Am. J. Respir. Crit. Care Med., Volume 162, Number 1, July 2000, 112-118

Hospitalization among Workers Compensated for Occupational Asthma

GARY M. LISS, SUSAN M. TARLO, YOKA MACFARLANE, and KA SING YEUNG

Department of Public Health Sciences, and Gage Occupational and Environmental Health Unit, Department of Medicine, University of Toronto, Toronto, Canada; and Ontario Ministry of Labour, Ontario Ministry of Health, and Workplace Safety and Insurance Board, Toronto, Canada

Occupational asthma (OA) can cause persistent symptoms, but populations with OA have not been followed for the development of serious outcomes such as hospitalization. Subjects receiving compensation for OA during 1980-1993, and a comparison sample of workers with musculoskeletal injuries (INJ) were identified from the Ontario Workers' Compensation Board. We also identified for comparison a group of asthmatic patients (AP) seen at a tertiary care hospital clinic during the same period. The file was matched with the Ontario Ministry of Health data base of hospitalizations through 1996. We compared the frequency of hospitalization of the subgroups with that expected in the general population using standardized morbidity ratios (SMRs), and directly by proportional hazards regression. The study group included 844 OA claimants, 1,556 INJ claimants, and 402 AP. Although admissions for all causes combined and respiratory disease among INJ were less than expected in the general population, admissions for all causes combined exceeded that expected among OA and AP. Admissions for respiratory disease were markedly greater than expected among OA (SMR 9.2) and AP (SMR 17) because of even greater excess admissions for asthma (SMRs 45 and 81, respectively). Compared with those with INJ, those with OA were more likely to be hospitalized for all causes combined (adjusted relative risk [RR] 1.4, 95% confidence interval [CI] 1.2 to 16); cardiovascular disease (RR 1.4, 95% CI 0.9 to 2.0); respiratory disease (RR 5.4, 95% CI 3.8 to 7.7); and asthma (RR 28.1, 95% CI 10.2 to 77.2) but not for malignancies (RR 1.0) or injuries (RR 0.9). Those with OA were admitted to hospital about half as frequently as AP for respiratory disease and asthma (although this was modified by smoking status and sex), but were 30% more likely to be admitted for ischemic heart disease (IHD). Among the OA claimants, factors that were significantly associated with hospitalization for asthma included older age and exposure to agents other than isocyanates. Those with OA became less likely to be hospitalized for asthma with increasing time after onset, particularly after 5 or more years. We conclude that subjects with OA suffer higher rates of hospitalizations for all causes combined, respiratory disease, and asthma than other workers, although less than among AP seen at a tertiary care center.

This article has been cited by other articles:

				M. S. Santos, H. Jung, J. Peyrovi, W. Lou, G. M. Liss, and S. M. Tarlo Occupational Asthma and Work-Exacerbated Asthma: Factors Associated With Time to Diagnostic Steps Chest, June 1, 2007; 131(6): 1768 - 1775. [Abstract] [Full Text] [PDF]

				C V Breton, Z Zhang, P R Hunt, E Pechter, and L Davis Characteristics of work related asthma: results from a population based survey Occup. Environ. Med., June 1, 2006; 63(6): 411 - 415. [Abstract] [Full Text] [PDF]

				H Alamgir, M Koehoorn, A Ostry, E Tompa, and P Demers An evaluation of hospital discharge records as a tool for serious work related injury surveillance. Occup. Environ. Med., April 1, 2006; 63(4): 290 - 296. [Abstract] [Full Text] [PDF]

				S. M. Tarlo and G. M. Liss Prevention of occupational asthma--practical implications for occupational physicians Occup. Med., December 1, 2005; 55(8): 588 - 594. [Abstract] [Full Text] [PDF]

				S M Tarlo and G M Liss Evidence based guidelines for the prevention, identification, and management of occupational asthma Occup. Environ. Med., May 1, 2005; 62(5): 288 - 289. [Full Text] [PDF]

				P D Blanc, M D Eisner, L Trupin, E H Yelin, P P Katz, and J R Balmes The association between occupational factors and adverse health outcomes in chronic obstructive pulmonary disease Occup. Environ. Med., August 1, 2004; 61(8): 661 - 667. [Abstract] [Full Text] [PDF]

				C. Iribarren, I. V Tolstykh, and M. D Eisner Are patients with asthma at increased risk of coronary heart disease? Int. J. Epidemiol., August 1, 2004; 33(4): 743 - 748. [Abstract] [Full Text] [PDF]

				O. Vandenplas, K. Toren, and P.D. Blanc Health and socioeconomic impact of work-related asthma Eur. Respir. J., October 1, 2003; 22(4): 689 - 697. [Abstract] [Full Text] [PDF]

				Proceedings of the First Jack Pepys Occupational Asthma Symposium Am. J. Respir. Crit. Care Med., February 1, 2003; 167(3): 450 - 471. [Full Text] [PDF]

				G M Liss and S M Tarlo Work related asthma Occup. Environ. Med., August 1, 2002; 59(8): 503 - 504. [Full Text] [PDF]

				S M Tarlo, G M Liss, and K S Yeung Changes in rates and severity of compensation claims for asthma due to diisocyanates: a possible effect of medical surveillance measures Occup. Environ. Med., January 1, 2002; 59(1): 58 - 62. [Abstract] [Full Text] [PDF]

				M. J. TOBIN Asthma, Airway Biology, and Allergic Rhinitis in AJRCCM 2000 Am. J. Respir. Crit. Care Med., November 1, 2001; 164(9): 1559 - 1580. [Full Text] [PDF]

				S. M. Tarlo, K. Leung, I. Broder, F. Silverman, and D. L. Holness Asthmatic Subjects Symptomatically Worse at Work : Prevalence and Characterization Among a General Asthma Clinic Population Chest, November 1, 2000; 118(5): 1309 - 1314. [Abstract] [Full Text] [PDF]