Appendix D: Estimating Necessary Syringe And Supply Quantities
Excerpted from Guide To Starting And Managing Needle And Syringe Programmes WHO/UNAIDS
STOCK ORDERS, STORAGE, AND DISPOSAL
It may be difficult to estimate how many needles and syringes will be needed in the first year owing to unknown factors. Unknowns may include the time needed to establish the location of the programme, recruit staff and satisfy the regulatory requirements of city authorities and police; the time needed to contact and recruit injecting drug users to the service (this varies widely from place to place); and seasonal variations in demand for injecting equipment.
To arrive at a figure, the results of a rapid assessment and response survey (RAR) can be used to estimate the target number of injecting drug users to be reached on a regular basis (at least monthly) by the 12th month of the project: a useful rule-of-thumb is that 10% should be reached in this way by this time. This means that, in a city with 10,000 injecting drug users, the NSP should be accessed by at least 1000 on a regular basis by the end of its first year. If the NSP is to be effective in changing behaviours, each of these regular clients should be receiving at least three needles and syringes per week (or an average of 3000 needles and syringes per week). The estimation process for an NSP in the above situation would therefore look something like:
Months 1-3 (set-up phase): 0 per week: 0
Months 4-6 (initiation phase): 500 per week average x 13 weeks: 6500
Months 7-9: 1500 per week average x 13 weeks: 19,500
Months 10-12: 2500 per week on average x 13 weeks1: 32,500
Annual estimate (first year): 58,500
It should be noted that these calculations, though based on the experience of setting up NSPs in many countries, are not applicable for every situation. For example, in districts with fewer than 1000 injecting drug users, some programmes have been able to gain access to 40% or more of drug injectors by month 12. Also, the figure of three needles and syringes per regular client per week is not optimal. Many guides and government strategies on needle and syringe provision state that the target is to provide every injecting drug user with sterile injecting equipment for every injection. This is to be applauded but even the largest NSP systems in the world have not yet been able to attain this goal. As well, keep in mind that this calculation process is only for the first year. Over time, many more injecting drug users should be reached on a regular basis and the number of needles and syringes distributed per client should increase.
While the NSP should be providing at least 3000 needles and syringes per week under this model by month 12, it is still building towards that figure in months 10 and 11: hence the lower average across the three months of 2500 needles and syringes per week.