title: Prevalence of headache among handheld cellular telephone users in Singapore: a community study.
abstract: We carried out a cross-sectional community study in Singapore to determine the prevalence of specific central nervous system (CNS) symptoms among hand-held cellular telephone (HP) users compared to nonusers and to study the association of risk factors and CNS symptoms among HP users. A total of 808 men and women between 12 and 70 years of age, who lived in one community, were selected using one-stage cluster random sampling and responses to a structured questionnaire. The prevalence of HP users was 44.8%. Headache was the most prevalent symptom among HP users compared to non-HP users, with an adjusted prevalence rate ratio of 1.31 [95% confidence interval, 1.00-1.70]. There is a significant increase in the prevalence of headache with increasing duration of usage (in minutes per day). Prevalence of headache was reduced by more than 20% among those who used hand-free equipment for their cellular telephones as compared to those who never use the equipment. The use of HPs is not associated with a significant increase of CNS symptoms other than headache.
authors: Department of Community, Occupational & Family Medicine, National University of Singapore, Singapore, Republic of Singapore. cofcse@nus.edu.sg
authors: S E
authors: SE
authors: Chia
authors: H P
authors: HP
authors: Chia
authors: J S
authors: JS
authors: Tan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002493:Central Nervous System Diseases / Q000209:etiology; D002648:Child; D003430:Cross-Sectional Studies; D004781:Environmental Exposure; D004782:Environmental Health; D005260:Female; D006261:Headache / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D008297:Male; D008872:Microwaves / Q000009:adverse effects*; D008875:Middle Aged; D012307:Risk Factors; D012846:Singapore / Q000453:epidemiology; D013689:Telephone