Background: Ill-health has been linked to poverty and deprivation. Many factors determine the extent of disadvantage of one person over another, the most important including relative income, education, employment, housing/living conditions, social and family circumstances. In many instances, it is the same group of individuals in society who are coping with several of these problems simultaneously.

Methods: The study population (n = 1387) consisted of all paracetamol overdose patients who had attended A&E departments at five Belfast hospitals in the Eastern Health and Social Services Board (EHSSB) during 1998/1999. At three of the sites, data were collected over a 12 month period whilst at the other two sites data were collected over an 18 month period. All study patients were mapped according to their postcode (where possible), and assigned a Noble multiple deprivation score, based on data obtained from Ordinance Survey of Northern Ireland (OSNI) and the Northern Ireland Statistics and Research Agency (NISRA) respectively.

Results: Of the 1387 cases of paracetamol overdose recorded in the study, 1145 postcodes were available for mapping. This 'drop-out' was due to study patients having no address recorded, being of no fixed abode, having postcodes that had not been geo-coded on the OSNI system or residing outside the EHSSB area. Paracetamol overdose patients attending A&E departments at the five study hospitals were distributed over 132 wards. The sex distribution of paracetamol overdose patients studied was markedly different to that of the EHSSB population (60% female in the study population compared to 51% in the EHSSB population). Similarly, patients aged 10 - 39 years accounted for 80% of all paracetamol overdose cases recorded, compared with 46% of the EHSSB population. Paracetamol overdose patients were distributed widely over the EHSSB area. There were, however, pockets where paracetamol overdose appeared to be more profuse. Generally, higher rates of paracetamol overdose were observed in wards with higher multiple deprivation indices. For example, Ballymacash had a rate of paracetamol overdose of 23:100,000 population, whereas Shaftesbury had a rate of 638:100,000 population. A comparison of the rate of paracetamol overdose in wards across the EHSSB with the ward multiple deprivation index highlighted that the mean rate of paracetamol overdose (± SD) was 209 (± 150) persons per 100,000 of the population. The R2 value was calculated as 0.42, which means that 42% of the variability in the rate of paracetamol overdose was accounted for by the change in multiple deprivation index.

Conclusion: Ward populations with the highest frequencies of paracetamol overdose had the highest rates of unemployment, chronic ill-health or disability, religious segregation, births to unmarried mothers, hospital attendance and State benefits being claimed. They also had the lowest rates of home ownership, access to transport and educational attainment. The rate of paracetamol overdose was positively correlated with deprivation at ward level as determined by the Noble multiple deprivation index.