**3. Chronic obstructive pulmonary disease: Epidemiological data**

Chronic obstructive pulmonary disease is a leading cause of mortality and morbidity worldwide, affecting approximately 210 million people and leading to 3 million deaths annually (WHO, 2011).

The prevalence and morbidity data greatly understimate the total burden of COPD because the disease is usually not diagnosed until it is clinically apparent and moderately advanced. Furthermore, population-based estimates of COPD prevalence by region are problematic since the disease is progressive, measurement tools and definitions still vary among studies, and implementation of spirometry is often not feasible in developing regions (Lopez et al., 2006a).

A recent systematic review and meta-analysis on global burden of COPD reported a prevalence of physiologically defined COPD of 9-10% in adults (Halbert et al., 2006). These

Population ageing is progressing rapidly in many industrialized countries. For the world as a whole, the elderly will grow from 6.9% of the population in 2000 to a projected 19.3% in

Population ageing is a great challenge for the health care systems. As nations age, the prevalence of disability, frailty, and chronic diseases (Alzheimer's disease, cancer, cardiovascular and cerebrovascular diseases, COPD, etc.) is expected to increase

Frailty is gaining attention in many fields because it increases the risk of hospitalization, falls, mortality and institutionalization. Geriatricians, gerontologists, and social scientists study frailty to better understand its impacts on health, individuals, and society. Frailty has been considered synonymous of disability or co-morbidity, but it is recognized that it is a biological syndrome identified by decreased reserves in multiple organ systems. The incidence of frailty increases with age, reaching more than 32% in those older than 90 years (Fried et al., 2001). Frailty can be a primary diagnosis, when the state is not associated directly with a specific disease, or a secondary diagnosis when the syndrome occur as a result of an acute event or the end stage of many chronic conditions, including severe congestive heart failure, stroke, chronic inflammatory diseases and dementia. The hospital, which is the "gold standard" for the delivery of acute medical care, is not an ideal environment for frail elderly patients. A new functional impairment and iatrogenic events such as nosocomial infections, pressure sores, falls and delirium are common during

Chronic obstructive pulmonary disease is a major cause of chronic morbidity and mortality. Patients with COPD usually have progressive airflow obstruction that is not fully reversible, which leads to a history of progressive, worsening breathlessness that can impact on daily activities and health-related quality of life. Winter outbreaks of COPD exacerbations, mostly occurring in elderly people with concurrent chronic co-morbidities, often generate dramatic increases in hospital emergency room admission. Such admissions have increased substantially over the past decade, comprising a significant proportion of all hospital admissions, and are associated with a high rate of readmission contributing to the high costs

Chronic obstructive pulmonary disease is a leading cause of mortality and morbidity worldwide, affecting approximately 210 million people and leading to 3 million deaths

The prevalence and morbidity data greatly understimate the total burden of COPD because the disease is usually not diagnosed until it is clinically apparent and moderately advanced. Furthermore, population-based estimates of COPD prevalence by region are problematic since the disease is progressive, measurement tools and definitions still vary among studies, and implementation of spirometry is often not feasible in developing regions (Lopez et al., 2006a). A recent systematic review and meta-analysis on global burden of COPD reported a prevalence of physiologically defined COPD of 9-10% in adults (Halbert et al., 2006). These

**3. Chronic obstructive pulmonary disease: Epidemiological data** 

**2. Ageing population: Demographics trends** 

2050 (Gavrilov & Heuveline, 2003).

dramatically.

hospital stay.

of care for COPD.

annually (WHO, 2011).

data agree with results from the BOLD study, a population-based prevalence study including participants from 12 sites worldwide (n=9425), reporting a prevalence of COPD stage II or higher of 10.1% overall, 11.8% for men and 8.5% for women (Buist et al., 2007).

In England the rate of COPD in the population is estimated at between 2% and 4%, representing between 982.000 and 1.96 million people. The diagnosed prevalence of COPD was 1.5% of the population in 2007/08 according to the Quality Outcome Framework (QOF) statistical bulletin. Approximately 835.000 people in England have been diagnosed with COPD in 2008/09. However, it is currently estimated that over 3 million people have the disease and that an estimated 2 million have undiagnosed COPD, among whom it is considered that 5.5% will have COPD at the mild end of the spectrum (NICE guidelines, update 2010).

Recent available data suggest that a pooled prevalence on spirometric basis is about 9% in European adults, with 4-6% of them suffering from a relevant clinical form of the disease. In Italy, prevalence of COPD is 4.5%, on average.

The reported total prevalence of chronic bronchitis in U.S. adults ranged from a high of 55 (2001) cases per 1.000 to a low of 34 (2007). The prevalence of chronic bronchitis appears to have peaked in 2001, followed by a subsequent decline from 2001 to 2007. In 2008, however, there was an increase in the prevalence (44 case per 1.000) compared to the previous year, and this prevalence was the same in 2009 (data from the U.S. National Health Interview Survey-NHIS, 1999-2009).

The epidemiology of COPD in five major Latin American cities (São Paulo, Santiago, Mexico city, Montevideo and Caracas) has been provided by the PLATINO project , launched in 2002: rates of COPD range from 7.8% in Mexico city to 19.7% in Montevideo, suggesting that COPD is a greater health problem in Latin America than previously realized (Menezes et al., 2005). COPD is emerging as public health problem also in the Middle Est and North Africa countries. In 2001, the prevalence of COPD in Africa was estimated 179/100.000 and 301/100.000 in eastern Mediterranean countries (Lopez et al., 2006b).

Currently, in the European Union COPD and asthma, together with pneumonia, are the third most common cause of death, while in North America COPD represents the fourth leading cause of death. Five year survival from diagnosis is 78% in men and 72% in women with clinically mild disease, but falls to 30% in men and 24% in women with severe disease. (NICE guidelines, update 2010). Due to an aging population, increase in COPD prevalence and mortality are expected in the coming decades. The World Health Organization (WHO) has estimated that COPD will be the third leading cause of death for both males and females worldwide by the year 2030, surpassed only by heart disease and stroke (WHO, 2011).

Burden of COPD can also be measured in disability-adjusted life years (DALYs). Worldwide, COPD is expected to move up from the 12th leading cause of DALYs in 1990 to the 5th leading cause in 2020 (Lopez et al., 2006 b).

In the United States COPD accounts for 15.4 million physician visits, 1.5 million emergency department visits and 636.000 hospitalizations each year (Dalal et al., 2011). In Italy, COPD is the fourth highest cause of hospital admission (130.000 admissions every year). In the UK COPD is the second largest cause of emergency admission and the most common cause for emergency admission to hospital due to respiratory disease. One fifth (21%) of bed days

Hospital at Home for Elderly Patients

et al., 2004).

(NICE guidelines, update 2010).

support (Peces-Barba et al., 2008).

with Acute Exacerbation of Chronic Obstructive Pulmonary Disease 379

When an exacerbation of COPD has been diagnosed, to define its severity is essential. Quantification of severity is important in medical management as well as in determing the setting of care (Celli et al., 2004). At present, there is not a validated method for quantifying the severity of exacerbation. Generally, the intensity of the underlying COPD must be considered, as well as comorbidity and a history of previous exacerbations. In addition to these factors, the progression of the symptoms, response to therapy, and availability of adequate home care must be considered in order to decide whether hospitalization is necessary. However, grading of the severity of mild to moderate exacerbations remains contentious since they can be categorised either on clinical presentation (essentially

The most recent position paper of the American Thoracic Society and the European Respiratory Society (ATS/ERS task force) provide a three levels operational classification of severity of COPD exacerbations which allows to identify the best setting of care according to specific elements of clinical evaluation and diagnostic procedures. Level I: patient can be treated at home, Level II: requires hospitalization, Level III: leads to respiratory failure (Celli

In the National Institute for Clinical Excellence (NICE) guidelines (update 2010), hospital-athome and assisted-discharge schemes are recommended as a safe and effective alternative to conventional hospitalization (Grade A), particularly for patients with less severe exacerbations. The same authors admit that, currently, there are insufficient data to make firm recommendations about which patients with an exacerbation are most suitable for hospital-at-home or early discharge, and patient selection should depend on the resources available, absence of factors associated with worse prognosis and patient's preference

The joint guidelines of the Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) and the Latin American Thoracic Society (ALAT) indicate home hospitalization only for patient without signs of severity such as diminished level of consciouness, abnormal chest radiograph, hypercapnia with acidosis, significant comorbidities, need of ventilatory

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines (update 2009) state that "admission of patient with severe COPD exacerbations to intermediate or special respiratory care units may be appropriate if personnel, skills, and equipment exist to

A first feasibility analysis of home-based services to prevent conventional hospitalization of COPD exacerbations was reported in 1999 by Gravil and collegues (Gravil et al., 1998). Subsequent controlled trials confirmed both safety and cost reduction when these types of services were applied to selected COPD patients (Cotton et al., 2000; Davies et al., 2000;

In a review and a meta-analysis including 7 robust RCTs (n=754 patients) Ram and collegues evaluated the overall efficacy of hospital at home schemes, showing that selected patients presenting to hospital emergency departments with acute exacerbation of COPD can be successfully treated at home when supported by visiting respiratory nurses at home. Authors suggested that approximately 25% of the patients with COPD who presented at the

identify and manage acute respiratory failure successfully" (GOLD, 2009).

Hernandez et al., 2003; Ojoo et al., 2002; Skwarska et al., 2000).

symptoms) or healthcare use resources (Rodriguez-Roisin, 2006).

used for respiratory disease treatment are due to COPD, such that COPD accounts for more than one million "bed days" each year in hospitals in the UK (NICE guidelines, update 2010).

The impact of hospitalization for acute exacerbations is significant; mortality during admission is > 10% and mortality during the year after discharge following treatment for acute COPD exacerbation is 25-40% (Escarrabill, 2009).

An acute exacerbation of COPD is not an exceptional or unique event. The Risk Factors of COPD Exacerbation Study (EFRAM) found that 63% of patients were readmitted during the year following an exacerbation (Garcia-Aymerich et al., 2003). Patients with COPD experience exacerbations one to three times a year, with treatment often requiring emergency room care or hospitalization, which contributes substantially to the financial burden of the disease (Dalal et al., 2011).

Various observational studies have found that inpatient care accounts for 50-75% of the direct medical costs of COPD. This cost increases with disease severity: inpatient costs of patients with stage III (severe) disease are double those of patients with stage II (moderate) disease and 6.5 times greater than those of patients with stage I (mild) disease (Dalal et al., 2011).

The indirect cost of COPD are substantial with an impact on annual productivity amounting to an estimated 24 million lost working days per annum. There is little data available to quantify other indirect costs such as carer time and inability to carry out non-occupationally related activity (NICE guidelines, update 2010).

There continues to be high demand for acute care hospital beds for patients with an exacerbation of COPD. Recent reports highlight the fact that although the acute hospital is the standard venue for providing acute medical care, it may be hazardous for older persons, who commonly experience iatrogenic illness, functional decline, and other adverse events. One way to decrease or avoid admissions to hospital is to provide people with acute care treatment at home.
