Barriers to Diagnosis of Work-Related Asthma
| Principal investigator(s): | Susan Tarlo
(University of Toronto) |
| Co-investigator(s): | Gary Liss
(University of Toronto) |
| Sponsoring Institution: | University of Toronto |
Objective
Work-related asthma includes both occupational asthma (OA), caused by the workplace environment, and work-aggravated asthma (WAA), which is asthma not caused by work but transiently aggravated by workplace exposures. Delays in the recognition and appropriate management of work-related asthma can increase the need for asthma medication, emergency visits and hospital admissions for asthma. Such delays may result from worker-related factors or factors associated with their workplace as well as potential delays from under-recognition by the attending physician. Several studies have shown that a significant period of time exists between symptom onset and the investigation and diagnosis of OA. Continued exposure and, longer duration of symptoms have been associated with a worse prognosis. This study was designed to identify the various individual and work-related factors associated with time to first physician visit after onset of work symptoms.
Method
One hundred patients with suspected work-related asthma were identified from an Occupational Lung Disease Clinic and 100 claimants to the Ontario Workplace Safety and Insurance Board (WSIB). A questionnaire was administered by one of the investigators to the clinic patients at the time of a clinic visit; this was conducted by telephone interview for the WSIB patients. It included questions to record demographic, work-related factors and time to first physician visit. Chart reviews were also undertaken of those patients who gave their consent for review of clinic files or WSIB files as appropriate; data extracted included medical investigations in order to classify the participants into diagnostic categories.
Results
Among the 200 participants, 80 (40%) had sensitizer-induced OA and eighty seven (44%) WAA. The remaining patients with irritant-induced asthma (4) or unrelated asthma, were excluded from further analyses. In the OA group, risk factors for delay in a diagnostic milestone after developing symptoms included male sex (p=0.001), being unmarried (0.05), low education and lack of awareness of the possible association of symptoms with work. Factors associated with other longer diagnostic milestones (time from the onset of symptoms to first physician visit, time to physician recognition of work-relatedness, or time to OA diagnosis) were older age, lack of knowledge of WHMIS programs and lack of knowledge that a workplace agent could cause asthma. For those with WAA the presence of Health and Safety Programs at work significantly reduced the time to diagnostic milestones, as did awareness of OA and of agents at work which could affect asthma. Similar to those with OA, a lower household income and lower education were associated with longer diagnostic milestones.
Conclusions
The associations found in this study suggest the potential for intervention with programs to better educate workers at risk of OA from exposure to workplace sensitizers, and WAA among asthmatics exposed to workplace irritants. It also illustrates the need for better primary care physician education on work-related asthma since only 60% asked about a work-relationship of symptoms. Future research directions could include assessment of programs introduced to improve worker and physician knowledge of work-related asthma to determine whether these will facilitate earlier diagnosis and improved outcome.
Publications
Santos M., Jung H., Peyrovi J., Obadia M., Lou W., Liss G.M., Tarlo S.M. (2005) "Work-related asthma: Factors associated with time to first physician visit." Proceedings of the American Thoracic Society 2:A442.
For more information:
susan.tarlo@utoronto.ca
| | |
