DAMASCENE and Meta-Ecological Research: A Bridge Too Far.

P opulation level studies commonly induce the ecological fallacy, that is, the belief that a relationship identified at the population level implies a cause-and-effect relationship at the level of the individual. A recent research report (DAMASCENE [discrepancies in autologous bone marrow stem cell trials and enhancement of ejection fraction]) that related clinical trial effect sizes in cardiovascular cell therapy trials to reporting discrepancies in the trials themselves has compounded difficulties in meta-analysis with ecological fallacy issues. This dangerous combination has produced misleading conclusions and speculation that the research community should set aside. The data tell us that the incident stroke rate has increased in the 20-to 54-age group from 26 to 48 cases per 100 000 for a 10-year period. 1 During this time, the use of cell phone, particularly smartphone, has increased from near 0 to >50%. 2 Although there have been concerns about the relationship between electromagnetic emissions of portable phones and brain cancer for years, this is the first time that a temporal correlation has been identified between the newer smart phones and the chronic disease. The implications have immense health and financial consequences. The implications are also false. This is an example of a spurious relationship residing within a population-based study, which is known as an ecological fallacy. The ecological fallacy is the belief that one can take population level correlations and transfer them to cause-and-effect relationships within the individual. 3 In this example, what may be driving stroke incidence in these younger populations is the rising rate of obesity and diabetes mellitus. On the other hand, smartphone purchases can be motivated by declining prices, the attractiveness of a sleek device, and the desire for social connectivity. The population-level smartphone–stroke relationship does not represent what is occurring at the level of the individual where motivations for smartphone purchases and the drivers of cerebrovascular disease are different. To think that the population-level relationship can be successfully transferred to the individual is the nature of the ecological fallacy (other examples of temporal ecological fallacies may be found at http://www.tylervigen.com). In this artificial case, we can see through the diaphanous population-level relationship to get to the heart of the matter because we have a solid a priori sense of the reasons that motivate smartphone purchases and the causes of strokes. This understanding permits us to hold the conclusory statement that smartphone use causes stroke at bay as we think …