Abstract
Targeting of rheumatic heart disease (RHD) screening to those with the highest prevalence of Acute rheumatic fever (ARF) will increase the positive predictive value of the screening test and reduce the number needed to screen per definite RHD identified.
In order to maximise the efficacy of this targeting, we need to understand more regarding: a) which groups carry the highest burden of disease; b) where they reside; and c) how many people potentially comprise these target groups. For example, Māori and Pacific ethnicity are both strongly associated with ARF incidence independent of deprivation.
The current study aimed to update and build on previous work in this area by estimating the burden of ARF across multiple demographic and geographic strata. This required the achievement of the following objectives:
1) using literature review, summarise available data regarding the distribution of ARF in New Zealand by ethnicity, age, geographic region and deprivation (NZDep);
2) collect data from hospitalisations (National Minimum Dataset [NMDS], Ministry of Health) and national notifications (EpiSurv, Environmental Science and Research) on all new cases of ARF (2010-2013), including encrypted patient identifier (NHI) and all other available demographic information;
3) quantify the incidence (n) and distribution of ARF separately by geographic region, prioritised ethnicity, age group and deprivation level using census data as our denominator;
4) develop a risk prediction model for the New Zealand context which will allow us to simultaneously combine the effects of our predictors (e.g. ethnicity, deprivation, etc), and to identify groups who are most at risk (and therefore most likely to benefit from RHD screening);
5) using data from the 2013 census, quantify by geographic region the number of people who belong to the target ethnicity / age / deprivation groups (as identified from the risk prediction model).
The current brief report pertains to the first three of these objectives, while the final two objectives are the subject of a separate report.