Return on investment in needle and syringe programs in Australia: report

4.3 Impacts of NSPs on HIV and HCV

Page last updated: 2002

The impact of NSPs on HIV and HCV is presented in Section 3, and was prepared by the National Centre in HIV Epidemiology and Clinical Research, The University of New South Wales. Estimates of the number of HIV and HCV infections avoided through the introduction of NSPs by stage of disease are discussed in Section 3.4.4 and Section 3.5.4, with detailed figures for HIV and HCV contained in Table 3.4.5 and Table 3.5.5 respectively (See Appendix C).

Figure 4.2 and Figure 4.3 illustrate the estimated number of HIV and HCV cases with and without NSPs and the number of cases avoided, until all cases avoided have died.

In both instances, the figures illustrate that the total number of cases avoided accumulates up to the end of 2000, the end of the NSP investment period, then progressively decline as they progress through the various disease stages and mortality takes effect. The difference in scales of the two figures should be noted, reflecting the higher prevalence of HCV among IDUs.

Figure 4.4 and Figure 4.5 illustrate the stages of disease in HIV and HCV for the cases avoided by NSPs.

The figures illustrate the rate of progression of the two diseases, and the proportional distribution of the various stages of each disease over time, with later stages of the disease gaining greater prominence over time.

These data were applied in the economic model, with treatment costs included only for those patients diagnosed with the disease, as discussed in Section 3.4 and Section 3.5. To the extent that some consumers not diagnosed with the disease also incur costs of treatment, the exclusion of these consumers from the model represents a conservative approach (i.e. the costs of treatment avoided may be understated).

Figure 4.2 HIV cases with, without and avoided by NSPs

Text equivalent below for Figure 4.2 HIV cases with, without and avoided by NSPs
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Text version of Figure 4.2

Figures in this description are approximate as they have been read from the graph.

Figure 4.2 consists of three graphs:
  • HIV cases without NSPs:
    • Rises sharply from less than 1,000 in 1991 to about 26,000 in 2002
    • Gradually decreases from about 26,000 in 2002 to almost zero in 2072

  • HIV cases with NSPs: Decreases from less than 1,000 in 1991 to almost zero in 2072.

  • HIV cases avoided by NSPs:
    • Rises sharply from less than 1,000 in 1991 to about 26,000 in 2002
    • Gradually decreases from about 26,000 in 2002 to almost zero in 2072

Figure 4.3 HCV cases with, without and avoided by NSPs

Text equivalent below for Figure 4.3 HCV cases with, without and avoided by NSPs
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Text version of Figure 4.3

Figures in this description are approximate as they have been read from the graph.

Figure 4.3 consists of three graphs:
  • HCV cases with NSPs:
    • Sharply increases from about 110,000 in 1991 to about 225,000 in 2002
    • Gradually decreases from about 225,000 in 2002 to almost zero in 2078

  • HCV cases without NSPs:
    • Sharply increases from about 110,000 in 1991 to about 200,000 in 2002
    • Gradually decreases from about 200,000 in 2002 to almost zero in 2078

  • HCV cases avoided by NSPs:
    • Gradually rises from about 10,000 in 1991 to about 25,000 in 2002
    • Gradually decreases from about 25,000 in 2002 to almost zero in 2078

Figure 4.4 HIV cases avoided by stage of disease

Text equivalent below for Figure 4.4 HIV cases avoided by stage of disease
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Text version of Figure 4.4

Figures in this description are approximate as they have been read from the graph.

Figure 4.4 consists of four graphs:
  • Total cases:
    • Sharply rises from about zero in 1991 to about 25,000 in 2002
    • Gradually decreases from about 25,000 in 2002 to almost zero in 2072

  • Stage 1 cases:
    • Sharply rises from about zero in 1991 to about 19,000 in 2002
    • Sharply decreases from about 19,000 in 2002 to amost zero in 2015
    • Remains constant at about zero for subsequent years

  • Stage 2 cases:
    • Sharply rises from about zero in 1991 to about 16,000 in 2008
    • Gradually decreases from about 16,000 in 2008 to about zero in 2057
    • Remains constant at about zero for subsequent years.

  • AIDS cases:
    • Gradually rises from about zero in 1991 to about 3,000 in 2010
    • Gradually decreases from about 3,000 in 2010 to about zero in 2057
    • Remains constant at about zero for subsequent years

Figure 4.5 HCV cases avoided by stage of disease

Text equivalent below for Figure 4.5 HCV cases avoided by stage of disease
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Text version of Figure 4.5

Figures in this description are approximate as they have been read from the graph.

Figure 4.5 consists of four graphs:
  • Stage 0/1 cases avoided:
    • Steadily rises from about 4,000 in 1991 to about 14,000 in 2002
    • Gradually decreases from about 14,000 in 2002 to about zero in 2069
    • Subsequent years remain at a constant of about zero

  • Stage 2/3 cases avoided:
    • Gradually rises from about zero in 1991 to about 4,000 in 2030
    • Gradually decreases from about 4,000 in 2030 to about zero in 2069
    • Subsequent years will remain at a constant of about zero

  • Chirrhosis cases avoided:
    • Steadily rises from about zero in 1991 to about 3,000 in 2045
    • Gradually decreases from about 3,000 in 2045 to about zero in 2069
    • Subsequent years will remain at a constant of about zero

  • Total cases avoided:
    • Steadily rises from about 5,000 in 1991 to about 21,000 in 2002
    • Gradually decreases from about 21,000 in 2002 to about 16,000 in 2039
    • Steadily decreases from about 16,000 in 2039 to about zero in 2075
    • Subsequent years will remain at a constant of about zero

  • Non chronic cases avoided:
    • Steadily rises from about 1,000 in 1991 to about 5,000 in 2002
    • Slowly decreases from about 5,000 in 2002 to about 4,000 in 2042
    • Steadily decreases from about 4,000 in 2042 to about zero in 2069
    • Subsequent years will remain at a constant of about zero