BACKGROUND: Although visual display terminal (VDT) work has become a common task among office workers, surveys which would help to determine the allowable duration of daily VDT use are limited. METHODS: We investigated more than 25,000 workers three times over a 3-year period using a self-administered questionnaire. Three factors, namely mental, physical and sleep-related symptoms, were extracted by factor analysis. Adjusted means of each factor score were compared with the duration of daily VDT use by general linear model. RESULTS: Physical symptoms score became higher with increasing duration of daily VDT use without a threshold effect. Mental and sleep-related symptom scores of the workers using VDT for more 5 hr/day were significantly higher than that of the groups using VDT for >1, 1-3, and 3-5 hr/day. CONCLUSIONS: Duration of daily VDT use was linearly related to the physical symptom score, and was non-linearly related to mental and sleep-related symptom score with a threshold effect of 5 hr/day. Copyright 2002 Wiley-Liss, Inc.
BACKGROUND: Although visual display terminal (VDT) work has become a common task among office workers, surveys which would help to determine the allowable duration of daily VDT use are limited. METHODS: We investigated more than 25,000 workers three times over a 3-year period using a self-administered questionnaire. Three factors, namely mental, physical and sleep-related symptoms, were extracted by factor analysis. Adjusted means of each factor score were compared with the duration of daily VDT use by general linear model. RESULTS: Physical symptoms score became higher with increasing duration of daily VDT use without a threshold effect. Mental and sleep-related symptom scores of the workers using VDT for more 5 hr/day were significantly higher than that of the groups using VDT for >1, 1-3, and 3-5 hr/day. CONCLUSIONS: Duration of daily VDT use was linearly related to the physical symptom score, and was non-linearly related to mental and sleep-related symptom score with a threshold effect of 5 hr/day. Copyright 2002 Wiley-Liss, Inc.
Authors: Sigurd Mikkelsen; Christina Funch Lassen; Imogen Vilstrup; Ann Isabel Kryger; Lars Peter Andreas Brandt; Jane Frølund Thomsen; Mette Gerster; Søren Grimstrup; Johan Hviid Andersen Journal: Int Arch Occup Environ Health Date: 2011-05-24 Impact factor: 3.015
Authors: Sigurd Mikkelsen; Imogen Vilstrup; Christina Funch Lassen; Ann Isabel Kryger; Jane Frølund Thomsen; Johan Hviid Andersen Journal: Occup Environ Med Date: 2007-03-26 Impact factor: 4.402