COPD is being misdiagnosed and missed in general practice while smoking cessation, one of the best ways GPs can help their patients, is also under-done according to new research.

Baseline data from the Review of Airway Dysfunction and Interdisciplinary Community-based care in Adult Long-term Smokers (RADICALS) study in Melbourne found 37% of participants with a prior COPD diagnosis did not meet the spirometric definition of COPD.

A further 17.6% of patients without a prior COPD diagnosis had spirometry results consistent with COPD.

Of the current smokers, more than half (52%) had tried to quit in the previous year with most reporting difficulties including side effects from smoking cessation medications. Nicotine replacement therapies and varenicline were the most commonly used pharmacotherapies.

Smokers were also frequently trying non-evidence based methods for quitting such as hypnotherapy and e-cigarettes.

The study comprised more than 1,000 patients – current or former smokers aged over 40 – across 41 general practices.

Less than half (43%) of practices had a spirometer and only a minority had staff trained in spirometry (35%), COPD management (20%) or smoking cessation (17%).

Co-author Professor Michael Abramson, deputy head of the Department of Epidemiology and Preventive Medicine at Monash University, said the results were – disappointingly – consistent with previous research.

He said feedback from the earlier Spiro-GP study suggested GPs found investment in spirometry, regular calibration and staff training was not worth it for the MBS reimbursement.

“The same reason probably applies now. It’s incredibly effort dependent to get good reliable measurement of lung function – it’s a fine art.

“A lot of GPs are not all that confident in interpreting spirometry even though it’s in the guidelines and a lot of resources have been developed.”

Professor Abramson added that smoking cessation required more GP support including a focus on evidence-based therapies and ongoing counselling.

“It’s not the sort of thing that can be sorted out in one consultation.”

However a lot of GPs don’t necessarily approach it with a great deal of enthusiasm, he said.

“Smoking cessation is the main thing we can offer our COPD patients. It’s more powerful than all the medications we have available for treating the disease.”

The ongoing study will involve interventions including smoking support, home pulmonary rehabilitation and home medicines reviews.