Background: Ultraviolet radiation (UVR) from the sun has both harms and benefits to health. We developed an agent-based microsimulation model to estimate UVR-related disease burden for Australia and New Zealand.
Methods: Five diseases were modelled that are associated with over-UVR exposure (i.e., melanoma, keratinocyte skin cancer (KC), cataract), or under-UVR exposure (i.e., multiple sclerosis and fragility fractures). We used large datasets of environmental UVR, sun behaviours and socio-demographic variables. We combined published incidence for each disease with the population attributable risk formula to quantify the expected disease outcomes and government healthcare costs attributable to sun exposure. We assessed the relative burdens for each disease within Australia and New Zealand over 20 years.
Results: In Australia, we estimated sun-exposure contributes to five common diseases that when combined is attributed to 22.7 million incident cases, $262.2 billion in healthcare costs and $61.7 billion in patient out-of-pocket costs. Cataracts are predicted to account for 44% of all cases, followed by fragility fractures (30%) and KCs (20%). Fragility fractures, through vitamin D deficiency, account for 89% of total government healthcare costs for the five diseases followed by cataracts (5%) and melanoma (2%). Melanoma in situ accounts for 68% of the total melanoma cases, contributing to KC and melanoma having similar healthcare costs. New Zealand results are broadly similar to those in Australia.
Conclusions: Fragility fractures have the highest health and cost burdens in Australia and New Zealand among UVR-related diseases. Sun behaviours are critical for understanding and reducing UVR-related disease burdens and costs.