6.2 Medications used to treat asthma
Introduction [back to top]
Drug therapy is the mainstay of asthma management. Broadly speaking, there are three ways in which medications are used in the treatment of asthma:
The most commonly used class of medications for relief of symptoms are short-acting beta-agonists (salbutamol and terbutaline). However, rapid-onset, long-acting beta-agonist drugs (formoterol; see Box 6.1) (O’Byrne et al. 2005) and short-acting anti-cholinergic drugs (ipratropium) can also be used for this purpose in some management plans.
There is evidence from systematic reviews that inhaled corticosteroids (beclomethasone, budesonide and fluticasone) are highly effective for the second purpose, to minimise symptoms and prevent exacerbations (Adams et al. 2003, 2004a, 2005). Recent analyses of data from clinical trials have demonstrated that most people with asthma can be well controlled with relatively low doses of inhaled corticosteroids, resulting in a low risk of adverse effects (Powell & Gibson 2003). The addition of long-acting beta-agonists to inhaled corticosteroids, now available in combined formulations (salmeterol+fluticasone and formoterol+budesonide), allows equivalent or greater effectiveness in disease control with lower doses of inhaled corticosteroids (Greening et al. 1994). Leukotriene receptor antagonists (montelukast and zafirlukast) are also used for disease control, though they are less effective than inhaled corticosteroids (Ng et al. 2004). Cromones (cromoglycate and nedocromil) have been traditionally used for the prevention of asthma exacerbations in children but evidence for their effectiveness for this purpose is generally lacking.
Oral corticosteroids have long been the mainstay of treatment for exacerbations of asthma. The role of intermittent use of inhaled corticosteroids or short-term increases in the maintenance or usual dose of inhaled corticosteroids remains uncertain.
Guidelines for the management of asthma (GINA 2006; NAC 2006) generally recommend a stepwise approach to management, aiming to optimise asthma control, with intermittent use of medications to relieve symptoms when they occur, regular (daily or twice daily) use of medications to control the disease and prevent symptoms and exacerbations, and occasional short courses of oral corticosteroids to treat disease exacerbations. Different classes of medications are used for each of these purposes, as outlined above. However, recent evidence has demonstrated that an alternative approach, in which a combined rapid-onset long-acting bronchodilator and inhaled corticosteroid (formoterol+budesonide) is used twice daily to control the disease and also as required for the relief of symptoms (O’Byrne et al. 2005), is also effective in achieving good disease control.
6.2.1 Monitoring use [back to top]
Since appropriate use of medications for asthma improves disease outcomes, disparities in the use of medication are almost certainly relevant to disparities in outcomes of asthma. Under-use of medication to control the disease does occur in poor areas in the United States of America (USA) and Great Britain. Furthermore, adherence to use of various types of medication, including inhaled corticosteroids, is also lower among those with lower socioeconomic status (Apter et al. 1998; Wamala et al. 2007) and in African Americans compared to others in the USA (Bosworth et al. 2006; Charles et al. 2003a).
A central issue in determining the appropriateness of use of medications for asthma is the underlying severity of asthma and the level of asthma control at the time the medications were prescribed. However, it is usually not possible to determine from survey data or prescription data whether the level of treatment that has been prescribed or dispensed is appropriate for the level of disease severity or control (Khan et al. 2003). In the absence of information on disease severity and control, information on the use of medications must be interpreted with caution.
In this chapter, we review data on use of medications for the treatment of asthma in Australia, focusing in particular on medications used to control the disease, principally inhaled corticosteroids. Data on other principal classes of medications are also presented. Various sources of data have been used for this purpose.
6.2.2 Sources of data [back to top]
Pharmaceutical Benefits Scheme (PBS) data
Information on reimbursements for the purchase of prescription medications is available from the PBS and the Repatriation Pharmaceutical Benefits Scheme (RPBS) databases. An important limitation of these data is that the databases only include records for prescriptions that were subsidised by the PBS and RPBS. The PBS currently subsidises the cost of approximately 80% of prescription medications dispensed in Australia (DoHA 2006). However, even for these items that are covered by the PBS or RPBS, subsidies are only paid, and hence recorded in the database, where the cost of the medication is more than the copayment amount. The copayment amount is the amount the consumer pays. The government subsidises any additional amount above the copayment. The copayment amount differs substantially between general patients and those who hold government health-care concession cards. For the former, the copayment amount ranged from $22.40 in 2002 to $30.70 in 2007, whereas for people holding concession cards, the copayment amount ranged from $3.60 in 2002 to $4.90 in 2007. This means that many medications are far cheaper to those with concession cards. The implications of this limitation and the way in which we have dealt with it in this report are described below.
All long-acting beta-agonist preparations (except Oxis 6 Turbuhaler in 2005 and 2006; see Appendix 1, Table A1.7) and all combined long-acting beta-agonist and inhaled corticosteroid preparations are at a price higher than the PBS copayment amount for general patients. Hence, the PBS database contains a complete record of prescriptions in Australia for these medication classes.
Most inhaled corticosteroid preparations cost more than the PBS copayment amount for those without a concession card but some formulations cost less and, hence, were not captured on the PBS database (see Appendix 1, Table A1.7). Since the PBS schedule changes frequently throughout the year, the prescriptions covered by the scheme can vary within a year and from year to year.
Short-acting beta-agonists and oral corticosteroids cost less than the PBS copayment amount and are only subsidised by the PBS when the patient is a concession card holder. For this reason, our PBS analysis of short-acting beta-agonist and oral corticosteroid prescriptions has been limited to those dispensed to concession card holders.
Short-acting beta-agonists are also available ‘over the counter’, that is, without a prescription. However, the over-the-counter cost is greater than the copayment for a concession card holder who uses a prescription, which means there is a financial incentive for concession card holders to purchase short-acting beta-agonists with a doctor’s prescription. Therefore, it is assumed that most, though not all, short-acting beta-agonists dispensed to people with a concession card are supplied with a prescription and recorded on the PBS database.The PBS database, which was designed for administrative purposes, has included patient Medicare numbers with all prescription details since 2002. Use of the Medicare number has allowed us to anonymously identify prescriptions for the same individuals within the PBS data and also to link information on age, sex and home postcode using an encrypted Medicare patient identification number. In this way, it is ensured that patient confidentiality is protected.
IMS Health data
Information on the wholesale supply of medications in the community is available from IMS Health, a commercial market information company. IMS Health collects data from all pharmaceutical wholesalers about the sale of both prescription and non-prescription medications to the hospital and community sectors. Since these are wholesale supply data, they do not include any information about the individuals who purchased the medications. See Appendix 1, Section A1.8, for more details about these data sources.
Unfortunately, data from the PBS and IMS Health do not contain information on the reason for which the drug was prescribed. The medications that are used for asthma are also used for the treatment of some other respiratory illnesses, in particular, chronic obstructive pulmonary disease (COPD) among older people and wheezy bronchitis in young children. For this reason, medication use within the subgroup of people aged 5–34 years is described separately in this chapter. In this age group, COPD is very uncommon and wheezy bronchitis is a relatively uncommon diagnosis and, therefore, the medications were more likely to have been used for asthma.
Health surveys, including the ABS NHS, are the best source of information about actual use of medication by people with asthma and we have included some information from the 2004–05 NHS. Information about how asthma medications are prescribed in general practice is provided in Section 5.1.
In the following sections, we describe the rate of medication use for asthma and other respiratory conditions in the community as a whole and assess variation by age group, sex, socioeconomic status and remoteness of residence.
6.2.3 Time trends in the supply of medications for asthma and other respiratory disorders [back to top]
Figure 6.5 shows the trend in the supply of various medications from IMS Health (wholesalers) as well as the trend in the PBS data (reimbursement of prescriptions) for medications commonly used to treat asthma since the mid-1990s. The trend data are expressed in units of defined daily doses (DDDs) per 1,000 population per day. This unit of measurement represents a standardised measure of medication dosage, allowing data for different members of the same class to be combined and various classes to be compared, using a common currency. See Appendix 1, Section A1.8.3, for more details of these calculations.
Short-acting beta-agonists, mainly salbutamol and terbutaline, remain the most commonly supplied class of medications among those used to treat respiratory disorders in Australia (Figure 6.5a). This class of medication is commonly dispensed over the counter, that is, without a prescription. Therefore, we have also incorporated information from the Pharmacy Guild Survey in our estimation of reimbursed prescriptions for short-acting beta-agonists (Figure 6.5b) which takes into account over-the-counter purchases. According to this survey, approximately 27–30% of short-acting beta-agonists were purchased over-the-counter between 2002 and 2006 (DoHA 2007b). Short-acting beta-agonists and anti-cholinergics are also commonly used in patients hospitalised with respiratory illness, where they are dispensed by hospital pharmacies. In this case, usage would be recorded in the IMS Health data but not in the PBS and Pharmacy Guild Survey data. Apart from the difference observed in the case of short-acting beta-agonists, the IMS Health data on wholesale supply and combined PBS and Pharmacy Guild Survey data on reimbursed prescriptions agree very closely (Figure 6.5).
Supply of short-acting beta-agonists has been decreasing since 1999 and, more recently, use of the short-acting anti-cholinergic ipratropium bromide has also been declining. The latter trend has probably been accelerated by the introduction of tiotropium bromide, a long-acting anti-cholinergic medication that is mainly recommended for use by patients with COPD.
The annual total usage of inhaled corticosteroids has been relatively stable over a long period of time. There was a small increase in supply between 1999 and 2002, but since then there has been a small decrease back to pre-1999 levels (Figure 6.5a).
Long-acting beta-agonists first became eligible for reimbursement under the PBS in 2000. Since that year, there has been a rapid increase in the use of this class of medications (Figure 6.5b).
The use of other medications for asthma and other respiratory disorders, cromones (cromoglycate and nedocromil) and theophylline, was low and decreased during 1995–2006. Reimbursement for prescriptions for leukotriene receptor antagonists has only recently been introduced and only children are eligible. The overall usage of this class of medications remains low relative to other respiratory medications.
6.2.4 Time trends in the supply of medications for asthma and other respiratory disorders [back to top]
In 2004–05, almost 56% of people with asthma reported using medication for their condition in the last 2 weeks (NHS data). The proportion of people with asthma who used medication increased with age (p trend < 0.0001). The lowest reported use was among children aged 5–14 years (45%) and the highest was among those aged 65 years and over (75%).
Among school-entry children in the Australian Capital Territory, 94% of those with parent-reported asthma had used at least one asthma medication in the preceding year (Phillips et al. 2007).
Inhaled corticosteroids are used to reduce airway inflammation; a key feature of asthma. For patients with asthma, this results in better control of symptoms and disease exacerbations. They are most effective when used on a regular basis, either daily or twice daily. Regular use of inhaled corticosteroids is the recommended treatment in people with persistent asthma.
In 2006, there were 23 standard defined daily doses (DDDs) of inhaled corticosteroids supplied per 1,000 persons per day. This represented a continuation of a downward trend in this measure of utilisation from a peak in 2002 (28 DDDs per 1,000) (Figure 6.5).
Among people with current asthma aged 5 years and over in 2004–05, 18.5% reported having used inhaled corticosteroids in the previous 2 weeks (ACAM 2007a). In the subgroup who reported using short-acting beta-agonists in the previous 2 weeks, indicating that they were likely to have experienced symptoms of asthma during that time, only 28% had also used inhaled corticosteroids during this period. Hence, there is evidence that use of inhaled corticosteroids for control of symptomatic asthma is sub-optimal in the community.
The frequency of medication use among children with asthma had remained stable between 2000 and 2005 in the Australian Capital Territory and 53% of all children with asthma that were taking inhaled corticosteroids, mast cell stabilisers or montelukast were using them at least 4 days per week during this time (Phillips et al. 2007).
In 2006, prescription data from the PBS showed that the use of inhaled corticosteroids increased with age (Table 6.2). This is consistent with the trends seen in the use of other classes of medication used in the treatment of asthma and may reflect the changing nature of obstructive lung disease from childhood to older adult life. There were no important differences in rates of use of this class of medication with levels of socioeconomic disadvantage. However, government health-care concession card holders were more likely to be dispensed inhaled corticosteroids (11%) than those without a concession card (4%). The cost of inhaled corticosteroids is approximately six times greater for individuals who do not have a concession card. Therefore, it appears that cost is an important barrier to use of inhaled corticosteroids.
Combined long-acting beta-agonist and inhaled corticosteroid formulations
Inhalation devices that combined long-acting beta-agonists and corticosteroids in the same unit were introduced onto the Australian market in 2000. In subsequent years, the proportion of all inhaled corticosteroids that were supplied by wholesalers in combination with long-acting beta-agonists steadily increased. Two years after their introduction onto the Australian market, combined therapy represented 47% of all wholesale supplied inhaled corticosteroid therapy and, by 2006, the market share had risen to 74% (Figure 6.6).
In the Australian population, use of inhaled corticosteroids and long-acting beta-agonists in combination formulations increased with age. Among those aged 0–4 years, only 1.4% were dispensed this type of combined therapy while 8.8% of those aged 65 years and over were dispensed this class of medication. In the population as a whole, there tended to be slightly higher rates of use among people living in areas of greater socioeconomic disadvantage. However, this was not observed when the analysis was limited to people aged 5–34 years. People living in more remote areas had lower rates of use. There were much higher rates dispensed to government health-care concession card holders than to those without a concession card.
Number of inhaled corticosteroid prescriptions
In children, intermittent asthma is much more common than persistent asthma. Hence, inhaled corticosteroids are generally not required for the treatment of asthma in children, particularly in young children. For this reason, we describe the use of this class of medications separately for adults and children.
Adults. Between 2003 and 2006, the use of any inhaled corticosteroids, as indicated by the number of prescriptions dispensed for this class of medication during that time, decreased among people aged 15–64 years, particularly since 2005 (Figure 6.7). This is consistent with the overall decline in supply over this period, as described above. This may be partly attributed to the large (24%) increase in the copayment cost in January 2005. Studies from Western Australia have shown that dispensing of combined asthma medications decreased following the rise in copayment cost at that time (Hynd et al. 2008).
In 2006, 5.7% of persons aged 15 years and over had at least one prescription for inhaled corticosteroids. The use of inhaled corticosteroids increased with age. In 2006, 3.6% of those aged 15–34 years, 5.3% of those aged 35–64 years and 11.6% of those aged 65 years and over had at least one prescription for inhaled corticosteroids. Among persons aged 15–34 years, more than half of those dispensed any inhaled corticosteroids only had one prescription for this class of medication in any one year, compared to 36–39% of those aged 35–64 years (Figure 6.7).
People aged 65 years and over had the highest prevalence of having inhaled corticosteroids dispensed and the highest proportion of frequent users. Approximately 30% of people in this older age group who had a prescription for inhaled corticosteroids had seven or more prescriptions. Furthermore, 5–6% had 13 or more prescriptions in any given year (that is, more than one prescription per month). In contrast, only 8–9% of people aged 15–34 years and 18–19% of those aged 35–64 years had seven or more inhaled corticosteroid prescriptions between 2003 and 2006. This is likely to be the minimum rate of prescription consistent with regular use.
Children. Thirty-one to 39% of children with parent-reported asthma, who were beginning school in the Australian Capital Territory during the period 2000 to 2005, were using inhaled corticosteroids at that time. There was no trend in usage over this period (Phillips et al. 2007). However, data from the PBS demonstrates that overall, between 2003 and 2006, the use of inhaled corticosteroids decreased among children aged 0–14 years, particularly since 2005 (Figure 6.8). This may reflect a decline in the prevalence of asthma in children over this period.
In 2006, 2.4% of children aged 0–4 years and 4.1% of children aged 5–14 years were dispensed at least one prescription of inhaled corticosteroid. In 2006, the overall proportion of children aged 0–14 years who were dispensed any inhaled corticosteroids was 3.6%. More than half of the children dispensed inhaled corticosteroids were dispensed only one prescription in any given year between 2003 and 2006.
Overall, both the prevalence and the frequency of use of inhaled corticosteroids were much greater in people aged 15 years and over than in children. This is to be expected given the differences in the patterns of disease observed.
Potency of inhaled corticosteroids
Data on the supply of pharmaceuticals demonstrate that both the total number of doses and the proportion of doses that are the highest potency formulation of inhaled corticosteroids have declined substantially during 2006 (Figure 6.9). However, less potent formulations still represent a minority of those supplied. A similar trend is observed in examining dispensed prescriptions. The majority of prescriptions for inhaled corticosteroids were for the most potent formulations of this class of medication (Figure 6.10).
Adults. Overall, among persons aged 15 years and over, 54.8% of prescriptions for inhaled corticosteroids were in the most potent category, 42.1% were of intermediate potency and only 3.1% were classified as being in the least potent category.
A higher proportion of older Australians were prescribed inhaled corticosteroids of the most potent formulations compared to young adults and those aged 35–64 years (Figure 6.11). Those aged 65 years and over were also more likely to have 13 or more prescriptions for intermediate and most potent formulations of this class of medication in 2006 than younger adults.
Children. Among children (those aged less than 15 years), 50.6% of prescriptions for inhaled corticosteroids were in the least potent category, 40.2% were of intermediate potency and only 9.3% were classified as being in the most potent category.
There was a much higher proportion of children aged 5–14 years who had prescriptions for intermediate and most potent formulations of inhaled corticosteroids compared to children aged 0–4 years (Figure 6.12). The frequency of use of these more potent formulations was also higher in older children compared to younger children.
Short-acting bronchodilators are commonly referred to as ‘relievers’ due to their mode of use by patients with asthma. Short-acting beta-agonists (salbutamol and terbutaline) are the most commonly used class of short-acting bronchodilators. They are very effective in providing rapid relief of acute asthma symptoms and, since they can be purchased without a prescription, are readily accessible in Australia (ACAM 2005). The duration of action of short-acting beta-agonists is typically 4–6 hours (Lotvall 2002).
It is recommended that short-acting beta-agonists are used on an as-needed basis for short-term relief of symptoms (NAC 2006). Short-acting anticholinergics (ipratropium) and rapid-onset, long-acting beta-agonists (formoterol; see Box 6.1) may also be used as ’relievers’.
Overall, 12.3% of all adults holding a government health-care concession card had at least one PBS-subsidised prescription for short-acting beta-agonists during 2006. In 2004–05, 47.5% of surveyed people with current asthma who were aged 5 years and over reported using short-acting beta-agonists in the last 2 weeks (NHS confidentialised unit record files—CURFs). Furthermore, among people attending their GP for management of asthma, 94% had used a short-acting beta-agonists in the previous 12 months including 14% who reported using this medication twice daily (13.8%) (AIHW: Britt & Miller 2007, SAND abstract 104). Hence, use of short-acting bronchodilators is very common among people with asthma and related conditions.
Some children who use salbutamol do not have a diagnosis of asthma. Among children beginning school in the Australian Capital Territory who were taking salbutamol, 19% did not have a diagnosis of asthma in 2000 and this proportion had increased to 35% in 2005 (Phillips et al. 2007). It is possible that this increase reflects changes in diagnostic labelling.
Route of administration of bronchodilators
Short-acting bronchodilators are available in oral formulations as well as inhaled formulation. However, oral formulations are associated with reduced efficacy and more side effects and are not recommended for use in patients with asthma. In fact, nearly all short-acting beta-agonist and anti-cholinergic bronchodilator medication is administered by inhalation (Figure 6.13). The most popular devices supplied were metered dose inhalers, or ‘puffers’. Between 1996 and 2000, approximately one-quarter of the supply of this class of medication was in the form used for nebulised delivery. This proportion has gradually declined and in 2006 only 15% was supplied in the form of nebuliser solution. The decrease in the use of nebulised bronchodilators is in accordance with current evidence and recommendations (Cates 1999).Figure 6.13: Delivery devices supplied by wholesalers for the administration of short-acting beta-agonist and anticholinergic medication, by defined daily dose per 1,000 persons per day, 1996–2006
Sociodemographic distribution of use
The prevalence of use of short-acting beta-agonists by people with current asthma in 2004–05 was highest among young adults aged 15–34 years (49.0% used this medication class in the previous 2 weeks) and older adults (49.7%) but was also common among children (36.4%) (NHS CURFs).Prescription of short-acting beta-agonists was slightly more common in females (13.2%) than males (11%) (PBS data for concession card holders, Table 6.3). Use of this class of medications increased with age. Among those aged 65 years and over, 13.5% were dispensed this class of medication compared to only 10% among those aged 15–34 years. Among people aged 15 years and over, those residing in inner regional areas of Australia had a higher proportion of short-acting beta-agonist prescriptions dispensed than those living in major cities or remote areas of Australia (p < 0.0001).
The need to limit the analysis of short-acting beta-agonist prescriptions data to concession card holders meant it was not possible to judge the impact of socioeconomic status, since concession card holders already represent a more socioeconomically disadvantaged subgroup. Studies elsewhere have explored this. In Canada, Lynd and colleagues (2004) found that greater levels of socioeconomic disadvantage were associated with higher levels of use of short-acting beta-agonists, even when controlling for level of severity of asthma.
Generally, high rates of use of short-acting beta-agonists are an indicator of poor asthma control. Campaigns that focus on the subgroup of people with asthma who are high users of short-acting beta-agonists may lead to gains in a range of asthma outcomes.
Long-acting beta-agonists (salmeterol and formoterol), which were introduced into clinical use in Australia in 1999, provide approximately 12–24 hours bronchodilatation (Lotvall 2002). Current national (NAC 2006) and international (GINA 2006) guidelines for the management of asthma recommend that adults with asthma that is not adequately controlled on moderate doses of inhaled corticosteroids alone use long-acting beta-agonists in conjunction with inhaled corticosteroids on a regular basis.
Overall, 4.3% of the population used this class of medications in 2006. Use was greater among females (4.7%) and those aged 65 years and over (9.3%) (Table 6.4).
There was little variation in the proportion of users according to socioeconomic status and remoteness of residence. However, there was a higher proportion of government health concession card holders that were dispensed this class of medication compared to those without concession cards. The same trends were seen among persons aged 5–34 years (Table 6.4).
There is evidence that long-acting beta-agonists are less effective in children than in adults and their use is not recommended except in children with asthma that is poorly controlled despite other therapy (Bisgaard & Szefler 2006; Sorkness et al. 2007). Hence, we have described the utilisation of this class of medications separately for adults and children.
Long-acting beta-agonist prescriptions among adults
There has been an increase in the proportion of adults dispensed long-acting beta-agonists between 2003 and 2006 (Figure 6.14). In 2006, 4.7% of all persons aged 15 years and over were dispensed at least one prescription for long-acting beta-agonists.
The proportion of adults using four or more prescriptions per year increased with age (Figure 6.14). In 2006, 0.8% of adults aged 15–34 years had four or more prescriptions for this class of asthma medication compared to 1.8% of adults aged 35–64 years and 5.5% of those aged 65 years and over. Furthermore, during the same year, 0.3% of people aged 15–34 years had seven or more prescriptions for long-acting beta-agonists compared to 0.9% of adults aged 35–64 years and 3.3% of those aged 65 years and over.
Long-acting beta-agonist prescriptions among children
The proportion of children dispensed long-acting beta-agonists also increased between 2003 and 2005 (Figure 6.15). Between 2005 and 2006, there was a decrease in the rate of prescriptions for this class of medication among children.In 2006, 2.5% of all children aged 0–14 years were dispensed at least one prescription for long-acting beta-agonists. Usage was much lower in younger children. In contrast to adults, approximately half of the children prescribed long-acting beta-agonists were dispensed only one prescription in any given year (Figure 6.15). Very few children averaged one or more prescriptions for long-acting beta-agonists per month.
During episodes of more severe asthma (known as ’exacerbations’), oral corticosteroids may be used to gain control of the disease. A very small number of people with asthma need long-term treatment with oral corticosteroids to control their disease.
Among concession card holders who had a prescription for any asthma medication in 2006, 3.4% were dispensed oral corticosteroids (Table 6.5). The use of oral corticosteroids increased with age, with 1.5% of those aged 15–34 years compared to 4.6% of those aged 65 years and over being dispensed oral corticosteroids in 2006.
The use of oral corticosteroids by people being treated for asthma increased with age but has remained stable over the period 2003–2006 (PBS data for concession card holders who had been dispensed at least one other medication for asthma, Figure 6.16). In 2006, 1.5%, 3.1% and 4.6% of people with a concession card aged 15–34 years, 35–64 years and 65 years and over, respectively, were dispensed one or more prescription for oral corticosteroids. Most adults who were dispensed oral corticosteroids filled only one prescription for this class of medication in any one year. Furthermore, the proportion of adults with multiple prescriptions for oral corticosteroids increased with age.
Summary [back to top]
The most important change in the nature of the pharmacological treatment for asthma over the last 5 or 6 years has been the gradual increase in use of long-acting beta-agonists in combination with inhaled corticosteroids. This has been accompanied by a reduction in the use of short-acting beta-agonists over this period, possibly indicating a trend to improved levels of control of the disease.
However, there are important age-related differences in treatment for asthma. The use of almost all medications for asthma increases with age. The pattern of use of asthma therapies is quite different in children compared with adults. Use of inhaled corticosteroids is less common in children than in adults with asthma. Most children using inhaled corticosteroids are only dispensed one prescription per year. Furthermore, the majority of inhaled corticosteroids prescribed to children are among the less potent formulations and combination with long-acting beta-agonists is relatively uncommon in children, particularly in young children. In the last year of data (2006), there was a reduction in the use of inhaled corticosteroids.
Among adults, the majority of inhaled corticosteroids are prescribed in combination with long-acting beta-agonists. Clinical trials have shown that this combination should allow equivalent effectiveness for controlling asthma with a lower dose of inhaled corticosteroids. There is some evidence that, in the most recent year of data (2006), there was a reduction in the prescription of the most potent formulations of inhaled corticosteroids. It is clear that intermittent use of inhaled corticosteroids is the most common mode of use in adults, as well as children, despite treatment guidelines recommending regular use in people with persistent asthma.
The explanation for the reduction in both supply of, and prevalence of use of, inhaled corticosteroids in the last 3 or 4 years cannot be directly deduced from the available data. Possible explanations include (a) steroid sparing effects of combination with long-acting beta-agonist; (b) a reduction in the prevalence or severity of asthma in the community; (c) greater recognition of intermittent asthma, particularly in children, for whom regular inhaled corticosteroids may not be indicated; and (d) less appropriate use of inhaled corticosteroids due to the cost of medications and other barriers to their effective use.
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