Slip! Slap! Slop! Cutaneous malignant melanoma incidence and social status in New Zealand, 1995-2000.

Numerous studies have noted a strong social gradient in many types of ill health. In particular, people in more deprived areas tend to be less healthy than those in more affluent communities, even once the demographic and socio-economic differences of the people in those areas have been taken into account. The social gradient is evident for many types of health outcomes, including diseases such as cancer. However, this positive relationship is not evident for rates of melanoma incidence and mortality, with rates of the disease tending to decrease with measures of disadvantage. In this study, we assess the relationship between the incidence of melanoma and deprivation in New Zealand, a country with particularly high rates of the disease. In the light of greater public awareness of the risk factors associated with melanoma, through public awareness campaigns such as 'Slip! Slap! Slop' and 'No Suntan is Safe', we analyse small-area data on standardised rates of melanoma for the period 1995-2000. We found that melanoma rates increase with social status, even once other confounding factors are controlled for, but that the relationship is very small. Furthermore, the relationship between melanoma incidence and deprivation is context-dependent. Possible explanations for the relationship between melanoma and deprivation are discussed, including more frequent exposure to intermittent sunshine among less disadvantaged groups and the underreporting of melanoma incidence in the New Zealand cancer registry among individuals in lower social groups.