Table 1

Comparison of miners by inclusion in the analysis and by HIV status

	Included in analysis							No records of time off
Factor	HIV-positive		HIV-negative			Total		No records of time off
Factor	n	%	n	%	p Value^*	n	%	n	%	p Value^†
Total	1703		4859			6562		1202
Age (years) at start of study					<0.001					<0.001
15–24	264	15.5	555	11.4		819	12.5	117	9.7
25–34	966	56.7	2466	50.8		3432	52.3	475	39.6
35–44	395	23.2	1433	29.5		1828	27.9	257	21.4
45+	78	4.6	405	8.3		483	7.4	352	29.3
South African	835	49.0	2523	51.9	0.04	3358	51.2	636	53.0	0.26
Calendar year of study recruitment					<0.001					<0.001
≤1992	426	25.0	1816	37.4		2242	34.2	450	37.4
1993	338	19.9	3043	62.6		3381	51.5	634	52.8
1994+	939	55.1	0	0		939	14.3	118	9.8
Still employed in 2002	444	26.1	1855	38.2	<0.001	2299	35.0	110	9.2	<0.001
HIV-positive	–		–			1703	26.0	247	20.6	<0.001
Median (IQR) study follow-up, years	4.9 (2.5 to 7.0)		6.6 (4.0 to 9.4)		<0.001	6.0 (3.3 to 9.3)		4.8 (2.5 to 5.9)		<0.001
Median (IQR) follow-up, years (primary analysis)	3.4 (1.9 to 5.6)		5.4 (3.2 to 9.3)		<0.001	5.0 (2.5 to 8.7)