A strategy for measuring health outcomes and evaluating impacts of interventions on asthma and COPD--common CRD in GARD countries

The use of standardized, evidence-based indicators is essential for the assessment of risk factors for chronic respiratory diseases (CRDs) and their overall burden, as well as the evaluation of clinical and public health interventions across countries (1). The collection and reporting of accurate and timely health information, including diseasespecific measures of morbidity and mortality, helps to direct the allocation of health care resources and optimizes decision making in health policy. International comparisons of CRD burden are primarily drawn from existing population-based studies. For example, the International Study of Asthma and Allergy in Childhood (ISAAC) has provided information on the prevalence of asthma symptoms in children using samples from 56 countries (2). The European Community Respiratory Health Survey is another example of the standardized collection of information from multiple countries, providing abundant information on morbidity, risk factors and the cost of CRDs (3). There are also the PLATINO studies (4) and the BOLD studies (5), which have examined the burden of chronic obstructive pulmonary disease (COPD) across Latin America and other continents, respectively. Existing CRD work by the World Health Organization (WHO) includes a report of findings from the World Health Survey (6), iterations of the Global Burden of Diseases reports (7), and the GARD Basket (8). The use of common measures for the assessment of modifiable risk factors and health outcomes in research and practice allows for the comparison of the effectiveness of different interventions. Unfortunately, the availability, applicability, interpretation and usefulness of some indicators have not been widely assessed or demonstrated, suggesting an urgent need for a common/uniform strategy to assess the impact of health initiatives and to measure the overall global burden of CRDs. Therefore, the objective of this paper is to recommend a strategy to support GARD countries to conduct impact assessments and estimate the burden of CRDs using evidenced-based, validated CRD indicators and a streamlined process to statistical reporting. Our recommended strategy will form a supporting assessment tool to GARD countries that are implementing individual and community-based interventions that support the Action Plan of GARD (9) and the 2013-2020 Action Plan of The Global Strategy for Prevention and Control of Noncommunicable Diseases (10). It should be noted that, whereas CRDs are a broad category encompassing many conditions, recommending a strategy that incorporates all CRDs is beyond the scope of this paper. Thus, from this point forward we focus more specifically on asthma and COPD, common respiratory conditions for which there are existing evaluation frameworks in support of this work. The proposed strategy presented herein is meant to illustrate the evaluation process and may serve as a template that can be modified, as appropriate, for the evaluation of other CRDs in the future.