Guideline Development

By the late 1980s, it was apparent that an epidemic of asthma had begun, particularly among children. This was emphasized by the dramatically increased mortality rates for asthma in New Zealand, which became the impetus for Australia and New Zealand to establish the first guidelines for the management of asthma in 1989. Shortly thereafter, consensus reports by expert panels on asthma assessment and management from Canada and from Britain were published as guidelines. This was followed shortly by the National Asthma Education and Prevention Program (NAEPP) Expert Panel Report from the USA in 1991. These early guidelines were based on expert opinion and provided consensus approaches to the diagnosis and management of asthma.

The first international consensus report was coordinated by the National Heart Lung and Blood Institute (NHLBI) and published by the National Institutes of Health (NIH) in 1992. Subsequently, the NHLBI, in cooperation with the World Health Organization, launched the Global Initiative for Asthma (GINA) in 1993. The first GINA report was published by the NIH in 1995 as a ‘Global Strategy for Asthma Management and Prevention.’ This was the first publication that aimed to provide a global approach to asthma and especially focussed on developing countries. As with previous guidelines, this was representative of expert opinion and consensus among those experts as to the best approach to asthma management.

Each of the initial guidelines primarily focussed on asthma in adults. Exemplary of the problems with developing a consensus around asthma in childhood was the situation at the initial Canadian Consensus Conference in 1989. At that workshop, pediatricians met as a separate subgroup to discuss the recommendations which were evolving within the expert group as a whole. Given the relative lack of research in children with asthma and a wide range of expert opinion on optimal approaches to treatment, the pediatricians were unable to develop any consensus focusing on the management of asthma in the pediatric population. However, over the next few years, pediatric-focussed guidelines began to emerge from national guideline committees with one of the earliest being from the British Thoracic Society in the mid-1990s. From that document, it became clear that separate categories and approaches to the diagnosis and management of asthma would be essential for school-aged children and for preschool children if the very best recommendations were to be developed. This was one of the first guidelines to bring focus to the issue of pediatric asthma, especially to recognition of the fact that there were few data upon which to build any recommended interventions for management of asthma in the young child.

Evidence-Based Medicine

The development of the initial asthma guidelines was driven by expert opinion and these were consensus based. However, by the early 1990s it was recognized that it would be important to define the quality of data and to begin to focus on evidence-based recommendations. Unfortunately, as evidenced by the very carefully structured British Thoracic Society guidelines, when an attempt was undertaken to rigorously define the quality of evidence for management of asthma in children, the best available evidence for pediatric asthma remained at the lowest level of quality (i.e. expert opinion generating a consensus). The levels of evidence used in a number of guidelines, including the GINA strategy and the NAEPP guidelines, are shown in Table 29-1 . This approach still underpins current GINA and NAEPP recommendations, including those recommendations for children.

Although the initial pediatric guideline recommendations reflected expert opinion, an important outcome was the recognition that there was a substantial lack of data to help guide recommendations for the management of children with asthma. As a result, a key component of the first Canadian Pediatric Asthma Guidelines published in 2005 was a section entitled ‘Implications for Research.’ This important component of a number of national guidelines was a stimulus toward promoting research in children and recognizes in particular that the development of the majority of cases of asthma begins in the preschool years ( Figure 29-1 ).

Annual incident rates per 100,000 person-years by sex and range for definite + probable asthma cases among Rochester residents 1964–1983.

(Data from Yunginger JW, Reed CE, O’Connell EJ, Melton LJ 3rd, O’Fallon WM, Silverstein MD. A community-based study of the epidemiology of asthma. Incidence rates, 1964–1983. Am Rev Respir Dis 1992;146(4):888–94.)

Increasing research in childhood asthma was important in facilitating development of the National Heart Lung and Blood Institute National Education Prevention Program Expert Panel Report 3: Guidelines for the diagnosis and management of asthma published in 2007. In that report, there was a strong focus on asthma in the preschool years (children 0–4 years of age) and in school-age children (5–11 years of age). Although there has been more research relating to asthma and the young child over the past decade, data to substantially update guidelines for children with asthma during the preschool years remain limited. In 2008, GINA approached the issue of asthma in the young child and established a panel of pediatric asthma experts to focus on the issues of concern in these young, preschool children. In 2009, GINA published the ‘Global Strategy for Asthma Management and Prevention in Children 5 Years and Younger’ with an emphasis on challenges in the diagnosis and management of asthma in these preschool children. Recommendations in the report were based on the best evidence available. However, because of the relative paucity of randomized or even observational clinical trials in this population, many recommendations remained at level D, i.e. panel consensus judgment. The expert opinion approach based on available data and consensus opinion published by GINA provides a strategy for the development of guidelines by local and national organizations which are pertinent to their specific population characteristics, available healthcare resources and local or national environments.

Guidelines are commonly developed by a panel of experts where the intent is to produce recommendations based on the best evidence available. Increasingly, there are pressures to produce recommendations based on the quality of a body of evidence assessed independently by a multidisciplinary team. Increasing adherence and focus to better define the quality of evidence remains a problem where there is a lack of substantive data. This is most apparent in the assessment and management of asthma in children during the preschool years. We require substantially more research in this area, both more structured randomized controlled trials and improved observational studies. Until such data are more abundant, guideline recommendations for the young child will continue to rest on expert panels with the appropriate clinical experience to provide the best possible recommendations for consideration in the development of local and national guidelines.