O33-3 Chilean workers exposed to silica dust: a cost effective analysis of increase the coverage in surveillance silicosis program

Introduction Silicosis is one of the major occupational health diseases in Chile. 5.4% (347.662) of chilean workers have been estimated to be exposed to silica dust, nevertheless recent national reports suggest that the surveillance silicosis program coverage is suboptimal. The surveillance program includes both medical and environmental interventions. The aim of this research is to determine if an increase in the coverage of the silicosis surveillance program is cost effective and at what level of coverage is cost-effective. Methods A cost effectiveness model was constructed using Tree Age Pro Healthcare 2011 program. Silica exposure was updated from previous studies. Actual levels of surveillance coverage were estimated on 20–35%. Disease Model (DisMod) software was used to estimate the prevalence (0.9) and incidence (0.06) of silicosis in Chile. Mortality rates were estimated based on national rates. Then, Disability Adjusted Lost Years (DALY) for workers exposed to silica dust was estimated. Effectiveness parameters were gathered from international studies. DALYs avoided were estimated using TreeAge Pro. Costs of medical and environmental interventions were estimated with data from workers insurance and assuming 3 stage of silicosis disease. Finally, a cost-effectiveness ratio was calculated for different levels of surveillance coverage. Main results Higher cost-effectiveness ratios were obtained at higher coverage level. Increase in coverage from 35% to 95% of surveillance silicosis program, reduced DALY in 30.7% (2,377 of a total number of the actual 5,456 AVISA), and avoided 62.2% of death due to silicosis. To obtain these results, high levels of employer’s compliance and worker’s adherence to preventive measures was assumed (85%). Important lowering costs are estimated due to early diagnosis. Conclusion Extending the surveillance coverage of silicosis program is increasingly cost effective and represents an opportunity to diminish this preventable disease.