title: A cross-sectional study of the association between mobile phone use and symptoms of ill health.
abstract: OBJECTIVE
  This study analyzed the associations between mobile phone call frequency and duration with non-specific symptoms.
  
  
  METHODS
  This study was conducted with a population group including 532 non-patient adults established by the Korean Genome and Epidemiology Study. The pattern of phone call using a mobile phone was investigated through face-to-face interview. Structured methods applied to quantitatively assess health effects are Headache Impact Test-6 (HIT-6), Psychosocial Well-being Index-Short Form, Beck Depression Inventory, Korean-Instrumental Activities of Daily Living, Perceived Stress Scale (PSS), Pittsburgh Sleep Quality Index, and 12-item Short Form Health Survey where a higher score represents a higher greater health effect.
  
  
  RESULTS
  The average daily phone call frequency showed a significant correlation with the PSS score in female subjects. Increases in the average duration of one phone call were significantly correlated with increases in the severity of headaches in both sexes. The mean (standard deviation) HIT-6 score in the subgroup of subjects whose average duration of one phone call was five minutes or longer was 45.98 (8.15), as compared with 42.48 (7.20) in those whose average duration of one phone call was <5 minutes. The severity of headaches was divided into three levels according to the HIT-6 score (little or no impact/moderate impact/substantial or severe impact), and a logistic regression analysis was performed to investigate the association between an increased phone call duration and the headache severity. When the average duration of one phone call was five minutes or longer, the odds ratio (ORs) and the 95% confidence intervals (CIs) for the moderate impact group were 2.22 and 1.18 to 4.19, respectively. The OR and 95% CI for the substantial or severe impact group were 4.44 and 2.11 to 8.90, respectively.
  
  
  CONCLUSIONS
  Mobile phone call duration was not significantly associated with stress, sleep, cognitive function, or depression, but was associated with the severity of headaches.
authors: Institute for Life and Environment Technology, Smartive Corporation, Seoul, Korea.
authors: Yong Min
authors: 0000-0002-8999-8916
authors: YM
authors: Cho
authors: Institute for Occupational and Environmental Health, Korea University, Seoul, Korea.
authors: Hee Jin
authors: 0000-0001-5295-0137
authors: HJ
authors: Lim
authors: Institute for Occupational and Environmental Health, Korea University, Seoul, Korea.
authors: Hoon
authors: 0000-0001-8549-8001
authors: H
authors: Jang
authors: Institute for Occupational and Environmental Health, Korea University, Seoul, Korea.
authors: Kyunghee
authors: 0000-0002-5333-9716
authors: K
authors: Kim
authors: Institute for Occupational and Environmental Health, Korea University, Seoul, Korea.
authors: Jae Wook
authors: 0000-0002-1996-7524
authors: JW
authors: Choi
authors: Institute of Human Genome Study, Korea University Ansan Hospital, Ansan, Korea.
authors: Chol
authors: 0000-0002-2928-8576
authors: C
authors: Shin
authors: Institute of Human Genome Study, Korea University Ansan Hospital, Ansan, Korea.
authors: Seung Ku
authors: 0000-0001-5120-5557
authors: SK
authors: Lee
authors: EM Environment Research Team, Electronics and Telecommunications Research Institute, Daejeon, Korea.
authors: Jong Hwa
authors: 0000-0002-2132-7403
authors: JH
authors: Kwon
authors: Division of Information and Communication Engineering, Chungbuk National University, Chungju, Korea.
authors: Nam
authors: 0000-0001-8109-2055
authors: N
authors: Kim
keywords: Headache Impact Test-6; Headaches; Mobile phones; Non-specific symptoms