What is health surveillance?
Health surveillance continuously monitors the relationship between working conditions and health. It may include questionnaires, examinations or specific tests, damage analysis, group studies, and trend reviews. Its objectives are to detect effects early, identify particular sensitivities, verify whether protective measures are effective, and provide information for reviewing assessments and planning.
It has both an individual and a collective dimension. The individual dimension addresses each person exposed and offers health recommendations. The collective dimension analyzes aggregated results to discover patterns by position, agent, or task. Both must be linked to prevention: detecting an effect requires investigating the possible work-related link and evaluating measures, not just repeating assessments.
Differences from medical examinations and health promotion
Medical examinations are one possible technique within surveillance, but not the entirety of it. A generic examination, the same for all staff and unrelated to the assessed risks, does not, on its own, fulfill the preventive purpose. Surveillance must be specific and proportionate to exposure, use appropriate protocols, and cause the least possible inconvenience.
Health promotion encourages healthy habits and environments, but it is complementary. Dietary or exercise campaigns cannot replace the elimination of workplace exposures. Nor should health surveillance be confused with absenteeism control or personnel selection. Its purpose is to protect health, respect rights, and improve working conditions.
When is it done and what criteria are used?
The Prevention Services Regulations stipulate an initial assessment upon joining the workforce or being assigned tasks with new risks, assessments following prolonged absences due to health reasons to detect potential occupational causes and recommend measures, and periodic monitoring. The frequency and tests depend on the risk, the evidence, the specific regulations, and health criteria. Some agencies require monitoring even after exposure has ended.
As a general rule, monitoring is voluntary for the employee. Law 31/1995 provides for exceptions, with prior notification to the workers’ representatives, when it is essential to assess the effects of working conditions, verify whether the state of health may pose a danger to the individual or others, or when a legal provision so establishes with respect to specific risks and particularly hazardous activities. These exceptions are to be interpreted restrictively and proportionately.
Confidentiality and communication of results
Health information is limited to medical personnel and the competent health authorities. The employee must be informed of their results. The company and those with preventative responsibilities receive only the necessary conclusions regarding fitness for the job or the need to introduce or improve measures, without access to diagnoses or clinical data. The results may not be used for discriminatory purposes or to the detriment of the individual.
Systems that store data must separate clinical and preventative management information, apply strict permissions, retain data for applicable periods, and log access. Health data is a particularly protected category. Employee consent does not make any data collection lawful: purpose, legal basis, necessity, proportionality, and security must be analyzed before processing.
How it integrates into prevention
The process begins with an updated risk assessment and a clear list of job positions and exposures. Based on this, healthcare personnel define protocols, target population, frequency, and referral criteria. After individual assessments, results and authorized preventive conclusions are communicated to each person. The collective analysis, anonymized or aggregated as appropriate, is compared with observed incidents, illnesses, and conditions.
If any problems or trends appear, the occupational health and safety service must investigate, review the assessment, and propose corrective measures. Attention to particularly vulnerable individuals is also monitored. Coordination between occupational medicine and the disciplines of safety, hygiene, ergonomics, and psychosocial factors is essential. Monitoring that does not provide feedback to management becomes an isolated activity and loses much of its preventive value.
Practical example
Shoulder discomfort is on the rise in an order preparation area. Previous assessments had identified frequent arm elevation, but no clustering of injuries had been observed. Healthcare staff analyzed collective results without reporting individual diagnoses and detected a concentration at two workstations with high shelving.
The prevention team reviews the task, moves fast-moving items to lower shelves, adds a handling aid, and shortens reach distances. Individual assessments are offered, and the workstation is adapted when necessary. Exposure and collective health indicators are then monitored to verify the change. The company receives conclusions and recommendations, not medical records. This case demonstrates the correct approach: health information drives workplace intervention.
Regulatory framework in Spain
Article 22 of Law 31/1995 regulates employer guarantees, voluntariness and exceptions, proportionality, confidentiality, communication of conclusions, and possible extension after the employment relationship ends. Article 37.3 of Royal Decree 39/1997 specifies the healthcare functions, the evaluation periods, and the occupational health record. Royal Decree 843/2011 establishes basic criteria regarding human and material resources and the organization of healthcare services within occupational health and safety services.
Specific regulations for certain agents or activities may add requirements and retention periods. The Ministry of Health publishes specific health surveillance protocols and sector-specific guidelines; these should be selected according to the actual risks and not applied mechanically. INSST Technical Note 959 summarizes principles and distinguishes between individual and collective objectives, although Technical Notes are technical guidelines and not binding regulations.
