Occupational safety and health indicators

What are occupational safety and health indicators?

An indicator is a variable defined in such a way that it can be measured repeatedly and compared over time or between units. In occupational safety and health, indicators serve three purposes: to describe the situation (how many accidents, how many people exposed, how many pending measures), to evaluate the effectiveness of current actions (whether the measures reduce exposure and harm), and to make data-driven decisions rather than relying on impressions. They are part of the verification phase of any management system and are the raw material for management review.

Spanish regulations do not mandate a set of performance indicators. What they do require is the reporting of workplace accidents, the investigation of health-related injuries, the periodic monitoring of working conditions and employee activity, and the availability of documentation that allows the labor authority to access this data. Official accident statistics are compiled from these reports and use standardized indices, but the selection of internal indicators is a management decision for each organization.

The ILO’s 2001 ILO-OSH guidelines dedicate a section to monitoring and measuring results, recommending a combination of proactive monitoring, which verifies compliance with measures before harm occurs, and reactive monitoring, which records and investigates harm that has already occurred. This distinction is what is now expressed as proactive and reactive indicators.

Reactive indicators and proactive indicators

Both families are necessary and answer different questions.

• Reactive (outcome) indicators measure what has already occurred: number of accidents with and without lost work time, lost workdays, reported occupational illnesses, recorded incidents, and days of incapacity. The classic indices of incidence, frequency, severity, and average duration are reactive indicators standardized by workforce size or hours worked.
• Proactive indicators (activity or process indicators). They measure what the organization does to prevent: percentage of planned measures executed on time, updated assessments, inspections and observations carried out, training hours per person, incidents reported and investigated, hygiene measurements carried out, committee meetings held.
• Exposure and condition indicators. Located between both: number of people exposed above an action value, positions with unacceptable risk pending, equipment without review, contracts without accredited coordination.

A balanced system combines a few indicators of each type. A dashboard composed solely of accident rates is too late, because it measures failure after it has already occurred and is insensitive in small organizations, where a single accident can drastically alter the rate. A dashboard composed solely of activity may show a great deal of preventative work without verifying that it reduces damage. The relationship between these indicators is what informs the effectiveness of the system.

How they are defined and calculated

A poorly defined indicator produces figures that do not mean the same thing in two different centers or time periods. Each indicator needs a data sheet with its definition, formula, data source, frequency, and responsible party.

1. Define the objective: what decision the indicator should support and who will use it.
2. Establish a numerator and denominator. In accident statistics, official indices use hours worked or the average number of people exposed as the denominator; mixing contracted staff with effective staff or excluding contractors and temporary workers without stating so invalidates the comparison.
3. Establish inclusion criteria: what counts as an accident, incident, or action taken, and from what date.
4. Decide the frequency of calculation and review, distinguishing between operational monitoring (monthly) and system review (annual).
5. Ensure data quality: single source, real-time recording, validation by a responsible person, and traceability of changes.
6. Set benchmarks: your own historical data, official industry statistics and, where available, annual targets approved by management.

The official Spanish indices are calculated according to the definitions in the Statistics on Occupational Accidents of the Ministry of Labor and Social Economy, and INSST Technical Note 1, updated by Technical Note 1211, details their calculation within the company. Using the same formulas allows for comparison with the sector.

Organizational application: who uses them and how

The indicators have different target audiences and must be presented differently to each one:

• Management. Few indicators, compared to objectives and the sector, in the periodic review of the system; should allow for the decision of resources and priorities.
• Middle management. Indicators for your area on a monthly or weekly basis: pending measures, inspections, reported incidents, training.
• Prevention service. Comprehensive set, broken down by center, position and type of risk, to guide assessment and planning.
• Safety and health committee and representatives. Information on accident rates, health damages and preventive activity, which Law 31/1995 recognizes their right to know.
• Working people. Simple and contextualized indicators, avoiding presenting figures that stigmatize a team.

Digital management systems facilitate automatic calculation and traceability, but they do not replace the definition of the indicator or the discipline of recording data. Data entered late or incompletely produces an incorrect indicator regardless of the tool used.

Limits and common mistakes

Indicators are a simplification and can be misleading if used without criteria:

1. Managing only the accident rate and rewarding its decrease may discourage the reporting of accidents and incidents.
2. Compare indices between centers or companies with different denominators, or between periods with uncorrected staff changes.
3. Multiply the indicators until nobody reads them; a useful chart usually has between five and fifteen.
4. Confusing activity with effectiveness: many hours of training do not prove that risks have been reduced.
5. Presenting numerical targets as legal obligations; the regulations require prevention, not reaching a specific figure.
6. Not reviewing the indicators when the activity, organization, or main risks change.

The set of indicators should be reviewed at least once a year, in conjunction with the management system review, and whenever a serious accident or major change shows that the figures do not reflect the actual situation.

Regulatory framework in Spain and technical references

• Law 31/1995, articles 16, 23, 36 and 39. Obligation to investigate damage to health and control the effectiveness of the measures, preventive documentation and information rights of the worker safety representatives and the safety and health committee on damage and preventive activity.
• Royal Decree 39/1997, articles 6 and 9. Review of the assessment based on periodic controls and damages caused, and monitoring of preventive planning.
• NTP 1211: Accident statistics in the company (INSST, 2024) . Updates NTP 1 and defines the calculation of the incidence, frequency, severity and average duration rates in the company.
• ILO, Code of Practice on the Recording and Notification of Work-Related Accidents and Occupational Diseases (1996) . International criteria for the recording, notification and statistics of work-related injuries.

The ILO-OSH 2001 guidelines address active and reactive performance monitoring, and ISO 45001 includes requirements for monitoring, measuring, and evaluating performance for organizations that voluntarily adopt it. ISO 45004 offers non-certifiable guidelines for this evaluation. In Colombia, the management system requires structure, process, and outcome indicators with its own rules established by Decree 1072 of 2015, which differ from those in Spain.