Spirometry in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease affects about 1% of the total UK population¹ and is a major cause of disability and mortality worldwide. Timely diagnosis and subsequent staging of severity of disease both require spirometry, which in theory can be performed by trained general practitioners (GPs) and their practice staff.²,³ However, numerous barriers impede the implementation of spirometry in primary care.

Several guidelines exist for the management of patients with chronic obstructive pulmonary disease, including those from the UK National Institute for Health and Clinical excellence (NICE)⁴ and the Global Initiative for Chronic Obstructive Lung Disease (GOLD; www.goldcopd.com). All guidelines stress the central role of spirometry in diagnosing and managing the disease in primary care, but this does not guarantee that GPs will use this technique consistently in the care of patients with respiratory symptoms.⁵

Several models to provide spirometry test results exist, depending on local circumstances; these include regional primary care diagnostic services and hospital based lung function laboratories with open access for primary care patients.⁶ However, the most practical and timely solution is for GPs to have their own spirometer in the practice.⁷ In the United Kingdom about 80% of general practices own a spirometer,⁸ but these instruments are still scarce in large parts of the world, even though prices have dropped considerably in the past few years. Trained practice staff who have the skills and time to fit and maintain spirometry of sufficient quality into the daily practice routine⁹ may also be in short supply.¹⁰ In addition to the practical issues, GPs' lack of confidence in their ability to interpret the test results is a crucial barrier—often neglected in the guidelines to effective implementation of spirometry.⁸ Many GPs view spirometry as a complex diagnostic tool, like electrocardiography. This fact was clearly illustrated in a recent UK study that reported low levels of self confidence in interpreting spirometric tests in 160 general practices where GPs and nurses had been trained for half a day—only a third of these professionals trusted their own interpretative skills.⁸ Confidence about how to proceed once the test results are available is a crucial part of building GPs' confidence in their capacity to diagnose and manage the disease.

Ideally once GPs have had initial spirometry training they should receive continuous advice and support. This could be done in various ways—by another GP with a special interest in respiratory diseases in the same practice or in another practice nearby; by means of a computerised clinical decision support system (SpidaXpert software; www.spirxpert.com); or by consultation or feedback from a chest physician. Although intuitively a promising idea, empirical studies on the effects of ongoing expert support on the interpretative capacity and self confidence of GPs are lacking.

So what needs to happen next? For guidelines on chronic obstructive pulmonary disease to be implemented, concrete working agreements between GPs and chest physicians need to be developed. Chest physicians can act as coaches for their local primary care colleagues in two ways—through patient oriented support (specific feedback for specific patients) or through practice oriented support (as teachers in postgraduate training programmes). This will be beneficial for both parties, as referrals will be more structured and based on agreed criteria, GPs who have performed spirometry will have better insight into the patient's lung function, and chest physicians will benefit from having the results at the initial consultation.¹¹ More broadly, coordinated efforts by health policy makers and the medical profession will be needed to provide the right equipment, training for staff who use it, and continuing quality assurance and support for test interpretation. The burden of chronic obstructive pulmonary disease is sufficiently large to warrant such an approach.