Cell phone use and behavioural problems in young children

Abstract

The findings of the previous publication were replicated in this separate group of participants demonstrating that cell phone use was associated with behavioural problems at age 7 years in children, and this association was not limited to early users of the technology. Although weaker in the new dataset, even with further control for an extended set of potential confounders, the associations remained.

Complexities of sibling analysis when exposures and outcomes change with time and birth order

“…To demonstrate that associations between cell phone exposure and behavioral problems were not limited to early adopters of technology and persisted in the new sample after adjustment for several additional potential confounders, the authors replicated their findings in a separate group of 28,745 children from the same cohort. 6 Although the authors did not find evidence of confounding by measured factors, the possibility that confounding by unmeasured social, environmental, and hereditary factors may explain the observed associations could not be ruled out. An analysis that compares siblings in the DNBC may help to resolve some of the problems of unmeasured confounding.…”

“…This analysis is based on data from 52,680 children from singleton births included in the age-7 questionnaire. The data set consists of children included in the previous studies by Divan et al, 5,6 plus 11,139 for whom data were coded after completion of the previous analyses. About 10% (n ¼ 5441) of these children had at least one sibling from a singleton birth also included in this data set.…”

“…7 These cutoff points were based on population-based norms and were included with the SDQ algorithm when this study was conducted. They were the same cutoff points as those used by Divan, et al 5,6 From prenatal and postnatal interviews, the DNBC has also collected information from mothers regarding parity, social-occupational factors, history of psychiatric illness, smoking, and breastfeeding. Additional data were obtained by linking each mother and child to Danish national social and medical registers.…”

“…3 Conversely, another investigation did not detect an association between prenatal cell phone use and behavioral problems in children, albeit this study was based on a small sample size, particularly a small number of exposed cases. 4 Two analyses conducted among children in the Danish National Birth Cohort (DNBC) by Divan et al 5,6 in 2008 and 2010 reported associations between prenatal and postnatal cell phone exposures and behavioral problems at age 7. Overall behavioral problems and specific behavioral outcomes were assessed using the Strengths and Difficulties Questionnaire (SDQ).…”

“…For example, trends of increasing cell phone use and changes in cell phone technology over time could have contributed to the results observed by Divan et al 5,6 The DNBC enrolled pregnant women during a time when cell phones were rapidly gaining popularity and many women were just beginning to use them. Children born earlier in the cohort are, therefore, less likely to have been exposed prenatally than those born later.…”