Source of funding and results of studies of health effects of mobile phone use: systematic review of experimental studies.
OBJECTIVE
There is concern regarding the possible health effects of cellular telephone use. We examined whether the source of funding of studies of the effects of low-level radiofrequency radiation is associated with the results of studies. We conducted a systematic review of studies of controlled exposure to radiofrequency radiation with health-related outcomes (electroencephalogram, cognitive or cardiovascular function, hormone levels, symptoms, and subjective well-being).


METHODS
We searched EMBASE, Medline, and a specialist database in February 2005 and scrutinized reference lists from relevant publications.


METHODS
Data on the source of funding, study design, methodologic quality, and other study characteristics were extracted. The primary outcome was the reporting of at least one statistically significant association between the exposure and a health-related outcome. Data were analyzed using logistic regression models.


RESULTS
Of 59 studies, 12 (20%) were funded exclusively by the telecommunications industry, 11 (19%) were funded by public agencies or charities, 14 (24%) had mixed funding (including industry), and in 22 (37%) the source of funding was not reported. Studies funded exclusively by industry reported the largest number of outcomes, but were least likely to report a statistically significant result: The odds ratio was 0.11 (95% confidence interval, 0.02-0.78), compared with studies funded by public agencies or charities. This finding was not materially altered in analyses adjusted for the number of outcomes reported, study quality, and other factors.


CONCLUSIONS
The interpretation of results from studies of health effects of radiofrequency radiation should take sponsorship into account.
Huss
Anke
A
Department of Social and Preventive Medicine, University of Berne, Berne, Switzerland.
Egger
Matthias
M
Hug
Kerstin
K
Huwiler-Müntener
Karin
K
Röösli
Martin
M
D040421:Cell Phone; D016265:Conflict of Interest; D004574:Electromagnetic Fields / Q000009:adverse effects*; D006801:Humans; D007221:Industry; D012109:Research Support as Topic