How accurate are Townsend Deprivation Scores as predictors of self-reported health? A comparison with individual level data.

OBJECTIVES: To determine the accuracy of area based Townsend Deprivation Scores (TDSs) as proxies for individual level deprivation and to compare the ability of TDSs and individual level measures of deprivation to predict selfreported health.
METHODS: Using data from a self completed health and behaviour survey sent to a random sample of households in Newcastle upon Tyne, UK, the ability of TDSs, calculated at the enumeration district and ward level, to predict selfreported health was compared to that of an individual level measure of deprivation similar to TDSs. The correlation between each of these measures of deprivation was also investigated.
RESULTS: Enumeration district TDSs were similarly predictive of self-reported health as the individual level measure of deprivation. Ward-level TDSs showed a much weaker association with self-reported health. Although statistically significant, no deprivation measure accounted for more than 3 per cent of the variation in self-reported health. There was a strong correlation between the individual level measure of deprivation and enumeration district, but not ward-level TDSs.
CONCLUSIONS: TDSs calculated at the enumeration district level are strongly correlated with a similar measure of deprivation calculated at the individual level and are similarly predictive of health. This is not the case for TDSs calculated at the ward level. Enumeration district TDSs are good proxies for individual level deprivation in Newcastle upon Tyne. This may not be the case in more mobile populations.