Table 1.

Variables and indicators.

Socio-demographic data:	Sex, age
Job data:	Sector of activity, type of job, job tenure.
ICT usage in the work activity:	Average daily usage time (hours) of the following types of technologies for work-related activities: desktop, laptop, tablet, and smartphone. Average number of daily pauses in ICT usage (informed by subjects) Average duration of pauses in ICT usage (informed by subjects) Place of usage of ICT devices (Only fixed posts at work; home office; other spaces at home, public places; other spaces)
Preventive measures taken	Technical measures (TM): Check-list (Yes/No) about the availability of: Furniture that allows adopting an adequate posture to perform the task (TM1). Appropriate devices or equipment for the task being performed (TM2). Lecterns, footrests or other elements that contribute to improve posture in front of the computer (TM3). Accessory element(s) (lecterns, supports for tablets, ...) that allow adopting an adequate posture when using smartphones and tablets (TM4).
	Training measures: (TRM): check-list (Yes/No) about the availability in the company of: Training/general information about Occupational Hazard Prevention (TRM1) Computer-related training (TRM2) Training related to the use of other devices (TRM3)
Indicators of occupational health	Visual discomfort: rating scale from 1 (lowest intensity) to 10 (highest intensity) of seven descriptives to collect a subjective rating of visual discomfort after device use (Laubli, Hunting, & Grandjean, 1981; Saito et al., 1994): (a) “My eyes feel tired (visual fatigue)”; (b) “Eyes dry, irritated or burning”; (c) “Eye pain”; (d) “Hard to focus”; (e) “Double vision on screen”; (f) “Flicker vision”; and (g) “Headache”.
	Musculo skeletal disorders (MSDs): Nordic Musculoskeletal Questionnaire (NMQ), (Baron, Hales & Hurrell, 1996). Check-list of 9 items referring to pain or discomfort perceived by workers in different body parts suffered for seven days following the use of ICTs. Response scale ranging from 1 (no pain or discomfort) to 10 (maximum intensity of pain or discomfort).
Performance of physical activity out of the work setting:	Item that shows the extent to which workers practice hobbies or intensive sports activities, play musical instruments or practice activities with instruments that produce vibrations (lawnmower, motor saw, DIY tools, etc.) in their free time. Scale from 0 to 10 points.