Mikkelsen Sigurd, Vilstrup Imogen, Lassen Christina Funch, Kryger Ann Isabel, Thomsen Jane Frølund, Andersen Johan Hviid
Department of Occupational Medicine, Copenhagen University Hospital, Glostrup, Denmark.
Occup Environ Med. 2007 Aug;64(8):541-7. doi: 10.1136/oem.2005.026351. Epub 2007 Mar 26.
To examine the validity and potential biases in self-reports of computer, mouse and keyboard usage times, compared with objective recordings.
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.
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.
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.
与客观记录相比，检验计算机、鼠标和键盘使用时间自我报告的有效性及潜在偏差。
对1211名研究对象进行问卷调查，询问他们在过去四个工作周内使用计算机、鼠标和键盘的平均时间。在同一时期，通过软件程序客观记录这些活动。该研究是2000 - 2001年对丹麦计算机工作者肌肉骨骼疾病转归进行的为期一年随访研究的一部分。
计算机、鼠标和键盘使用时间的自我报告与客观测量的活动呈正相关，但有效性较低。自我报告仅解释了客观测量活动方差的四分之一到三分之一，对于一项测量指标（键盘使用时间）甚至更低。自我报告高估了使用时间。在低水平时高估幅度较大，且随着客观测量活动水平的增加而下降。鼠标使用时间比例是个例外，几乎呈1:1关系。客观测量活动的变异性、手臂疼痛、性别和年龄以一种系统的方式影响自我报告，但影响较小，且有时方向不同。
计算机活动的自我报告持续时间与客观测量结果呈正相关，但相当不准确。使用自我报告来确定计算机工作时间与肌肉骨骼疼痛之间关系的研究可能存在偏差，并导致风险估计错误地增加或减少。
