To the Editor: The informative study by Simons and colleagues1 has highlighted a major concern. Chronic obstructive pulmonary disease (COPD) is one of Australia’s top four causes of death and burden of illness,2 yet the authors have made no mention of COPD. Failure to recognise the importance of this disease is an endemic attitude in Australia and globally3-5 that results in under-representation of COPD in epidemiological surveys and in inadequate funding for effective treatments and research.

The study found that peak expiratory flow (PEF) provides the highest hazard ratios for predicting time to death in women (and the second highest in men). There is even a “dose–response” effect. Using the term “impaired PEF” is a bit like saying “impaired ECG” without attributing a diagnosis. PEF is a measure of airway calibre, and impairment of PEF indicates airway disease — largely COPD in this population. Smoking accounts for about 85% of the risk of COPD, and about 50% of smokers develop airflow limitation,4-6 so it is not surprising that the interaction between PEF and smoking was the most important predictor of reduced survival in this large cohort.

It’s time to stop hiding our heads in the ashtray! Smoking combined with low PEF is COPD. We must demand that our medical and epidemiological professions uncover people with undiagnosed COPD. Early diagnosis is simple.5 It’s not normal to be unable to keep up with friends at work or during recreation because of breathlessness, and a daily cough is really an airway disease. If symptoms are acknowledged, spirometry will confirm the diagnosis. We should help our patients to enunciate these hidden symptoms so their condition can be diagnosed accurately, and effective management begun, as highlighted in the “COPDX management guidelines”.5 Primary and secondary prevention must focus on reducing smoking among young people. Smoking cessation, the use of effective drugs, and pulmonary rehabilitation are the cornerstones of COPD therapy that lead to better quality survival.

COPD is common and under-diagnosed. Simons et al have partly exposed this deadly condition. Their data, added to other Australian data,7 should trigger actions that facilitate earlier diagnosis throughout Australia and support delivery of effective treatment to the thousands “dying a slow death” from COPD.

Australia’s illness burden from COPD is high. Its prevalence and burden in Australia are rising, especially in women. Globally, the World Health Organization expects COPD to rise from 12th to 5th as a cause of illness burden by 2020.

We must acknowledge that PEF impairment is not simply a mysterious risk factor for early “all-cause mortality”, but is indicative of COPD being a major contributor to death in this population.

In reply: The prospective Dubbo Study of the elderly has produced a series of publications in which reduced peak expiratory flow (PEF) has been shown to be associated with increased risk of death,1,2 as well as increased risk of heart attack,3 ischaemic stroke4 and admission to a nursing home. 5 We have employed a purely statistical definition of impaired PEF, namely the lowest third of our sex-specific population distribution. We agree that many subjects so defined with impaired PEF, and who are smokers, will have underlying and potentially undiagnosed chronic obstructive pulmonary disease (COPD).

Epidemiological studies have highlighted the importance of impaired PEF. It is now time for health professionals to implement the COPDX management guidelines referred to by Frith6 in a still more effective manner and to devise better prevention programs.