Source of Funding and Results of Studies of Health Effects of Mobile Phone Use: Systematic Review of Experimental Studies

摘要

OBJECTIVES: 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).DATA SOURCES: We searched EMBASE,Medline,and a specialist database in February 2005 and scrutinized reference lists from relevant publications.DATA EXTRACTION: 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.DATA SYNTHESIS: 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.