OBJECTIVE: To examine the validity and potential biases in self-reports of computer, mouse and keyboard usage times, compared with objective recordings. METHODS: A study population of 1211 people was asked in a questionnaire to estimate the average time they had worked with computer, mouse and keyboard during the past four working weeks. During the same period, a software program recorded these activities objectively. The study was part of a one-year follow-up study from 2000-1 of musculoskeletal outcomes among Danish computer workers. RESULTS: Self-reports on computer, mouse and keyboard usage times were positively associated with objectively measured activity, but the validity was low. Self-reports explained only between a quarter and a third of the variance of objectively measured activity, and were even lower for one measure (keyboard time). Self-reports overestimated usage times. Overestimation was large at low levels and declined with increasing levels of objectively measured activity. Mouse usage time proportion was an exception with a near 1:1 relation. Variability in objectively measured activity, arm pain, gender and age influenced self-reports in a systematic way, but the effects were modest and sometimes in different directions. CONCLUSION: Self-reported durations of computer activities are positively associated with objective measures but they are quite inaccurate. Studies using self-reports to establish relations between computer work times and musculoskeletal pain could be biased and lead to falsely increased or decreased risk estimates.
OBJECTIVE: To examine the validity and potential biases in self-reports of computer, mouse and keyboard usage times, compared with objective recordings. METHODS: A study population of 1211 people was asked in a questionnaire to estimate the average time they had worked with computer, mouse and keyboard during the past four working weeks. During the same period, a software program recorded these activities objectively. The study was part of a one-year follow-up study from 2000-1 of musculoskeletal outcomes among Danish computer workers. RESULTS: Self-reports on computer, mouse and keyboard usage times were positively associated with objectively measured activity, but the validity was low. Self-reports explained only between a quarter and a third of the variance of objectively measured activity, and were even lower for one measure (keyboard time). Self-reports overestimated usage times. Overestimation was large at low levels and declined with increasing levels of objectively measured activity. Mouse usage time proportion was an exception with a near 1:1 relation. Variability in objectively measured activity, arm pain, gender and age influenced self-reports in a systematic way, but the effects were modest and sometimes in different directions. CONCLUSION: Self-reported durations of computer activities are positively associated with objective measures but they are quite inaccurate. Studies using self-reports to establish relations between computer work times and musculoskeletal pain could be biased and lead to falsely increased or decreased risk estimates.
Authors: Fredric Gerr; Michele Marcus; Cindy Ensor; David Kleinbaum; Susan Cohen; Alicia Edwards; Eileen Gentry; Daniel J Ortiz; Carolyn Monteilh Journal: Am J Ind Med Date: 2002-04 Impact factor: 2.214
Authors: Michele Marcus; Fredric Gerr; Carolyn Monteilh; Daniel J Ortiz; Eileen Gentry; Susan Cohen; Alicia Edwards; Cindy Ensor; David Kleinbaum Journal: Am J Ind Med Date: 2002-04 Impact factor: 2.214
Authors: Lars Peter Andreas Brandt; Johan Hviid Andersen; Christina Funch Lassen; Ann Kryger; Erik Overgaard; Imogen Vilstrup; Sigurd Mikkelsen Journal: Scand J Work Environ Health Date: 2004-10 Impact factor: 5.024
Authors: Christina Funch Lassen; Sigurd Mikkelsen; Ann Isabel Kryger; Lars P A Brandt; Erik Overgaard; Jane Frølund Thomsen; Imogen Vilstrup; Johan Hviid Andersen Journal: Am J Ind Med Date: 2004-11 Impact factor: 2.214
Authors: Ewa Wigaeus Tornqvist; Mats Hagberg; Maud Hagman; Eva Hansson Risberg; Allan Toomingas Journal: Int Arch Occup Environ Health Date: 2009-02-10 Impact factor: 3.015
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: Philippe Kiss; Marc De Meester; André Kruse; Brigitte Chavée; Lutgart Braeckman Journal: Int Arch Occup Environ Health Date: 2011-05-10 Impact factor: 3.015
Authors: Che-Hsu Joe Chang; Peter W Johnson; Jeffrey N Katz; Ellen A Eisen; Jack T Dennerlein Journal: Eur J Appl Physiol Date: 2008-10-14 Impact factor: 3.078
Authors: Jennifer L Bruno Garza; Paul J Catalano; Jeffrey N Katz; Maaike A Huysmans; Jack T Dennerlein Journal: J Occup Environ Hyg Date: 2012 Impact factor: 2.155
Authors: Douglas A Parry; Brittany I Davidson; Craig J R Sewall; Jacob T Fisher; Hannah Mieczkowski; Daniel S Quintana Journal: Nat Hum Behav Date: 2021-05-17