Table 1.

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

Studies	Country	No of cases	No of controls	Adjustments
Cohort or population based case-control studies:
Adam et al 198130	UK	169	207	Crude
Gallagher et al 198640*	Canada	595	595	—
Holman et al 198645	Australia	511	511	Crude
Osterlind et al 198851	Denmark	474	926	Not clear
Zanetti et al 198858	Italy	208	416	Age, hair colour, skin reaction, sunburn in childhood, education level
Beitner et al 199034*	Sweden	523	505	—
Walter et al 199055*†	Canada	583	608	—
Westerdahl et al 199457	Sweden	400	640	Hair colour, nevi, skin type, sunburns
Holly et al 199543	USA	452	930	—
Chen et al 199835	USA	624	512	Age, sex, phenotype, recreational sun exposure
Walter et al 199954	Canada	583	608	Age, sex, and skin reaction
Westerdahl et al 200056	Sweden	571	913	Sunburns, hair colour, sunbathing
Han et al 200642	USA	200	804
Clough-Gorr et al 200836	USA	423	678	Age, sex, family history, hair colour, sun exposure
Cust et al 201137	Australia	604	479	—
Lazovich et al 201047	USA	1167	1101	Age, sex, family history, hair colour, sun exposure
Veierød et al 201014	Norway, Sweden	412	106 366‡	Age, residence, hair colour, sunburns, annual “bathing” holiday
Elliott et al 201139	UK	959	513	Age, sex, educational level, family history of melanoma, sun sensitivity, and sun exposure
Nielsen et al 201150	Sweden	210	29 520‡	Crude
Zhang et al 201259	USA	349	73 494‡	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*	Norway	78	131	—
Holly et al 198744*	USA	121	139	—
Swerdlow et al 198852	UK	180	120	Crude
MacKie et al 198948	UK	280	180	Nevi, skin type, sunburn, freckles, tropical residence
Dunn-Lane et al 199338	UK	100	100	Crude
Garbe et al 199341	Germany	280	280	Nevi, hair type, and phototype§
Autier et al 199431	Multicentre	420	447	Crude
Naldi et al 200049	Italy	542	538	Age, sex, skin, hair, eye, nevi, freckles, sunburns, number of holidays in sunny climates
Kaskel et al 200113	Germany	271	271	Crude
Bataille et al 200433	UK	413	416	Sex and age
Bataille et al 200532	Belgium, France, Netherlands, Sweden, UK	597	622	Sex, age, and skin phototype§
Ting et al 200753	USA	29	307	Not 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.