Practices should check their COPD registers, say researchers, after an audit found patients may be misdiagnosed.
Checks of Welsh GP records carried out by the Royal College of Physicians found most patients did not have a gold-standard spirometry test record, and of those that did a quarter had a result that suggested they did not actually have COPD.
The audit, conducted in 2014/15 in 61% of practices in Wales, found that only 19% of COPD patients had a post-bronchodilator FEV1/FVC recorded, the researchers reported in the British Journal of General Practice.
Among these patients, 25% had incompatible spirometry (FEV1/FVC ≥0.70), suggesting they may have been misdiagnosed.
The researchers calculated that at the time of the audit, as many as 16,000 patients may have been misdiagnosed in Wales.
They also estimated that the total cost of inhalers prescribed for audit patients with incompatible spirometry and no known asthma was approximately £1m per year.
Potential reasons may include issues around correct use of read codes, patients being diagnosed in secondary care, and difficulty accessing tests, the researchers said.
The results have already led to several funded initiatives to improve COPD care in Wales, including an optional practice audit as part of QOF, training offered to more than 1,000 nurses and a quality tool due to be launched later this year to help identify patients who may need review.
But the researchers said similar audits done in individual CCGs in England suggest the problem is not confined to Wales and encouraged practices to check their records.
English practices did not take part in the RCP audit and there is no national programme, although some CCGs have opted to fund work on COPD, the BMA said.
Study leader Dr Marie Fisk from the University of Cambridge said the reasons for the results they found were complex and included the fact that in some patients spirometry is not the right test to do and that interpretation of tests was difficult.
The researchers concluded that ‘a concerted effort to determine an accurate diagnosis in these patients is urgently needed’ to reduce potential harm and medical costs and there was no reason to think the situation in England would be different.
‘Some of the clinical team have run similar audits in their English CCGs and found similar results, so yes we would recommend every English practice runs searches of its QOF register to find who has not had post-bronchodilator spirometry and who has had it but has a result with FEV1/FVC ratio =>0.7.’