These researchers applied modelling techniques to assess the distribution of seasonal influenza-attributable mortality in New Zealand by ethnicity and socioeconomic status (SES). Quasi Poisson regression models were populated with weekly counts of deaths and isolates of influenza A, B and respiratory syncytial virus covering the period 1994 through 2008. SES was derived from the New Zealand Deprivation Index (NZDep). The estimated average mortality rate was 13.5 per 100,000 people, totalling 1.8% of all deaths in New Zealand. Influenza mortality differed markedly by age, sex, ethnicity and SES. Relatively vulnerable groups were males aged 65–79 years (rate ratio [RR] 1.9; 95% CI, 1.9 to 1.9, reference females), Māori (RR 3.6; 95% CI, 3.6 to 3.7, reference European/Others aged 65–79 years), Pacific (RR 2.4; 95% CI, 2.4 to 2.4, reference European/Others aged 65–79 years) and those living in the most deprived areas (RR 1.8; 95% CI, 1.3 to 2.4) for NZDep 9&10 (the most deprived) compared with NZDep 1&2 (the least deprived).
