Assessment of impairment/disability due to occupational asthma through a multidimensional approach

Subjects with occupational asthma (OA) are often left with permanent sequelae after removal from exposure, and assessing their impairment/disability should utilise various tools. The aim of the present study was to examine whether: 1) assessment of inflammation in induced sputum is relevant to impairment; and 2) use of questionnaires on quality of life and psychological factors can be useful for the evaluation of disability. In total, 40 subjects were prospectively assessed for permanent impairment/disability due to OA 2 yrs after cessation of exposure. Impairment was assessed as follows: 1) need for asthma medication; 2) asthma severity; 3) airway calibre and responsiveness; and 4) degree of inflammation in induced sputum. Disability was assessed according to quality of life and psychological distress. There was a significant improvement in airway responsiveness and inflammation from diagnosis to the present assessment. Sputum eosinophils > or =2% and neutrophils >60% were present in eight (20%) and 12 (30%) out of all subjects, respectively, one or the other feature being the only abnormalities in 15% of subjects. Quality of life was moderately affected and there was a prevalence of depression and anxiety close to 50%. In the assessment of subjects with occupational asthma, information on airway inflammation and psychological impacts are relevant to the assessment of impairment/disability, although these findings need further investigation.