Inhaled therapy remains the most effective and important aspect of asthma maintenance treatment for patients of all ages5,7. The therapeutic benefit of this mode of delivery is dependent on sufficient deposition of medication in the medium-sized and smaller airways, which is largely determined by a competent inhaler technique and holds true for inhalers of all designs and complexities11. Globally there are variations in prescribing practices for asthma and these have been ascribed to differences in the case mix of patients, socioeconomic factors, and availability of different inhaler and spacer devises locally 12. At the time of this study simple MDIs where the only type of devices officially marketed in Pakistan and majority of them were not CFC-free.
Guidelines for the management of asthma 13,14stress the use of therapy with inhaled corticosteroids for disease control. Treatment algorithms emphasize chronic maintenance therapy over acute episodic care and emphasize the need for its daily use in an effort to decrease morbidity and mortality rates 15. In our study, encouragingly a large majority (n=178, 88%) of the patients were prescribed an inhaled corticosteroids without any age or gender bias. However, only about two-thirds of these patients (n=101, 67%) reported using them regularly. In contrast to previous studies 3, a short-acting beta2 agonist inhaler (n=124, 60%) or its combination with a corticosteroid (n=14, 7%) was found to have been prescribed less frequently (table 3), which we believe is due to primarily to the easy availability of nebulizers and nebulized medication (without a physician’s prescription), which patients prefer to have as ‘backup’ to minimize emergency department visits and the ensuing costs. Alarmingly however, a larger proportion of the patients prescribed SABAs reported having been advised to use them between once a day to every 6 hourly (n=119, 86%), while only a small number (n=19, 14%) were found to be using them on an as-needed basis. The regular and continued use of this class of medications has in past raised concerns about an associated unrecognized decrease in their efficacy and a potential delay in seeking medical attention during periods of exacerbation 15. We believe that a possible reason for lower inhaled SABA prescription rates locally may be the easy availability of nebulizers and nebulized medication (without a physician’s prescription), which patients prefer to have as ‘backup’ to minimize emergency department visits and the ensuing costs.
As with any chronic disease, patient compliance is an important determinant of therapeutic success. Haynes and Sackett defined compliance more than three decades ago as “the extent to which a person’s behavior (in terms of taking medications, following diets, or executing lifestyle changes) coincides with medical or health advice.” 17 Creer et al18 divided factors that correlated with non-compliance into four categories: patient variables, interactions between physician or medical staff and patients or family, medication characteristics, and nature of asthma. Additionally, Cochrane19 described several patterns of noncompliance including taking only half of the medications at the prescribed times, taking regularly for a period and stopping, and skipping prescribed doses. In line with previously published data, more than a third of our patients (n=79, 39%) reported not being compliant with their medication in the preceding six weeks. Commonly reported reasons for non-compliance included improved symptom control and simply forgetting (figure 2). Noncompliance was found to be significantly higher in women (n=46, 58%) as compared to men (n=33, 41%). With respect to spacer use, more than a third of the patients admitted (n=37, 38%) not using it every time. Nearly half of these patients (n=16) also reported being non-compliant with both the medications and the spacer device. Therefore, the prescription of a spacer device to our cohort increased the total combined non-compliance rate to a worrisome 47% (n=95).
Previous studies have reported a high rate of incorrect inhaler technique with MDIs and dry-powder inhalers (DPIs) 8. In our study, 71% of the patients demonstrated an incorrect inhaler technique. Although no significant association was identified between the prevalence of poor technique and the variables age, gender, previous inhaler teaching and length of inhaler use (figure 1), the use of a spacer with the inhaler was found to be associated with a significantly lower rate of poor technique, which reinforces the role of spacers in patient populations such as ours, who may find it difficult to administer the inhaler correctly otherwise. Unfortunately though, only about two-thirds (n=60, 61%) of the patients admitted using the spacer every time they used the inhaler with approximately one fifth using it “occasionally” (n=19, 19%). Similar to earlier published data, incorrect slow inhalation technique was the most common mistake (n=49, 47%) made by patients using a simple MDI20. With the MDI+spacer combination, “holding breath at maximum inspiration” (n=42, 43%) was the most frequently identified error (figure 3).
Poor inhaler technique coupled with an inability to identify incorrect use can negatively impact patient compliance by causing them to incorrectly label their medications as ineffective and discontinuing treatment altogether 7. In our study, more than two-thirds (n=143, 70%) of the patients perceived their inhaler technique to be satisfactory, but nearly three fourth (n=100, 71%) of these also admitted to regularly observing fumes leaking around the inhaler during use. Interestingly, prior inhaler teaching showed no significant correlation with self-assessment of inhaler use or reporting of fumes escaping on use, implying poor retention of previous training and reinforcing the recommendations of previous studies that suggest regularly revisiting inhaler techniques with patients dependent on inhalers 7.
Our study has several limitations. Firstly, although the collection of data was standardized, some of it was based on self-reporting and thus a recall bias exists for such variables. In addition, if a more detailed review of the previous inhaler teaching had been performed, areas that needed further strengthening could have been better identified. Also, since the data collected was primarily pertaining to asthma and did not take into account co-morbid conditions, patient reporting may have been affected. For instance, given that a quarter of our patients were current or ex-smokers, a possibility of concomitant COPD exits, but we believe that this would not impact our overall conclusions. Lastly, this was a single center experience and may not be generalizable to other institutions.
Nearly half of our patients reported non-compliance to prescribed therapy. The most frequently reported reason for non-compliance was an improvement in symptoms. Age, gender or the number of inhalers prescribed did not predict non-compliance. ICS and SABA were the most frequently prescribed medications. Less than a third of the patients had been using the MDI correctly and a significantly larger proportion of patients was able to use MDI+spacer combination satisfactorily. Patient education and training with respect to compliance and inhaler technique need strengthening. Future studies aimed at evaluating the combined effect of health literacy, asthma knowledge/beliefs along with different inhaler training methods may help fill the gaps identified in this study.