Duration of total computer use and difference between questionnaire data and information of Workpace recorder for different groups of employees
| Mean hours wp (1) | Mean hours quest (2) | Mean difference (h) (3) | Mean difference (%) (4) | Mean difference (ratio) (5) | |
|---|---|---|---|---|---|
| *Work related musculoskeletal disorders of upper extremities. | |||||
| (1) Mean duration of total computer use in hours according to Workpace recorder. | |||||
| (2) Mean duration of total computer use in hours according to the questionnaire. | |||||
| (3) Mean difference in hours [(2)−(1)]. | |||||
| (4) Mean difference as percentage of total estimated time [(3)/(2) × 100%]. | |||||
| (5) Mean difference as ratio of questionnaire estimation/Workpace information [(2)/(1)]. | |||||
| Total population computer workers (n = 70) | 2.5 | 4.1 | 1.6 | 39 | 1.6 |
| Employees who reported maximum 3 hours of computer use per day according to the questionnaire (n = 16) | 1.7 | 2.1 | 0.4 | 19 | 1.2 |
| Employees who reported >3 hours of computer use per day according to the questionnaire (n = 54) | 2.7 | 4.7 | 2.0 | 43 | 1.7 |
| Employees with WRMSDs* (n = 35) | 2.6 | 4.4 | 1.8 | 41 | 1.7 |
| Employees without WRMSDs* (n = 32) | 2.4 | 3.9 | 1.5 | 38 | 1.6 |