Table 5.

Results of case–case analyses of glioma and meningioma by time since start of use of mobile phones and cumulative call time comparing cases^* originating in the region of the brain within the 3 dB exposure volume (∼16% of brain volume receiving 50% of the total absorbed energy) to cases^† originating in other areas of the brain^‡

	Glioma			Meningioma
	Centre within most exposed area*	Centre outside most exposed area†	OR (95% CI)	Centre within most exposed area*	Centre outside most exposed area†	OR (95% CI)
Regular user
Never regular user	14	178	1.00	66	221
Ever regular user	30	334	1.35 (0.64 to 2.87)	69	316	0.74 (0.49 to 1.11)
Time since start of use (years)
Never regular user	14	178	1.00	66	221	1.00
1–4	12	133	1.37 (0.59 to 3.19)	38	179	0.67 (0.41 to 1.07)
5–9	7	147	0.72 (0.27 to 1.90)	22	112	0.75 (0.42 to 1.34)
10+	11	54	2.80 (1.13 to 6.94)	9	25	1.34 (0.55 to 3.25)
Cumulative call time without hands-free devices (h)
Non-regular	14	178	1.00	66	221	1.00
<39	6	65	1.19 (0.40 to 3.51)	16	97	0.55 (0.29 to 1.02)
39–	4	67	0.93 (0.27 to 3.14)	21	78	0.93 (0.51 to 1.68)
220–	5	68	1.38 (0.42 to 4.53)	9	52	0.52 (0.23 to 1.14)
520–	10	66	2.55 (0.94 to 6.91)	10	52	0.67 (0.30 to 1.48)
1147+	5	68	0.99 (0.30 to 3.27)	13	37	1.41 (0.66 to 3.02)

^*Treated as ‘cases’.

^†Treated as ‘controls’.

^‡Quintiles of cumulative call time among ‘controls’ (glioma cases with tumour centre outside the most exposed area). Centre is as estimated by a neuroradiologist when available or as estimated by computer algorithm otherwise. Unconditional logistic regression analyses were done, stratified on age, sex and region and adjusted for education and timing of interview.