Asthma control and morbidity: a comparison of inhaler devices

A New Quantitative Method for Evaluating Dry Powder Inhalation Efficiency in Asthma Patients

PURPOSE

Many methods have been developed to evaluate dry powder inhalation techniques and their efficiency for disease control in asthma patients. However, it is difficult to apply these methods to clinical practice and research. In this study, we introduce a simple new method that can be applied to dry powder inhalation techniques to evaluate their efficiency in clinical practice.

METHODS

Twenty volunteers were recruited to evaluate the reliability of this new method. One hundred one asthma patients who met the inclusion criteria participated in this study. A dark cloth covered the outlet of the inhaler during dry powder inhalation. The image formed by the inhalation process was evaluated using analysis software and converted into integrated optical density (IOD). Inhalation techniques were scored before and after inhalation technique training, and asthma control was evaluated using the Asthma Control Questionnaire (ACQ) before inhalation technique training.

RESULTS

The relative standard deviation of IOD ranged from 3.8% to 7.8%. In patients with or without inhaler prior use, both the IOD and inhalation technique scores improved significantly after inhalation technique training (p < 0.05). Inhalation technique scores were positively correlated with IOD before (r = 0.80, p < 0.001) and after inhalation technique training (r = 0.52, p < 0.001). In patients with prior inhaler experience, ACQ results were negatively correlated with inhalation technique scores (r = -0.44; p < 0.05) and IOD (r = -0.52; p < 0.05).

CONCLUSION

The results from this study demonstrated that this quantitative method is equivalent to traditional methods for dry powder inhalation evaluation. This study also indicated that training significantly improved the inhalation technique and efficiency in asthma patients with or without prior inhaler use.

Comparison of patient preference and ease of teaching inhaler technique for Pulmicort Turbuhaler versus pressurized metered-dose inhalers

A multicenter, randomized, open-label, crossover study with two 4-week evaluation periods compared patient preference and ease of teaching correct inhaler technique for Pulmicort Turbuhaler versus pressurized metered-dose inhalers (pMDIs). Patients 18 to 65 years of age with stable, mild to moderate asthma, who required or were eligible for inhaled corticosteroid therapy, were randomized to treatment sequences consisting of 4-week evaluation periods with Pulmicort Turbuhaler (budesonide inhalation powder) two puffs (400 microg) bid and one of three inhaled corticosteroids via pMDI: Aerobid-M (flunisolide) four puffs (1 mg) bid, Flovent (fluticasone propionate) two puffs (440 microg) bid, or Vanceril Double Strength (beclomethasone dipropionate) five puffs (420 microg) bid. Patients indicated device preference at study end and completed the Patient Device Experience Assessment (PDEA) questionnaire after each evaluation period. Ease of teaching, time required to master use of the device, percentage of patients demonstrating mastery on the first attempt, and the number of attempts required to demonstrate mastery were assessed. Despite previous use of pMDIs by most patients, Pulmicort Turbuhaler was significantly preferred (p < 0.001) and required significantly less time to master than pMDIs (p < 0.001). Median times to device mastery were 3.67 min for Pulmicort Turbuhaler versus 5.33 min for pMDIs. Patients rated Pulmicort Turbuhaler significantly better than pMDIs on PDEA ease of use (p = 0.0005) and overall satisfaction (p < 0.0001) single-item scales and all four multi-item scales (pharyngeal symptoms, oral sensation, operational use, and inhaler attributes; p < 0.05). Overall, patients preferred Pulmicort Turbuhaler over pMDIs and required less time to be taught how to correctly use Turbuhaler trade mark.

Pressurised metered dose inhalers versus all other hand-held inhaler devices to deliver beta-2 agonist bronchodilators for non-acute asthma

BACKGROUND

A number of different inhaler devices are available to deliver beta2-agonist bronchodilators in asthma. These include hydrofluoroalkane (HFA) or chlorofluorocarbon (CFC)-free propelled pressurised metered dose inhalers (pMDIs) and dry powder devices.

OBJECTIVES

To determine the clinical effectiveness of pMDI compared with any other available handheld inhaler device for the delivery of short-acting beta-2 agonist bronchodilators in non-acute asthma in children and adults.

SEARCH STRATEGY

The Cochrane Collaboration Clinical Trials register was searched for studies as well as separate additional searches carried out on MEDLINE, EMBASE, CINAHL and also on the Current Contents Index as well as the Science Citation Index. In addition, 17 individual online respiratory journals and 12 electronically available clinical trial databases were also searched. The UK pharmaceutical companies who manufacture inhaled asthma medication were contacted in order to obtain details of any published or unpublished studies.

SELECTION CRITERIA

- The full texts of all potentially relevant articles were reviewed independently by two reviewers.

DATA COLLECTION AND ANALYSIS

Fixed and random effect models were used. Dichotomous outcomes were assessed using Odds Ratios or Relative Risks (RR) with 95% Confidence Intervals (95%CI).

MAIN RESULTS

Eighty-four randomised controlled trials were included in this review, but few could be combined to assess a specific outcome for a given delivery device comparison. Only two studies required demonstration of adequate pMDI technique as an entry requirement. There were no difference between a standard CFC containing pMDI and any other device for most outcomes. Regular use of HFA-pMDI containing salbutamol reduced the requirement for short courses of oral corticosteroids (3 trials, 519 patients: RR 0.67; 95% CI 0.49, 0.91); however the total number of exacerbations were unchanged (3 trials, 1271 patients: RR 1.0; 95% CI 0.75, 1.33).

REVIEWER'S CONCLUSIONS

In patients with stable asthma, short-acting beta-2 bronchodilators in standard CFC-pMDI's are as effective as any other devices. The effect of HFA-pMDI on requirement for oral corticosteroid courses to treat acute exacerbations should be confirmed. Effectiveness studies that use an intention-to-treat analysis are required.

Asthma inhalation delivery systems: the patient's viewpoint

International guidelines for asthma management state that inhalation is the preferred route of drug delivery. Consequently, it is important to select an appropriate delivery device and to take account of a patient's preference and lifestyle, as incorrect inhaler use may lead to treatment failure. A large number of devices are available from which to select, but it may be difficult for healthcare professionals to provide guidance to the patient unless they are familiar with the characteristics and correct use of each device. Many factors affect the success of a device in a patient's hands: the device's features; the patient's psychosocial status, cultural beliefs, and language skills; and consistent instruction on inhalation technique. Constant education is essential to establish and maintain the patient's confidence in the treatment regimen. It is important that at least one member of the respiratory healthcare team should remain abreast of medical and pharmaceutical developments in the respiratory field. In this way, the choice of delivery device can be reviewed and changed to suit the changing needs of the patient.