5  Disaggregating the Data – Results from Individual Procedures, DHBs and Hospitals

Disaggregating the data allows us to look at the individual procedures across different DHBs and hospitals. This is particularly useful for examining the extent to which populations in each region have access to both new and well established technologies.

5.1.1  Maori and Pacific Island people are not well represented in the sample but the ethnicity mix is changing over time for certain regions.

The aggregate data suggest that ethnic groups other than NZ European are underrepresented. However, the disaggregated data provide a richer story. Table 7 decomposes stent procedures (i.e. a new technology) for each DHB based on patient age, gender, and ethnicity. Figures for Auckland, Canterbury and Waikato show a reduction in the proportion of patients who are NZ European with figures for the remaining DHBs showing no significant change.

Note: Gender refers to the percentage of males in the sample receiving a stent Ethnicity refers to the percentage of stent recipients who describe themselves as NZ European.

5.1.2  Access to the new technology varies according to ethnicity and where you live…

Appendix Tables 2 and 3 (attached) standardise the number of stent procedures for patients per 1000 of the population based on their domicile DHB. Appendix Table 2 shows the cumulative figure of stent procedures for the period 1995-2004 whereas the Appendix Table 3 provides the last complete year of data (2003). This raises several important points. First, when looking at the cumulative figures for stents, the standardised number of stents for Maori and Pacific Island people consistently falls short of that of NZ Europeans. Furthermore, this disparity is at its greatest for people living in DHBs in the South Island. However, when 2003 data is taken in isolation, these disparities narrow. One would not want to put a large weight on this particular point given that the analysis is based on small numbers and is not standardised for age. For instance, the total population of DHBs on the South Island is 906 744 with Maori and Pacific Island people constituting just 79 533 i.e. 8.77% of the population. A much higher proportion of the Maori and Pacific Island populations is younger than 20, than of the NZ European population so one would expect a lower rate of cardiac procedures compared with NZ Europeans. Nevertheless, it is worth flagging at this stage.

5.1.3  Access to a well established technology also varies according to ethnicity and domicile DHB. 

Appendix Tables 4 and 5 (attached) standardise the number of CABGs for patients per 1000 of the population based on their domicile DHB. Appendix Table 4 shows the cumulative figure of CABGs for the period 1995-2004 with Appendix Table 5 showing the last complete year of data (2003). As with stents, disparities exist between ethnic groups. However, these are equally large across the entire country. When looking at the 2003 data alone, there are domicile DHBs in which the standardised number of CABGs is the same or greater for the Maori and Pacific Island community than for the NZ Europeans (Northland, Auckland, Capital and Coast, South Canterbury and Southland). Again, this is based on small numbers and data that has not been age standardised but is worth noting and monitoring for future years since this may suggest that balance is being redressed.

5.1.4  The new technology is most likely to be found in hospitals where patient volume is high and where there are teaching and research links…

In tracing the spread of the new technology, Table 8 shows the district health boards in which stents have been performed and the number of admissions. Clearly this is dominated by the “Big 5” but there are other smaller DHBs which have also at some stage offered the procedure.

Table 8 – The Number of Admissions for Stent Procedure

Table 9 breaks the admission numbers down by year and hence shows the dispersal of the technology. This shows that the pioneers were Auckland, Capital and Coast, Otago and Waikato in 1995 with Christchurch following suit in 1998. Closer examination shows the hospitals that were responsible.

Appendix Table 6 provides an interesting story. Clearly, a number of Auckland hospitals have used the technology (National Womens, Greenlane, Auckland and Auckland City). However, Auckland City Hospital opened in 2003 and brought together the services of Auckland, Greenlane and National Womens Hospitals into one building. The general trend in the DHB has been a steady increase in this procedure. The other main facilities have been Wellington, Waikato, Dunedin and Christchurch Hospitals and these have also seen an increase in stenting.

Table 9 – No. of Stents Performed in each District Health Board