Table 3. ARCH – IDU Risk Scoring Sheet.

1	How old are you today (years)?	If <30 years,	score 38			―――――――――
		If 30- 39 years,	score 24
		If 40-49 years,	score 7
		If ≥50 years,	score 0
2	In the last 6 months, were you in a methadone maintenance program?	If yes,	score 0			―――――――――
		If no,	score 31
3	In the last 6 months, how often did you inject heroin?	If 1 or more times,	Injection sub-score 1		―――――――――
		If 0 times,	Injection sub-score 0
	In the last 6 months, how often did you inject cocaine?	If 1 or more times,	Injection sub-score 1		―――――――――
		If 0 times,	Injection sub-score 0
	In the last 6 months, how often did you share a cooker?	If 1 or more times,	Injection sub-score 1		―――――――――
		If 0 times,	Injection sub-score 0
	In the last 6 months, how often did you share needles?	If 1 or more times,	Injection sub-score 1		―――――――――
		If 0 times,	Injection sub-score 0
	In the last 6 months, how often did you visit a shooting gallery?	If 1 or more times,	Injection sub-score 1		―――――――――
		If 0 times,	Injection sub-score 0
	Composite Injection Score			Add down the 5 injection subscores above		―――――――――
				If 0,	score 0
				If 1,	score 7
				If 2,	score 21
				If 3,	score 24
				If 4,	score 24
				If 5,	score 31
				Add down the three entries in the right column to calculate total score		――――――――― TOTAL SCORE*

^†To identify active IDU in their practice, we recommend clinicians ask all their patients a routine question: “Have you ever injected drugs that were not prescribed for you by a physician” (if yes), “When was the last time you injected any drugs?” Only complete IDU risk index if they have injected any nonprescription drug in the past 6 months.

^*If score is 46 or greater, evaluate for PrEP or other intensive HIV prevention services for IDU.

If score is 45 or less, provide indicated standard HIV prevention services for IDU.