Table 4. Characteristics of the studies presenting incidence rate of switching to second-line ART.

	Year of beginning of follow-up	Year of end of follow-up	% women	Median age at baseline	Median CD4 count at baseline	% with WHO stage4 condition atbaseline	% with WHO stage3–4 conditionat baseline	Viral loadmonitoring
Orrell et al. [16]	2002	2005	72.2	33	95	27.5	81	Every 4 months
Pujades-Rodriguez et al. [17]	2001	2006	NA	NA	NA	NA	NA	Targeted
Palombi et al. [18]	2002	2007	62.0	34	192	NA	37	Every 6 months
DART trial team - LCM [19]	2003	2008	66.0	36	86	23	78	None
DART Trial Team - CDM [19]	2003	2008	64.0	36	86	24	81	None
Keiser et al. [20]	1998	NA	72.0	35	128	NA	50.5	Routine in 3 of 7 programmes (9.1% of all patients)
Landier et al. [21]	2003	2008	62.1	34	124	23	84	None
Auld et al. [22]	2004	2008	60.7	34	155	15	60	None
Keiser et al. –With viral load monitoring [23]	NA	NA	65.7	35	93	NA	57.7	Every 3–6 months
Keiser et al. – No viral load monitoring [23]	NA	NA	61.8	36	132	NA	70.7	Limited access**
Laurent et al. – LCM arm [8]	2006	2010	71	37	182	26	100	Every 6 months
Laurent et al. – CDM arm [8]	2006	2010	70	36	179	26	99	None

^**as stated in the article.

NA: not available.