Assessment of work-related asthma prevalence, control and severity: protocol of a field study

Pulmonary Function Testing in Work-Related Asthma: An Overview from Spirometry to Specific Inhalation Challenge

Work-related asthma (WRA) is a very frequent condition in the occupational setting, and refers either to asthma induced (occupational asthma, OA) or worsened (work-exacerbated asthma, WEA) by exposure to allergens (or other sensitizing agents) or to irritant agents at work. Diagnosis of WRA is frequently missed and should take into account clinical features and objective evaluation of lung function. The aim of this overview on pulmonary function testing in the field of WRA is to summarize the different available tests that should be considered in order to accurately diagnose WRA. When WRA is suspected, initial assessment should be carried out with spirometry and bronchodilator responsiveness testing coupled with first-step bronchial provocation testing to assess non-specific bronchial hyper-responsiveness (NSBHR). Further investigations should then refer to specialists with specific functional respiratory tests aiming to consolidate WRA diagnosis and helping to differentiate OA from WEA. Serial peak expiratory flow (PEF) with calculation of the occupation asthma system (OASYS) score as well as serial NSBHR challenge during the working period compared to the off work period are highly informative in the management of WRA. Finally, specific inhalation challenge (SIC) is considered as the reference standard and represents the best way to confirm the specific cause of WRA. Overall, clinicians should be aware that all pulmonary function tests should be standardized in accordance with current guidelines.

[A questionnaire assessing knowledge level concerning occupational asthma]

INTRODUCTION

Screening for occupational asthma is should still be promoted. In order to improve the efficiency of any educational intervention we need to evaluate the patient's knowledge of the disease.

OBJECTIVES

The aims were to evaluate objectively the knowledge level of Tunisian asthmatic patients concerning occupational asthma using a self-questionnaire in Arabic Tunisian dialect, then to conduct a validation process of the questionnaire.

METHODS

We followed De Vellis's rules during all stages of redaction of the self-questionnaire. It contained 18 items allocated in 4 dimensions: knowledge about asthma; knowledge about occupational asthma; prognosis of occupational asthma; prevention of occupational asthma. A pre-test was conducted on 18 asthmatic patients to assess the clarity and comprehensibility of all the questions. The questionnaire was then applied to 107 asthmatic patients.

RESULTS

The statistical analysis proved the discrimination value in 14 of the 18 items. The internal consistency of the questionnaire was demonstrated by a KR20 index of 0.731. Factorial analysis of the principal components showed the reliability of the questionnaire and of its uni-dimensional structure. The statistical findings proved the positive correlation between the mean scores of all its dimensions.

CONCLUSIONS

Using this questionnaire in daily practice should inform health care providers about the level of knowledge of occupational asthma in the targeted population and improve the effectiveness of any further educational intervention.