Institute for Risk Assessment Sciences (IRAS), Utrecht University, PO Box 80178, 3508 TD Utrecht, the Netherlands.
Institute for Risk Assessment Sciences (IRAS), Utrecht University, PO Box 80178, 3508 TD Utrecht, the Netherlands.
Environ Res. 2018 Aug;165:150-157. doi: 10.1016/j.envres.2018.04.018. Epub 2018 Apr 26.
To study recall of mobile phone usage, including laterality and hands-free use, in young people.
Actual mobile phone use was recorded among volunteers aged between 10 and 24 years from 12 countries by the software application XMobiSense and was compared with self-reported mobile phone use at 6 and 18 months after using the application. The application recorded number and duration of voice calls, number of text messages, amount of data transfer, laterality (% of call time the phone was near the right or left side of the head, or neither), and hands-free usage. After data cleaning, 466 participants were available for the main analyses (recorded vs. self-reported phone use after 6 months).
Participants were on average 18.6 years old (IQR 15.2-21.8 years). The Spearman correlation coefficients between recorded and self-reported (after 6 months) number and duration of voice calls were 0.68 and 0.65, respectively. Number of calls was on average underestimated by the participants (adjusted geometric mean ratio (GMR) self-report/recorded = 0.52, 95% CI = 0.47-0.58), while duration of calls was overestimated (GMR=1.32, 95%, CI = 1.15-1.52). The ratios significantly differed by country, age, maternal educational level, and level of reported phone use, but not by time of the interview (6 vs. 18 months). Individuals who reported low mobile phone use underestimated their use, while individuals who reported the highest level of phone use were more likely to overestimate their use. Individuals who reported using the phone mainly on the right side of the head used it more on the right (71.1%) than the left (28.9%) side. Self-reported left side users, however, used the phone only slightly more on the left (53.3%) than the right (46.7%) side. Recorded percentage hands-free use (headset, speaker mode, Bluetooth) increased with increasing self-reported frequency of hands-free device usage. Frequent (≥50% of call time) reported headset or speaker mode use corresponded with 17.1% and 17.2% of total call time, respectively, that was recorded as hands-free use.
These results indicate that young people can recall phone use moderately well, with recall depending on the amount of phone use and participants' characteristics. The obtained information can be used to calibrate self-reported mobile use to improve estimation of radiofrequency exposure from mobile phones.
研究年轻人对手机使用情况的记忆，包括使用的侧别和免提使用情况。
通过 XMobiSense 软件，记录来自 12 个国家 10 至 24 岁志愿者的实际手机使用情况，并在使用该应用程序 6 个月和 18 个月后将其与自我报告的手机使用情况进行比较。该应用程序记录了语音通话次数和时长、短信数量、数据传输量、侧别（手机靠近头部左侧、右侧或两侧的时间百分比）和免提使用情况。在数据清理后，有 466 名参与者可用于主要分析（记录与自我报告的手机使用情况比较，6 个月后）。
参与者的平均年龄为 18.6 岁（IQR 15.2-21.8 岁）。记录与自我报告（6 个月后）的语音通话次数和时长的 Spearman 相关系数分别为 0.68 和 0.65。参与者平均低估了电话数量（经调整的几何平均比（GMR）自我报告/记录=0.52，95%CI=0.47-0.58），而通话时长则被高估（GMR=1.32，95%CI=1.15-1.52）。比值在国家、年龄、母亲教育水平和报告的手机使用水平方面存在显著差异，但在访谈时间（6 个月与 18 个月）方面没有差异。手机使用量低的报告者低估了他们的使用情况，而手机使用量最高的报告者更有可能高估他们的使用情况。报告主要使用手机右侧的人，其右侧使用手机的频率明显高于左侧（71.1%比 28.9%）。然而，自我报告的左侧使用者仅略高于右侧（53.3%比 46.7%）使用手机。记录的免提使用百分比（耳机、扬声器模式、蓝牙）随着自我报告的免提设备使用频率的增加而增加。高频（≥50%通话时间）报告的耳机或扬声器模式使用对应记录的 17.1%和 17.2%的总通话时间。
这些结果表明，年轻人可以适度回忆手机的使用情况，回忆取决于手机的使用量和参与者的特征。所获得的信息可用于校准自我报告的手机使用情况，以提高对手机射频暴露的估计。
