Table 7. Effect of age at diagnosis on outcome of occupational asthma

First author [ref.]	Main conclusion	SIGN grade	Study type	Exposure/occupation	Subjects n
Descatha [28]	No relationship	2+	Case series	Various HMW and LMW agents	227
Rachiotis [6]	+	1-	Systematic review	Various	2376
Chang-Yeung [17]^#	+	2-	Longitudinal	Western red cedar	125
Park [21]^#	No relationship	2-	Longitudinal	TDI	41
Mapp [22]^#	No relationship	2-	Longitudinal	TDI	35
Moscato [25]^#	+	2+	Longitudinal	Various	29

SIGN: Scottish Intercollegiate Guidelines Network; HMW: high molecular weight; LMW: low molecular weight; TDI: toluene diisocyanate. +: effect of age on asthma outcome. ^#: these articles are included in the review by Rachiotis et al. [6].