Applied Epidemiology

Epidemiology of Chronic Obstructive Pulmonary Disease

(COPD)

By Chris Callan

23 April 2008

What is COPD?

• COPD is a serious lung disease that over time, makes it hard to breathe – long term condition

• COPD is sometimes referred to as emphysema or chronic bronchitis

• Healthy airways and air sacs in the lungs are elastic

• COPD, the airways and air sacs are partially blocked, which makes it hard to get air in and out

Who is at risk? • COPD is common >40yrs with a history of smoking (either current or former smokers)

• Smoking is the most common cause of COPD-it accounts for as many as 9 out of 10 COPD-related deaths

• Long-term exposure to things that can irritate your lungs, like certain chemicals, dust, or fumes in the workplace.

• Heavy or long-term exposure to secondhand smoke or other air pollutants may also contribute to COPD

• COPD is caused by a genetic condition known as alpha-1 antitrypsin, or AAT, deficiency. People with AAT deficiency can get COPD without above exposures

What are the symptoms? • Constant coughing, sometimes called "smoker's cough"

• Shortness of breath while doing activities, even basic tasks if COPD is severe

• Excess sputum production, frequent chest infections

• Feeling like you can't breathe

• Not being able to take a deep breath

• Wheezing

• COPD develops slowly, and can worsen over time

How are you tested for COPD?

• Test for COPD is called Spirometry

• Simple, non-invasive breathing test that measures the amount of air a person can blow out of the lungs (volume) and how fast he or she can blow it out (flow)

• Results will indicate presence of COPD & severity

• The spirometer measures the total amount exhaled, called the forced vital capacity (FVC), and how much you exhaled in the first second, called the forced expiratory volume in 1 second (FEV1)

The guidelines from NICE adopt the following classification:3

50% to 80% predicted FEV1 = mild COPD

30% to 50% predicted FEV1 = moderate COPD

Less than 30% predicted FEV1 = severe COPD

Preventative care?

• Quit smoking

• Avoid exposure to pollutants

• Visit your doctor regularly

• Take pre-cautions against flu

Treatment options?

• Medications (such as inhalers, these relax the muscles around the airways)

• Pulmonary Rehabilitation (learn how to maintain day to day tasks)

• Physical Activity Training (aimed to make you stronger and the strengthen breathing muscles)

• Lifestyle Changes (quit smoking)

• Oxygen Treatment (usually with severe COPD)

• Surgery (usually with very severe COPD, lung surgery to improve breathing)

Epidemiology of COPD – National • Prevalence is approx. 1.4% in the UK

• Adults > 40yrs smoke/ex-smokers

• Suggestion that problem is under diagnosed

10% for >75yrs

PCT COPD PrevalanceGateshead PCT 2.3%

South Tyneside PCT 2.8%

Sunderland Teaching PCT 2.9%

Source: NCHOD 2005-06

• The disease is progressive and patients deteriorate but the natural history of the disease varies in different people

• In patients who stop being exposed to cigarette smoke and other noxious substances the disease may continue to progress, but the rate of decline may slow

• Repeated over exertion may lead to irreversible decline in lung function

Epidemiology of COPD - National

Significant variation across

the country!

Source: Yorkshire and Humberside PHO

Epidemiology of COPD - International

• The World Health Organization (WHO) estimates that COPD as a single cause of death shares 4th and 5th places with HIV/AIDS (after coronary heart disease, cerebrovascular disease and acute respiratory infection).

• The WHO estimates that in 2000, 2.74 million people died of COPD worldwide.

• According to the WHO, passive smoking carries serious risks, especially for children and those chronically exposed. The WHO estimates that passive smoking is associated with a 10 to 43 percent increase in risk of COPD in adults.

Epidemiology of COPD – NSF announced June 06

Routine Data Sources for COPD

Primary Care – QoF Data (2006/07)

Organisation % PrevalenceNational 1.4North East SHA 2.3County Durham PCT 2.3Darlington PCT 1.8Gateshead PCT 2.2Hartlepool PCT 2.2Middlesbrough PCT 2.4Newcastle PCT 1.9North Tees PCT 1.9North Tyneside PCT 2.0Northumberland CT 2.2Redcar and Cleveland PCT 2.4South Tyneside PCT 2.9Sunderland Teaching PCT 2.8

South Tyneside PCT split by GP Practice

Annual COPD QoF data can be

used for

• Prevalence

• % confirmed COPD with spirometer

• % of patients with recorded FEV1

• % of patients on medication / received flu vaccine

Routine Data Sources for COPD

Accident and Emergency Attendances – SuS

• Monthly data, not COPD specific but can identify attendances associated with respiratory problems

Secondary Care Elective and Non Elective Admissions – SuS (2006/07)

• Monthly admission data using HRGs

HRG Code HRG Description Elective Non-ElectiveD39 Chronic Obstructive Pulmonary Disease or Bronchitis w cc £1,546 £2,360

D40 Chronic Obstructive Pulmonary Disease or Bronchitis w/o cc £609 £1,752

Outpatient Attendances – SuS (2006/07)

• Monthly attendances data by specialty, not COPD specific but can identify attendances associated with respiratory problems

PCT% of all NEL

admissions 2006-07Cost (£) 2006-07

Gateshead PCT 1.9% £1,057,448South Tyneside PCT 1.7% £661,550Sunderland PCT 1.2% £1,027,598

COPD Non-Elective Admissions

Routine Data Sources for COPD

NHS Direct – Quarterly Report by PCT

• Quarterly data, not COPD specific but can identify number of calls associated with respiratory problems

NCHOD – Annual data

• Prevalence and mortality data

Mortality from bronchitis, emphysema and other COPD (ICD9 490-492, 496 adjusted; ICD10 J40-J44):

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England and Wales

NE SHA

South of Tyne PCTs

PCT COPD PrevalanceGateshead PCT 2.3%

South Tyneside PCT 2.8%

Sunderland Teaching PCT 2.9%

Data Sources for COPD