Estimating the costs of job related arthritis.

OBJECTIVE: To present the first estimate of the costs of job related osteoarthritis (OA) in the USA. METHODS: Data were drawn from national data sets collected by the US Bureau of Labor Statistics, the US National Center for Health Statistics, and existing cost estimates for arthritis in the literature. We used proportional attributable risk (PAR) models to estimate the percentage of acute and repetitive injuries resulting in OA. These PAR vary between men and women. We used the human capital method that decomposes costs into direct categories such as medical expense and indirect categories such as lost earnings. RESULTS: We estimate job related OA costs US$3.41 to 13.23 billion per year (1994 dollars). Our point estimate is that job related OA contributes about 9% ($8.3 billion) to the total costs for all OA. About 51% of job related costs result from medical costs and 49% from lost productivity at work and at home. These costs are likely to underestimate the true burden since costs of pain and suffering as well as costs to family members and others who provide home care are ignored. CONCLUSION: The cost of job related arthritis is significant and has implications for both clinical and public policy. Depending on the PAR selected, job related arthritis is at least as costly as job related renal and neurological disease combined, and is on a par with the costs of job related chronic obstructive pulmonary disease and all asthma, whether job related or not.

Elevated symptom prevalence associated with ventilation type in office buildings.

The California Healthy Building Study was designed to assess relations between ventilation system type and office worker symptoms in a set of U.S. buildings selected without regard to worker complaints. Twelve public office buildings in northern California meeting specific eligibility criteria were studied in the summer of 1990: three naturally ventilated, three mechanically ventilated (without air conditioning), and six air-conditioned buildings. Questionnaire data were collected from 880 workers in selected spaces within the study buildings. We adjusted effect estimates for various ventilation types for personal, job, and work place factors using logistic regression, and alternatively, using a mixed effects model (SAS/GLIMMIX) to adjust for correlated responses within study spaces. Higher adjusted prevalences of most symptom outcomes were associated with both mechanical and air-conditioned ventilation, relative to natural. With a conservative adjustment for problem building status, the highest adjusted prevalence odds ratios from logistic regression models were for dry or itchy skin [mechanical: odds ratio (OR) = 6.0, 95% confidence interval (CI) = 1.6-22; air-conditioned: OR = 6.0, 95% CI = 1.7-21] and lower respiratory symptoms (mechanical: OR = 2.9, 95% CI = 0.7-11; air-conditioned: OR = 4.0, 95% CI = 1.1-15). GLIMMIX estimates were similar, with slightly wider confidence intervals. Reporting bias was small. These findings of symptom increases within mechanically ventilated and air-conditioned U.S. buildings support previous findings available only from European buildings.