One in 10 people identified as having Chronic Obstructive Pulmonary Disease (COPD) have no definitive diagnosis, yet the majority of them are being prescribed inhaled drugs for a condition they are unlikely to have - according to new research presented at the British Thoracic Society’s Winter Meeting.

The study of 16,479 COPD patients across Hampshire has shown that 10% had no evidence of airflow obstruction to support their diagnosis, and yet 79% were receiving inhaler treatments.

Chronic Obstructive Pulmonary Disease (COPD) is the name for a group of lung diseases that narrow the airways causing breathing difficulties. COPD inflicts a huge toll on patients, their carers, and on the NHS. In total, 1.2 million people in the UK have been diagnosed with COPD.  There are 30,000 deaths from the disease in the UK each year.

 The study was prompted by the National COPD Audit Programme in 2016 which had revealed that in a quarter of cases nationwide, spirometry (a key breathing test) values were not consistent with the given diagnosis of Chronic Obstructive Pulmonary Disease (COPD).

Dr Lynn Josephs, Clinical Research Consultant Fellow at The University of Southampton scrutinised anonymised data, to review the characteristics, medication and other health conditions of patients diagnosed with COPD - comparing those with, and without, evidence of airflow obstruction.

The next stage of data analysis was to question whether there was an asthma diagnosis which might explain the study findings, since similar inhalers are prescribed for both conditions.  

Yet, even after excluding all patients with a diagnosis of asthma, which left 12,235 patients with COPD, 1,182 still had no evidence of airflow obstruction from a spirometry test, and yet 50% of these were receiving long-acting bronchodilator inhalers and 50% were receiving inhaled corticosteroids; both of which are expensive treatments only recommended for confirmed, moderate or severe COPD.  

Only 28% of patients were on no respiratory treatment.

Dr Josephs, who led the research, says: “It is well known that there is under-diagnosis of COPD and this is a major problem, yet this study highlights an additional issue that there are also a considerable number of cases of over-diagnosis. Without confirmatory spirometry testing, which is fundamental to diagnosis, a high number of patients were still diagnosed with, and given medication for, COPD.  

"Since there is no evidence of COPD, nor of asthma in some cases, there is concern that the prescriptions given may not always be appropriate – either being ineffective or potentially harmful to those patients.

"We would advocate a reassessment of such patients, as there may be other causes for their symptoms which have been missed, and alternative treatment options.

"Both under-diagnosis and over-diagnosis of COPD highlight the need for adequate access to quality assured spirometry in primary care.”