Asthma under/misdiagnosis in primary care setting: an observational community-based study in Italy

Our study highlights that according to the ECRHS results, asthma should be highly
suspected in 33.2 % in patients diagnosed with a respiratory disease different from
asthma by their GP and undergoing ICS treatment. Furthermore only 16.5 % of the overall
study population had undergone lung function assessment in the last 12 months, despite
suffering from a physician-diagnosed respiratory disease.

The results of our study show a poor accordance between physician-reported and ECRHS
questionnaire-related asthma diagnosis. Assuming the good sensibility and specificity
of the ECRHS questionnaire, the results confirm that Italian GPs do not optimally
recognise respiratory symptoms as asthma manifestations. This finding is in agreement
with previous studies, showing that 7.4 % of enrolled subjects had been newly diagnosed
with asthma during the study and about one quarter of the asthmatic subjects received
no treatment at all 1].

It is not surprising that in our cohort of patients, selected on the basis of ICS
use, many of them had a diagnosis different from asthma. In Italy, patients with COPD,
acute and chronic bronchitis, acute upper respiratory tract infections, rhinitis or
not well defined respiratory symptoms are extensively treated with ICS, as also reported
in other studies, including a large-scale paediatric survey 8].

Among the patients identified as asthmatics according to ECRHS questionnaire, 35 %
had a diagnosis of COPD in GP database, although around 56 % of them had never smoked.
Distinguishing asthma from COPD is often problematic, particularly in smokers and
older adults, and in a significant proportion of patients COPD and asthma features
may coexist 9]: spirometry, besides clinical history, could help to address the question of differential
diagnosis, and it should always be performed in patients with respiratory symptoms.
Nevertheless in our study less than 30 % of asthmatic patients according to the ECRHS
questionnaire and 38.6 % of physician-diagnosed asthmatic patients underwent lung
function assessment during the previous 12 months. Limited prescription of lung function
tests in general practice (physicians may not be fully familiar with the interpretation
of results) and poor accessibility to spirometers, which are mostly available in the
hospital setting due to lack of time to perform office spirometry (in most cases GPs
in Italy do not have technical or nursing support), may account for under-utilization
of spirometry in primary care 10], 11].

Around 20 % of the patients identified as asthmatics according to ECRHS questionnaire
had a diagnosis of upper airway disease in the GP database (allergic or vasomotor
rhinitis or otitis/sinusitis). It is well known that allergic rhinitis and sinusitis
are often associated with asthma and constitute the main risk factor for its development.
Another Italian study showed that subjects with allergic rhinitis show an eightfold
risk of having asthma compared to subjects without allergic rhinitis 12]. Furthermore, in a large cohort study on subjects with allergic rhinitis without
diagnosis of asthma, bronchial hyper-responsiveness and also bronchial obstruction
were detected in a high percentage of patients, both during and outside the pollen
season 13], underlining the importance of lung function assessment in patients with chronic
upper airways symptoms. Nevertheless the lack of asthma identification in these patients
suggests that asthma is still regarded mainly as an intermittent disease, or misrecognized
as a clinical manifestation of viral infections.

Our study has some potential limitation. Firstly, only patients on ICS treatment were
included in the survey, whereas those treated with other respiratory drugs were excluded.
Although inhaled corticosteroids are the gold standard of asthma therapy, in general
practice there is a wide range of treatments for patients with respiratory symptoms.
Thus, the rate of mis/underdiagnosis of asthma observed in this study presumably affects
milder patients. As regards patients treated with various anti-asthmatic agents, such
as combinations of ICS and bronchodilators, recent evidence suggests a considerable
amount of overdiagnosis of asthma 14]. Secondly, untreated patients were excluded from the study population, thus patients
with milder disease have been potentially lost.

Our data suggest that there is still a considerable under/misdiagnosis of asthma in
the Italian primary care settings, and that the use of a validated questionnaire could
be of helpful in identifying patients to address to lung function assessment.