Health symptoms were assessed by the Headache Impact Test-6 (HIT-6), the Psychosocial Well-being Index-Short Form (PWI-SF), the Beck Depression Inventory (BDI), the Korean-Instrumental Activities of Daily Living (K-IADL), the Perceived Stress Scale (PSS), the Pittsburgh Sleep Quality Index (PSQI) and the 12-item Short Form Health Survey (SF-12).
The results of the cross-sectional study of the same study population are published in Cho et al. (2016).
|Group 1||average call duration: < 5 min at baseline and follow-up|
|Group 2||average call duration: ≥ 5 min at baseline and < 5 min at follow-up|
|Group 3||average call duration: < 5 min at baseline and ≥ 5 min at follow-up|
|Group 4||average call duration: ≥ 5 min at baseline and follow-up|
The average duration per mobile phone call decreased significantly between baseline and follow-up (median: 1.5 min, 1.3 min respectively) .
A significant correlation was observed between the reduction in the average call duration and a decrease in headache among women only. Severity of headaches in the follow-up survey significantly decreased compared to those in the baseline survey (groups 1-3). Mobile phone use was not significantly associated with stress, sleep, cognitive function, or depression.
The authors conclude that an increased mobile phone call duration is a greater risk factor for increases in headache than any other type of adverse health effect, and that this effect could be chronic.