A Review of the GOLD Guidelines for the Diagnosis and Treatment of Patients With COPD

Abstract and Introduction

Abstract

Chronic obstructive pulmonary disease (COPD) is a leading cause of death in the USA, and represents a major health, social and economic burden. COPD is underdiagnosed and often misdiagnosed, which likely contributes to the continuing increases in the prevalence, morbidity and mortality associated with this disease. This is unfortunate because whereas COPD cannot be cured, it can be treated effectively, particularly during the earlier stages of the disease. Evidence-based guidelines, developed to assist in the prevention, diagnosis and management of COPD, are available to healthcare professionals interested in learning more about COPD. These guidelines are updated and revised on a regular basis to reflect recent advances in our understanding of the pathophysiology of and treatments available for COPD. Nevertheless, primary-care physicians have reported a lack of awareness of the fundamental concepts underpinning the optimal treatment and management of COPD presented in the guidelines. Thus, the objective of this article is to summarise key physiologic, diagnostic and management concepts provided in the most recent update of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines, which were published in November 2006.

Introduction

Chronic obstructive pulmonary disease (COPD) is characterised by airflow limitation in the lungs that is usually partially reversible and generally progressive.^[1] The definition of the disease has changed as our understanding of the underlying pathophysiology and management has increased and evolved. As defined in the Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Pulmonary Disease,^[1] which was issued in 2006 as the revised consensus report of the Global Initiative for Chronic Obstructive Lung Disease (GOLD), 'COPD is a preventable and treatable disease with some significant extrapulmonary effects that may contribute to the severity in individual patients. Its pulmonary component is characterised by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lung to noxious particles and gases'.

Chronic obstructive pulmonary disease is currently the fourth leading cause of death in the USA and is projected to be third by the year 2020.^[1,2] It is estimated that both morbidity and mortality will continue to increase.^[1] Approximately 12 million adults in the USA have been diagnosed with COPD, whereas an estimated 12 million adults have undiagnosed COPD.^[2] In 2003, COPD was responsible for 15.4 million physician office visits^[2] and in 2007, the estimated total annual costs will exceed $42.6 billion ($26.7 billion for direct healthcare costs).^[2] These costs actually may underestimate the real total costs because they do not take into account costs resulting from undiagnosed disease and comorbidities^[3] or secondary costs incurred by family members and caregivers of patients with COPD.^[1] COPD thus represents a major health, economic and social burden. This may be due in part to lack of awareness with regard to fundamental diagnostic procedures and proper disease management.^[4]

Evidence-based guidelines for the treatment and management of COPD have been developed through collaborations of leading experts in COPD and organisations, including the National Heart, Lung and Blood Institute and the World Health Organization. The GOLD guidelines are the result of such efforts. These guidelines were first released in 2001 for the purposes of increasing awareness of COPD; improving the ability to diagnose, prevent and manage COPD; decreasing the morbidity and mortality associated with the disease; and identifying areas of interest for future research. A comprehensively updated version was issued in November 2006,^[1] and the information and recommendations in this review are largely based on these revised guidelines. An executive summary of the GOLD guidelines was published in 2007.^[5] In addition, COPD guidelines have been published by professional societies, including the American Thoracic Society,^[6] the European Respiratory Society,^[6] the Canadian Thoracic Society^[7] and the National Institute for Clinical Excellence,^[8] each with a similar purpose: to improve the prevention, diagnosis, and management of COPD.

Despite the availability of these published evidence-based guidelines, survey results have shown that awareness and understanding of COPD, particularly among primary-care physicians (PCPs), is lacking with regard to key COPD guideline criteria, recommendations and implementation of treatment strategies.^[4,9] Results of a study by Tsagaraki et al.^[9] of adherence to international COPD guideline recommendations by lung specialists vs. PCPs seem to reflect the situation. The investigators found that although international guidelines that outline strategies for the successful treatment of COPD are readily available and assessable, lung specialists tend to adhere to management guidelines, whereas PCPs do not. This likely contributes to underdiagnosis and undertreatment of COPD, especially in the early stages of the disease when intervention can be most beneficial.^[4,10] In a study conducted to evaluate PCPs' knowledge of COPD guidelines, Rutschmann et al.^[4] similarly found that the clinical practices used by PCPs in the management of patients with COPD do not match the basic recommendations of the COPD guidelines, especially with respect to preventive measures. These findings are especially important because patients with undiagnosed COPD are likely to be seen first by PCPs.^[11,12] Furthermore, PCPs are responsible for approximately 70% of the care of patients with COPD.^[13] Surprisingly, a US study which examined 20 different aspects of guideline-defined care for COPD revealed that patients received 60% of recommended care for exacerbations, but only 46% for routine care. The lowest scoring aspect was ordered laboratory/radiology tests at 40% of recommended care.^[14] Therefore, the purpose of this review is to briefly summarise the major findings and recommendations included in the 2006 GOLD guidelines, and to illustrate that compliance with treatment and management recommendations in the these guidelines can result in improved clinical outcomes for millions of patients.