Burden and Cost of Rheumatic Fever and Rheumatic Heart Disease in New Zealand: Focus on School Age Children A Report to the Ministry of Health.

Abstract

Background: Acute rheumatic fever (ARF) is a preventable inflammatory disease which can develop after pharyngitis caused by group A streptococcus (GAS) bacteria. The most severe sequela is rheumatic heart disease (RHD) with mitral and/or atrial valve regurgitation. A school intervention is now available which is likely to reduce the ARF incidence rate by about 60%. In order to achieve value for money it is necessary to target the intervention to the highest risk children. The purposes of this study were: (1) to estimate ARF incidence rates for primary and intermediate school age children by region, ethnicity and socioeconomic deprivation, to inform targetting of the intervention; and (2) to estimate annual costs of ARF and RHD hospital admissions to the NZ Government, to inform a full economic evaluation of a school intervention. Methods: National hospital admissions with a principal diagnosis of ARF or RHD (ICD9_AM 390-398; ICD10-AM I00-I099) for the period January 1993 to December 2009 were obtained from the National Minimum Data Set. Index (first-ever) admissions were stratified by 5-year age group, prioritised ethnicity, (M ori, Pacific, European/Other), NZ deprivation index (NZDep2006) and District Health Board (DHB). The cost of each ARF or RHD admission in the period 2000-2009 was obtained from its diagnosis related group (DRG) cost weight. Deaths with an underlying cause of RHD for the period January 1993 to December 2007 were obtained from the National Mortality Collection. Population denominators were NZ Census prioritised ethnicity.