was undertaken.
In each evaluation, the child or adolescent was presented with the same treatment that he/she customarily uses in his/her own asthma management and the procedures for better administration of their inhaled medication were carefully reviewed. The three inhalation methods assessed were:
-- Pressurised Direct Aerosol (PDA), in which the child applies the inhaler directly in his/her mouth and activates the valve that releases the aerosol while taking a breath.
-- Dry Powder device (DP), using a dispenser for the dose of powder that the patient must inhale, inspiring it directly.
-- Aerosol Pressurised with Expansion Chamber (APEC), a device with which the aerosol is linked, facilitating the penetration of the drug into the airways and not requiring coordination of the inspiration with the activation of the inhaler.
In each one of the three methods mentioned above, five characteristic milestones of good usage were identified, namely: 1) adequate preparation of the dose, agitating the container or loading the dry powder device; 2) deep expiration; 3) correct application in the mouth of the medication dispenser; 4) slow and deep inspiration; and 5) maintaining the inspiration for five to ten seconds. These five steps are very similar to the ones recently included in the NHLBI asthma guidelines (6).
The performance of each patient was monitored and scored for their good accomplishment of every step, and a global score was obtained for the inhalator technique in each one of the three indicated methods.
Drugs taken for the three methods were of four types: short acting beta-2 agonists (salbutamol, fenoterol or terbutaline); long acting beta-2 agonists (salmeterol or formoterol); membrane protectors (cromoglicate or nedocromil); and corticosteroids (beclometasone or budesonide). Variables considered in the study were the age of the patients at each test, their gender, who carried out the explanation and the control of the treatment, and the months of duration of treatment before the first test and between both tests. The outcome was assessed according to the inhaler device, assessing the punctuation scored after completion of the survey.
Statistical analysis
Pearson''s Chi2 test for paired samples was calculated for the correct management of each inhaler before and after the intervention. An effect estimator similar to a relative risk was obtained; so the relative risk of incorrect use was the quotient between the rate of incorrect manoeuvres prior to the intervention over the rate of incorrect manoeuvres after the intervention. Analyses were performed with SPSS version 6.1 for Windows and EPIINFO 5.0. Statistical significance is reported two tailed at the 5% level.
RESULTS
Asthma represents 12.4% of the total burden of disease in our paediatric outpatient department. Of these patients, a random sample of 255 was selected and 142 (55.7%) completed the follow-up study with the same inhalatory device. Of these 142 patients that were maintained using the same inhaler during the study period, 103 were boys (72.5%) and 39 girls (27.5%), that is a male/female ratio of 2.64. The mean age of patients before the intervention was 10.5 years (SD 4.6), corresponding to the greater frequency interval from 7 to 12 years old with 57.0% of the total (81 children). At the post-intervention assessment, the mean age was 11.5 years (SD 4.6).
Drug treatment varied moderately during the study period: at post-intervention, 125 (88.0%) patients had received short-acting beta-2 agonists versus 93.7% prior to intervention; for long acting beta-2 agonists 2.1% before and 2.8% after; cromones were used by 69 (48.0%) patients before and 42.5% afterwards; finally, steroids were maintained in 19% before and after.
The method of administration of inhaled medication by these young patients was: 45 children (31.7%) with APD, 44 children (31.0%) with DP and 74 children (52.1%) with APEC. Similarly, after the intervention the results obtained were: 40 children (28.2%) with APD, 41 children (28.9%) with DP and 73 children (51.4%) with APEC.
The association of age with correct application of the treatment is presented in table I. The same pattern is observed in all three methods but, after stratification by age, a statistically significant increase is observed for 9 to 14 year old children who correctly used APD (p < 0.001) and DP (p < 0.01) in the post-intervention period, while in APEC the percent increase of correct manoeuvres is borderline significant (p < 0.06).
| Table I Inhaled treatment in children with asthma. Distribution of asthmatic children by age and sex according to inhaler device. Comparison of correct performance before and after an intervention | ||||||
| Age | PDA | DP | APEC | |||
| Pre n-N (%) | Post n-N (%) | Pre n-N (%) | Post n-N (%) | Pre n-N (%) | Post n-N (%) | |
| 5-8 | 5-7 (71.4) | 3-3 (100) | 3-7 (42.9) | 1-4 (25.0) | 18-32 (56.2) | 17-24 (70.8) |
| 9-14 | 9-24 (37.5)* | 19-21 (90.5) | 8-27 (29.6)* | 17-26 (65.4) | 23-37 (62.2) | 34-42 (80.9) |
| 15-22 | 7-14 (50.0) | 13-16 (81.2) | 4-10 (40.0) | 7-11 (63.6) | 3-5 (60.0) | 6-7 (85.7) |
| Gender Boy | 15-34 (44.1)* | 27-31 (87.1) | 12-30 (40.0) | 18-30 (60.0) | 27-51 (52.9)* | 38-50 (76.0) |
| Girl | 6-11 (54.5) | 8-9 (88.9) | 3-14 (21.4)* | 7-11 (63.6) | 17-23 (73.9) | 19-23 (82.6) |
| Total | 21-45 (46.7)* | 35-40 (87.5) | 15-44 (34.1)* | 25-41 (61.0) | 44-74 (59.5)* | 57-73 (78.1) |
| The three inhaler devices are: pressurised direct aerosol (PDA), dry powder (DP) and aerosol pressurised in expansion chamber (APEC). | ||||||
Regarding gender (table I), statistically significant increases for the percentage of satisfactory manoeuvres after the intervention were observed both in boys and girls. Overall the inhaler with better performance was PDA (87.5%), followed by APEC (78.1%) and finally DP (61.0%). In terms of who conducted the explanation prior to the study and between the controls, an increase in the percentage of correct manoeuvres (table I) in the use of the three inhalers after training by medical or nursing personnel was observed (table II). The small number of patients instructed by parents or other relatives limits any further analysis of this aspect.
Table II Comparison of correct performance according to inhaler device by different administrators of the information | ||||||
| Explained by: | PDA | DP | APEC | |||
| Pre n-N (%) | Post n-N (%) | Pre n-N (%) | Post n-N (%) | Pre n-N (%) | Post n-N (%) | |
| GP-nurse | 19-38 (50.0) | 35-38 (92.1) | 15-42 (35.7) | 25-41 (61.0) | 37-64 (57.8) | 57-73 (78.1) |
| Parents | 2-4 (50.0) | 0-2 (0) | 0-1 (0) | 0-0 (0) | 1-1 (100) | 0-0 (0) |
| No response | 0-2 (0) | 0-0 (0) | 0-0 (0) | 0-0 (0) | 2-2 (100) | 0-0 (0) |
| Prescription | 0-1 (0) | 0-0 (0) | 0-0 (0) | 0-0 (0) | 4-7 (57.1) | 0-0 (0) |
| Controlled by: No response | 0-1 (0) | 0-0 (0) | 0-0 (0) | 0-0 (0) | 1-1 (100) | 0-0 (0) |
| Parents | 14-23 (60.9) | 15-18 (83.3) | 7-25 (28.0) | 15-26 (57.7) | 37-63 (58.7) | 48-62 (77.4) |
| Patient | 7-21 (33.3) | 19-21 (90.5) | 8-19 (42.1) | 10-15 (66.7) | 5-9 (55.6) | 9-11 (81.8) |
| Parents & patient | 0-0 (0) | 1-1 (100) | 0-0 (0) | 0-0 (0) | 1-1 (100) | 0-0 (0) |
| The three inhaler devices are: pressurised direct aerosol (PDA), dry powder (DP) and aerosol pressurised in expansion chamber (APEC). | ||||||
Therefore, who gives instruction about the administration of the treatment is important (8). An analysis of the relative frequencies of correct usage after the intervention (table II) indicates that the instruction of patients in the administration of their own treatment is beneficial with PDA (p < 0.001), and the results are similar also where the parents give instruction on the use of DP (p = 0.03) or APEC (p = 0.02).
As reported previously, the average time elapsed between the two assessments was 10.5 months, and the majority group corresponded to those with more than one year of treatment. In table III the relationship between the duration of treatment, the three types of inhaler and the results of correct application pre- and post-intervention is presented, showing an association for the relative increase of satisfactory manoeuvres (p < 0.05) at all age intervals.
Table III Association between correct utilisation of inhaler devices and time since starting treatment | ||||||
| Months in treatment | PDA | DP | APEC | |||
| Pre* n-N (%) | Post n-N (%) | Pre* n-N (%) | Post n-N (%) | Pre* n-N (%) | Post n-N (%) | |
| ¾ 6 | 0-1 (0) | 7-7 (100) | 1-2 (50.0) | 2-2 (100) | 6-11 (54.6) | 16-17 (94.1) |
| 7-12 | 7-10 (70.0) | 21-24 (87.5) | 3-9 (33.3) | 20-30 (66.7) | 18-25 (72.0) | 31-42 (73.8) |
| >= 13 | 14-34 (41.2) | 7-9 (77.8) | 11-33 (33.3) | 3-9 (33.3) | 20-38 (52.6) | 10-14 (71.4) |
| The three inhaler devices are: pressurised direct aerosol (PDA), dry powder (DP) and aerosol pressurised in expansion chamber (APEC). | ||||||
DISCUSION
The results of this study suggest that, for the three types of inhalers considered, instruction and education have a positive effect in terms of better utilisation of inhalatory devices.
Inhaled therapy is the preferred option for the administration of treatment for children with asthma (9-14) and several authors (15, 16) suggest prescribing the inhaler device as it is most likely to be accepted and complied with. But, as Smith et al (3) point out, the choice of the inhalatory device as well as confidencence to use it correctly are both crucial aspects in ensuring the efficiency of the therapy and a good control of the disease. Apart from the proper aerosolised drug, respiratory frequency and apnoea time are also important steps in maximising the efficiency of delivery. Therefore, breathing deeply and holding the breath for 5-10 seconds were also included on the checklist.
For the same active treatment, some froms of dry powder and inhalers provided with space chambers have been demonstrated in several trials to be better than PDA aerosolised compounds, due to higher delivery directed straight to the bronchioles. However, and contrary to our initial hypothesis for preferring APEC or DP devices, a substantial percentage of children (28.2%) were still using PDA, most likely due to the smaller amount of time required for its management, or perhaps because it is comfortable to use and easy to transport outside the home. A particularly problematic aspect of DP was the bad habits acquired in the preparation of the dose with this inhaler, observed in 28.9% either pre- or post-intervention.
The most conclusive finding of this study is the improvement in correct manoeuvres with all three devices. This increases from 46.8% before training to 75.5% afterwards. Unexpectedly, the largest improvement was in APD, possibly because the patients made a greater personal effort because it is comfortable to use (as mentioned above). Interestingly, it is with this same inhaler that, in the 9 to 14 years group, training on correct usage considerably reduced the risk of incorrect utilisation from 4.17 (0.52-50.8) to 0.60 (0.04-39.28). Though these results lack statistical significance they point towards the effectiveness of new interventions and medical education programs. The recent introduction in the market of the system Autohaler will help with the application of APD still further, because the dose is automatically fired upon beginning the inspiration.
Several limitations of this study deserve to be considered, namely, response rate, length of follow-up and allocation of inhalers. Response rate is always a concern in any observationals study, especially with a one-year follow-up period as in the study presented. Moreover, this was not a randomised controlled trial, and therefore allocation to the three inhaler devices was not random, particularly since some devices are less appropriate for younger ages. We introduced controls for age and other confounders retrospectively, and so this should not be a major drawback for the overall interpretation of our conclusions. Finally, the extended length of time between the first and the final assessment produces concerns about causality, since continuous, regular use of an inhaler device of itself leads to better skills over time because of better intellectual development, more practice or simply self-learning. However, our sensitivity analysis on duration of use points against this statement.
Our results suggest that medical personnel should be in charge of the regular explanations on the use of inhaler devices, as endorsed by the significant increase, both clinical and statistical, of correct manoeuvres in all the inhalers under these circumstances (table II). Indeed this was observed the most in adolescents, who want to control by themselves their medication (17). This was also observed with APD, which maintained the greatest risk of wrong application after the intervention, RP of 2.06 (0.24-15.12), possibly due to the fact that less attention is paid in the execution of the manoeuvre, perhaps because it becomes part of the daily grind of the patient, or because the difficulties of an oncoming asthma attack outweigh the need for medication.
Regarding management control, for all three devices a progressive increase in inadequate handling was observed as the time following the intervention increased, reaching statistical significance (table III). Therefore, regular repetition of the training, at least every six months, should be encouraged, as indicated in recent guidelines.
It is our opinion, shared by other authors (18-20) that time spent in monitoring the management of inhalatory devices in children with asthma is a key issue for a favourable outcome. In this way incorrect methods of delivery of a therapy in a given patient will not be attributed to incorrect therapy, and this should help medical staff to comply confidently with prescribed therapy. Most regimens are complex and tedious, requiring several medications simultaneously, and success rate in asthma management has been conditioned to the ability of the patient to fulfil medical prescriptions (21).
To conclude, this study provides evidence that regular assessment of inhalatory techniques with any of the three inhalator devices surveyed, namely PDA, DP or APEC, is needed to improve asthma management and effective drug delivery, and that this is particularly necessary in children older than 8 years who tend to selfmanage their asthma and have been using the same inhaler for longer than one year.
ACKNOWLEDGEMENTS
We thank Joan B. Soriano and Alex Sexton for editorial assistance.
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