Table 7.

Sensitivity, specificity and positive and negative predictive values of three-item adherence scale predicting viral load ≥50 and ≥1000 copies/mL, using a scale cut-off score of <80, <90 and <100

	Viral load		Sensitivity (%)	Specificity (%)	Positive predictive value (%)	Negative predictive value (%)
Adherence (three-item scale score)	Detectable (≥50)	Non-detectable (< 50)
Non-adherent (<80)	28	97	36	74	22	85
Adherent (≥80)	50	277
	Detectable (≥50)	Non-detectable (< 50)
Non-adherent (<90)	58	224	74	40	21	88
Adherent (≥90)	20	150
	Detectable (≥50)	Non-detectable (< 50)
Non-adherent (<100)	73	324	94	13	18	91
Adherent (100)	5	50
	Detectable (≥1000)	Non-detectable (< 1000)
Non-adherent (<80)	17	108	45	74	14	94
Adherent (≥80)	21	306
	Detectable (≥1000)	Non-detectable (< 1000)
Non-adherent (<90)	29	253	76	39	10	95
Adherent (≥90)	9	161
	Detectable (≥1000)	Non-detectable (< 1000)
Non-adherent (<100)	37	360	97	13	9	98
Adherent (100)	1	54