title: A systematic review of the diagnosis of occupational asthma.
abstract: BACKGROUND
  This study systematically reviews literature regarding the diagnosis of occupational asthma (OA) and compares specific inhalation challenge (SIC) testing with alternative tests.
  
  
  METHODS
  Electronic databases and trials registries were searched; additional references were identified from bibliographic searches of included studies, hand searches of conferences, and author contacts. Various study designs (clinical trials, cohorts, cross-sectional, or case series) were included involving workers with suspected OA. All diagnostic tests were compared to a "reference standard," and two researchers independently extracted 2 x 2 data. Pooled sensitivities and specificities (95% confidence intervals [CIs]) were derived.
  
  
  RESULTS
  Seventy-seven studies were included. For high molecular weight (HMW) agents, the nonspecific bronchial provocation (NSBP) test, skin-prick test (SPT), and serum-specific IgE had sensitivities > 73% when compared to SIC. Specificity was highest for specific IgE vs SIC (79.0%; 95% CI, 50.5 to 93.3%). The highest sensitivity among low molecular weight asthmagens occurred between combined NSBP and SPT vs SIC (100%; 95% CI, 74.1 to 100%). When compared to SIC, specific IgE and SPT had similar specificities (88.9%; 95% CI, 84.7 to 92.1%; and 86.2%; 95% CI, 77.4 to 91.9%, respectively). For HMW agents, high specificity was demonstrated for positive NSBP tests and SPTs alone (82.5%; 95% CI, 54.0 to 95.0%) or when combined with specific IgE (74.3%; 95% CI, 45.0 to 91.0%) vs SIC. Sensitivity was somewhat lower (60.6% and 65.2%, respectively).
  
  
  CONCLUSIONS
  In appropriate clinical situations when SIC is not available, the combination of a NSBP test with a specific SPT or specific IgE may be an appropriate alternative to SIC in diagnosing OA. While positive results of single NSBP test, specific SPT, or serum-specific IgE testing would increase the likelihood of OA, a negative result could not exclude OA.
authors.affiliation: Department of Public Health Sciences, University of Alberta, Edmonton Canada.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Beach
authors.forename: Kelly
authors.initials: K
authors.lastname: Russell
authors.forename: Sandra
authors.initials: S
authors.lastname: Blitz
authors.forename: Nicola
authors.initials: N
authors.lastname: Hooton
authors.forename: Carol
authors.initials: C
authors.lastname: Spooner
authors.forename: Catherine
authors.initials: C
authors.lastname: Lemiere
authors.forename: Susan M
authors.initials: SM
authors.lastname: Tarlo
authors.forename: Brian H
authors.initials: BH
authors.lastname: Rowe
mesh_terms: D001249:Asthma / Q000175:diagnosis*; D006801:Humans; D007159:Immunologic Tests; D009784:Occupational Diseases / Q000175:diagnosis*; D012129:Respiratory Function Tests