Table 1

 Characteristics of studies on sunbed use and melanoma considered for meta-analysis

StudiesCountryNo of casesNo of controlsAdjustments
Cohort or population based case-control studies:
 Adam et al 198130UK169207Crude
 Gallagher et al 198640*Canada595595
 Holman et al 198645Australia511511Crude
 Osterlind et al 198851Denmark474926Not clear
 Zanetti et al 198858Italy208416Age, hair colour, skin reaction, sunburn in childhood, education level
 Beitner et al 199034*Sweden523505
 Walter et al 199055*†Canada583608
 Westerdahl et al 199457Sweden400640Hair colour, nevi, skin type, sunburns
 Holly et al 199543USA452930
 Chen et al 199835USA624512Age, sex, phenotype, recreational sun exposure
 Walter et al 199954Canada583608Age, sex, and skin reaction
 Westerdahl et al 200056Sweden571913Sunburns, hair colour, sunbathing
 Han et al 200642USA200804
 Clough-Gorr et al 200836USA423678Age, sex, family history, hair colour, sun exposure
 Cust et al 201137Australia604479
 Lazovich et al 201047USA11671101Age, sex, family history, hair colour, sun exposure
 Veierød et al 201014Norway, Sweden412106 366‡Age, residence, hair colour, sunburns, annual “bathing” holiday
 Elliott et al 201139UK959513Age, sex, educational level, family history of melanoma, sun sensitivity, and sun exposure
 Nielsen et al 201150Sweden21029 520‡Crude
 Zhang et al 201259USA34973 494‡Age, family history, hair colour, number of moles, sunburn tendency and history, outdoor sun exposure, ultraviolet index, state of residence at birth, age 15, and age 30
Other case-control studies:
 Klepp and Magnus 197946*Norway78131
 Holly et al 198744*USA121139
 Swerdlow et al 198852UK180120Crude
 MacKie et al 198948UK280180Nevi, skin type, sunburn, freckles, tropical residence
 Dunn-Lane et al 199338UK100100Crude
 Garbe et al 199341Germany280280Nevi, hair type, and phototype§
 Autier et al 199431Multicentre420447Crude
 Naldi et al 200049Italy542538Age, sex, skin, hair, eye, nevi, freckles, sunburns, number of holidays in sunny climates
 Kaskel et al 200113Germany271271Crude
 Bataille et al 200433UK413416Sex and age
 Bataille et al 200532Belgium, France, Netherlands, Sweden, UK597622Sex, age, and skin phototype§
 Ting et al 200753USA29307Not clear

*Not included in main meta-analysis as no estimate of risk was reported.

†1990 study was reanalysed in 1999. Present meta-analysis uses relative risk adjusted for potential confounders presented in 1999 publication.

‡Cohort size.

§Sensitivity to sunlight.