title: Long-term recall accuracy for mobile phone calls in young Japanese people: A follow-up validation study using software-modified phones.
abstract: This study examined changes in recall accuracy for mobile phone calls over a long period. Japanese students' actual call statuses were monitored for 1 month using software-modified phones (SMPs). Three face-to-face interviews were conducted to obtain information regarding self-reported call status during the monitoring period: first interview: immediately after the monitoring period; second interview: after 10-12 months; third interview: after 48-55 months. Using the SMP records as the "gold standard", phone call recall accuracy was assessed for each interview. Data for 94 participants were analyzed. The number of calls made was underestimated considerably and the duration of calls was overestimated slightly in all interviews. Agreement between self-report and SMP records regarding the number of calls, duration of calls and laterality (i.e., use of the dominant ear while making calls) gradually deteriorated with the increase in the interval following the monitoring period (number of calls: first interview: Pearson's r=0.641, third interview: 0.396; duration of calls: first interview: Pearson's r=0.763, third interview: 0.356; laterality: first interview: weighted-κ=0.677, third interview: 0.448). Thus, recall accuracy for mobile phone calls would be consistently imperfect over a long period, and the results of related epidemiological studies should be interpreted carefully.
authors.affiliation: Department of Public Health, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Kiyohara
authors.affiliation: Electromagnetic Compatibility Laboratory, Applied Electromagnetic Research Institute, National Institute of Information and Communications Technology, Koganei, Tokyo, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Wake
authors.affiliation: Electromagnetic Compatibility Laboratory, Applied Electromagnetic Research Institute, National Institute of Information and Communications Technology, Koganei, Tokyo, Japan.
authors.forename: Soichi
authors.initials: S
authors.lastname: Watanabe
authors.affiliation: Division of Advanced Electrical and Electronics Engineering, Tokyo University of Agriculture and Technology, Koganei-shi, Tokyo Japan.
authors.forename: Takuji
authors.initials: T
authors.lastname: Arima
authors.affiliation: Department of Public Health, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan.
authors.forename: Yasuto
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Department of Public Health, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Kojimahara
authors.affiliation: Department of Electrical Engineering, Graduate School of Engineering, Tokyo Metropolitan University, Hachioji, Tokyo, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Taki
authors.affiliation: Barcelona Institute for Global Health (ISGlobal), Barcelona, Spain.|Universitat Pompeu Fabra (UPF), Barcelona, Spain.|CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Cardis
authors.affiliation: Department of Public Health, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan.
authors.forename: Naohito
authors.initials: N
authors.lastname: Yamaguchi
mesh_terms: D000293:Adolescent; D000328:Adult; D040421:Cell Phone / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007407:Interviews as Topic; D007564:Japan; D008297:Male; D011939:Mental Recall; D015203:Reproducibility of Results; D057566:Self Report; D012984:Software; D013334:Students; D055815:Young Adult