Diagnosing COPD: GP Pharmacy Professional Considerations

As part of our expansion of the guidance on QOF and COPD, we recently published an overview of COPD for primary care professionals and patients. In this post we look at diagnosing COPD, which is something that a lot of pharmacy professionals in general practice are involved with.

The National Institute for Health and Care Excellence (NICE) recommends a consideration of several parameters in the diagnosis and monitoring of COPD. This includes symptoms, spirometry, incidental findings on CT scans or chest X-ray, reversibility testing and thorough history taking. 

Before objective diagnosis, presenting symptoms that should trigger a suspicion of COPD in patients over the over 35 who have a risk factor (generally smoking or a history of smoking) include one or more of exertional breathlessness, chronic cough, regular sputum production, frequent winter ‘bronchitis’ and wheeze. There may also be associated weight loss, reduced exercise tolerance, waking at night with breathlessness, ankle swelling, fatigue and occupational hazards. However, the presence of chest pain and haemoptysis normally indicates the need to consider alternative diagnoses. 

MRC Dyspnoea Scale

In terms of the measure of breathlessness, NICE recommends the use of the Medical Research Council [MRC] Dyspnoea Scale, while the 2024 COPD GOLD framework advocates the modified MRC (mMRC) scale. In practice, as discussed in our post on CODP and QOF, QOF requires the use of the MRC scale, which is reproduced below for information purposes.

The logic behind the mMRC scale is that on the original scale, even healthy individuals would have a grading of 1, which arguably is not of much use from a diagnostic perspective, hence the elimination of this grade to end up with just four grades on the mMRC scale.

Spirometry

The next essential tool in diagnosis is spirometry, which should be performed under four conditions: diagnosis, to reconsider the diagnosis, for people who show an exceptionally good response to treatment; and to monitor disease progression. Essentially, it is not possible to definitively diagnose a patient as having COPD without spirometry. This is because of the risk of misdiagnosis in the event that the patient has other conditions such as interstitial lung disease. 

The British Medical Journal has a useful animated video on that explains spirometry for health professionals, namely what spirometry is and how to interpret the results. This is shown below.

The American lung Association provides a more patient-friendly version on its YouTube channel that also uses the larger tabletop device. This is shown below.

NICE adds some practical tips about the use of spirometry, namely the need to consider alternative diagnosis or investigations for older people who have an FEV1/FVC ratio below 0.7 but do not have typical symptoms of COPD; or considering a prositive diagnosis of COPD in younger people who have symptoms of COPD, even when their FEV1/FVC ratio is above 0.7. 

What about incidental discoveries?

While reviewing documents from secondary care, you may come across individuals who have incidental findings of emphysema or signs of chronic airways disease on chest X-ray or CT scan. Are they sufficient by themselves in diagnosing COPD?

In such cases, a primary care respiratory review, including spirometry testing where the patient is symptomatic, is recommended. Asymptomatic patients should be counselled on the risks of smoking, if relevant, asked if they have a family history of lung disease or considered for alternative diagnoses such as AATD. While no immediate pharmacological intervention is warranted in asymptomatic cases, patients should be aware that the presence of emphysema on a CT scan is an independent risk factor for lung cancer. 

NICE also recommends other diagnostic tests at the time of diagnosis in addition to spirometry. These include a chest radiograph to exclude other pathologies; a full blood count to identify anaemia or polycythaemia and calculation of body mass index (BMI).Where diagnostic uncertainty remains, NICE provides a useful list of additional investigations that may be undertaken here.

In our next post, we look at the main differential diagnoses of COPD. If you haven’t subscribed yet, and don’t want to miss any posts, click here to be directed to our subscription page.

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