Table 1.

Study settings and sample size

Level	Settings	Site name	Type of services	Sample size
District (urban)	Nam Dinh City	Provincial AIDS Centre	MMT + VCT	270
District (rural)	Xuan Truong District	District Health Centre	MMT + VCT + ART + GH	151
District (urban)	Tu Liem District	District Health Centre	MMT + VCT + ART + GH	201
District (urban)	Long Bien District	District Health Centre	MMT + VCT + ART + GH	184
District (urban)	Ha Dong District	Regional Polyclinic	MMT+ GH	210

ART, antiretroviral therapy; GH, general healthcare; MMT, methadone maintenance treatment; VCT, voluntary counselling and testing.