Table 1 Values, notes, and sources for variables used to predict HIV infection reduction savings

Proportion of PWID HIV− (I)

82.30%

Mehta [6]

Number of needles in circulation (N)

1,600,000

Increased by 33% due to additional syringe sources

Hunt and Parker [81];German et al. [82]

Rate of needle sharing (s)

2.8%

Percent of injections with a needle already used by another person

Park et al. [83]

Percentage of needles not bleached (d)

100%

Bluthenthal et al. [84]

Proportion of PWID HIV+ (q)

17.70%

Mehta [6]

Probability of HIV infections from a single injection (t)

0.67%

Kaplan and O’Keefe [85]; Kwon et al. [86]

Number of sharing partners (m)

1.2

Per injection: ratio of receptive to distributive sharing

Park et al. [83]

SIF client reduction in needle sharing (n)

70%

From Insite

Kerr et al. [40]

Number of SIF clients (N)

2100

Approximate monthly unique Insite injection room clients

Maynard [33]

PWID Population (T)

20,950

Adjusted by authors from Baltimore MSA to City using race census data

Tempalski et al. [87]

Lifetime HIV treatment cost

$402,000

National data

CDC [88]