Syringe Stockpiling by Persons Who Inject Drugs: An Evaluation of Current Measures for Needle and Syringe Program Coverage.

Needle and syringe program (NSP) coverage is commonly used to assess NSP effectiveness. However, existing measures don't capture whether persons who inject drugs (PWIDs) stockpile syringes, an important and novel aspect of NSP coverage. In this study, we determine the extent of stockpiling in a sample of Australian PWIDs and assess whether including stockpiling enhances NSP coverage measures.