Table 3.

Switches to Second-Line Antiretroviral Therapy after 6 to 48 Months of First-Line Antiretroviral Therapy

Months on Antiretroviral Therapy	Cohorts, N		Participants, N (at baseline)				Descriptive Statistics			Random-Effects Meta-analysis
	Total	% of Studies from Intention-to-Treat Analysis	Total	Median	Interquartile Range		Median	Interquartile Range		Summary Estimate	95% Confidence Interval		τ2a
					Q1	Q3		Q1	Q3		Low	High
6	22	55.0	24 451	67	27	382	0.0	0.0	0.0	1.7	1.0	2.5	0.09
12	25	37.3	19 923	230	61	596	0.0	0.0	1.4	1.6	1.1	2.1	0.12
24	12	52.2	7100	283	104	701	0.3	0.0	3.1	1.7	0.7	2.6	0.02
36	3	75.0	2407	1009	328	1070	6.1	3.6	7.0	5.4	3.3	7.5	0.01
48	2	50.0	595	298	80	515	10.1	7.8	12.5	9.2	4.8	13.6	0.01

^a τ² is a measure of between-study heterogeneity that is less affected by the number of studies than other common measures.