Table 3. Relative risk of lung cancer, by markers of immunodeficiency at two different time periods before cancer diagnosis.

	One to two years before lung cancera						Within one year before lung cancera
	Lung cancer		Controls				Lung cancer		Controls
	N	%	N	%	ORb (95% CI)	Smoking-adjusted ORc (95% CI)	N	%	N	%	ORb (95% CI)	Smoking-adjusted ORc (95% CI)
Overall	68		337				68		337
CD4+ cell count, cells per μl
⩾500	23	39.0	100	34.2	1	1	20	29.4	119	36.4	1	1
200–499	26	44.1	146	50.0	0.76 (0.41–1.43)	0.59 (0.30–1.16)	38	55.9	159	48.6	1.41 (0.78–2.54)	1.11 (0.59–2.10)
<200	10	16.9	46	15.8	0.96 (0.41–2.24)	0.97 (0.40–2.34)	10	14.7	49	15.0	1.21 (0.49–2.96)	1.19 (0.47–3.04)
Unknown	9		45				0		10
CD8+ cell count, cells per μl
⩾1000	28	47.5	122	41.9	1	1	26	38.2	132	40.4	1	1
500–999	25	42.4	128	44.0	0.84 (0.46–1.53)	1.05 (0.55–1.98)	35	51.5	156	47.7	1.15 (0.65–2.05)	1.11 (0.60–2.04)
<500	6	10.2	41	14.1	0.64 (0.25–1.67)	0.57 (0.20–1.58)	7	10.3	39	11.9	0.92 (0.37–2.29)	0.77 (0.30–1.97)
Unknown	9		46				0		10
CD4+/CD8+ ratio, %
⩾0.50	25	42.4	125	43.0	1	1	22	32.4	140	42.8	1	1
0.25–0.49	22	37.3	109	37.5	1.01 (0.53–1.90)	0.78 (0.39–1.55)	26	38.2	120	36.7	1.38 (0.74–2.57)	1.14 (0.58–2.23)
<0.25	12	20.3	57	19.6	1.07 (0.49–2.36)	0.92 (0.40–2.09)	20	29.4	67	20.5	2.15 (1.00–4.59)	2.12 (0.94–4.77)
Unknown	9		46				0		10
HIV viral load, copies per ml
<500	37	68.5	192	71.4	1	1	40	72.7	207	74.5	1	1
500–9999	12	22.2	36	13.4	1.79 (0.83–3.86)	2.05 (0.90–4.67)	8	14.5	37	13.3	1.15 (0.49–2.70)	1.27 (0.50–3.21)
⩾10 000	5	9.3	41	15.2	0.66 (0.24–1.79)	0.44 (0.15–1.29)	7	12.7	34	12.2	1.10 (0.44–2.75)	0.81 (0.32–2.07)
Unknown	14		68				13		59

Abbreviations: CI=confidence interval; OR=odds ratio.

^aOr before the reference date in controls (see the ‘Materials and Methods’ section for definition).

^bConditioned upon matching variables.

^cConditioned upon matching variables and adjusted for smoking (never/former, current with <30 pack-years, current with ⩾30 pack-years, unknown).