How do you measure H&S performance?

Bridget Leathley explains how measuring safety performance before harm occurs can lead to much more effective health and safety management.

Traditionally, the key indicator of health and safety performance is the number of people who had an accident that resulted in time-off work or a hospital visit, permanent disability or worse. Some companies attempt to measure some of the smaller accidents, for example by asking first aiders to make a report each time they deliver first aid, even if it’s a minor cut treatable with a sticking plaster.

Some hazards, such as noise, vibration and lead, have a requirement for health surveillance. Night shift workers must be offered a health assessment before becoming a night worker, and at regular intervals. As well as providing individuals with advice on protecting themselves from the effects of the relevant hazards, data from health surveillance and assessments provide an indicator of how well the organisation is managing the hazard. If the hearing of one group of workers deteriorates quickly, it’s a good reason to review sound levels where they work.

Working with HR departments, safety teams might be able to get records of the reasons people take time off work for ill-health. But even then, whether the back pain is related to manual handling at work or digging the garden at the weekend, or whether the anxiety is work-related or from a domestic source, is often not reported.

Our first take away therefore is that we need to be better at measuring performance on managing our workers’ health, as well as their safety. If you are going to ask people for information about the reasons for their sickness absence, they need to know it will be kept secure, and that you will use the data to make their workplace better. You don’t need to ask detailed and intrusive questions about people’s home life – the sickness absence is either work-related or ‘other’. If it is work-related, you might need to follow-up with the individual to find out more about the cause.

Counting accidents, even small ones, looking at health surveillance data and adding up the number of days of sickness absence that are due to work-related illnesses are lagging measures. That is, they measure what has already happened. This is a useful starting place, for example to identify that more must be done to reduce vibration exposure, that staff in one department appear to suffer more stress than the average, or that workers in the warehouse have taken more time off with musculoskeletal (MSK) problems since the delivery schedules changed.

But what if we could measure safety performance before the accident or sickness absence, and before the symptom is detected through health surveillance? It would be like having a time machine – we could prevent the harm instead of measuring it.

The term ‘leading measures’ is used to describe ways in which organisations measure their safety performance before harm occurs. This means assessing the effectiveness of the controls in the risk assessment. Regulation 5 of the Management of Health and Safety at Work Regulations makes it clear that it’s not enough to list some controls in a risk assessment document. You must also have appropriate arrangements “for the effective planning, organisation, control, monitoring and review” of those controls.  “Review” implies using the results from monitoring to modify controls and hence to improve safety.

We’ll work through three examples to illustrate how leading indicators can measure the performance of your controls and suggest improved controls – before an accident occurs.

Noise

A manufacturing company has audiometry tests as part of regular health surveillance. These will provide an early indication if noise controls are not working. But while it might prevent further harm, the damage already caused will be irreversible. For example, while someone can still hear a conversation, they might already have lost the ability to hear quieter noises at certain frequencies.

The company selected the quietest machinery they could afford at the time which would do the job. Noise levels monitored on installation indicated that hearing protection would not be needed. Is an annual service enough to make sure the machinery doesn’t become noisier over time?

A leading measure of performance would be additional assessments of the noise levels. Previously this would have involved acoustic engineers visiting with specialised equipment. Apps are now available on mobile phones to assess noise, but while these show some potential, research suggests they are not yet completely reliable. Instead, the company installs a commercial system which can provide a constant measure of noise levels in key places suggested by an acoustic specialist. The health and safety manager and the maintenance supervisor are alerted if a peak or average noise exceeds a set threshold. In this way, the company can assess whether annual maintenance has been sufficient to manage noise levels or whether additional maintenance is needed. Even where noise levels are below action levels set by legislation, the data will help the manufacturer to identify the priority areas for further noise reduction.

Slips and trips

Slips and trips are the most common cause of non-fatal accidents in the workplace, accounting for nearly a third of all cases.

The facilities management (FM) team for an office building collate a lagging measure of safety performance by asking all building users to report slips and trips.

To prevent slips and trips the FM team carry out housekeeping inspections, and ask staff to report puddles, damaged carpets and other hazards which could lead to a slip or trip. Counting the slip and trip hazards identified during inspections, and the number reported by staff, would be one leading measure of safety performance. However, staff reporting can be unreliable, as an increase in reports could be a positive sign of increased awareness.

The FM team have been told to prioritise the hazards which seem the most dangerous. For example, a spill in the entrance lobby would be mopped up before one in a less frequently used storage area. Tracking how long it takes to fix each problem could be a useful leading performance measure.

Good data on the location of reported issues will enable the FM team to see if repeated problems need further investigation. Why are puddles frequently reported in the kitchenette on the 3^rd floor, but only occasionally in other kitchens? Is the fridge or the coffee machine faulty? Is there a leak under the sink? The FM team use the proactive performance data to identify where additional maintenance is needed.

Workplace vehicle management

Over the five-year period to March 2025, an average of 21 people died and 1,300 were injured each year in the UK after being hit by a moving vehicle at work.

A waste recycling site has had no reports of pedestrians hit by vehicles. The safety manager wants to know if this is luck, or the effectiveness of controls such as site layout and segregated walkways.

A leading measure could be for the safety manager to observe pedestrian compliance. But every time the safety manager stands watching, not surprisingly, people use the correct routes. Even watching CCTV playback from the CCTV at speed, it’s going to be time consuming.

After consulting worker representatives, a computer vision (CV) system is installed. CV can be configured to identify automatically every time someone goes over, under or through the barriers, across the weighbridge, or directly in the path of vehicles. Clips are saved for the safety manager to review, with faces blurred, so it is clear that the system is being used to provide a leading measure of safety performance, not to ‘catch out’ individual workers.

The system shows that there is a peak in the number of people walking across the vehicle route at 10am every day. Workers explain that they have to rush to the portacabin to avoid the queue for the drink machine. Those who take the short cut get their drinks first, while those who take the longer, correct route sometimes run out of time to drink their coffee!

Workers suggest splitting breaktimes, and management offer to buy a second drink machine. The data from the computer vision system shows an immediate drop in the number of people walking across vehicle routes.

Generally

While a lagging measure counts the number of times harm occurs, leading measures assess the effectiveness of the controls.

In each case, you need to know what the hazard controls are. If these are not well defined in your risk assessments, it will be impossible to monitor them. If you are going to base a leading measure of performance on ‘housekeeping’ or ‘training’ you will need to be more specific about what those controls mean.

Measure the noise, not the deafness; inspect for puddles and damaged floors rather than count the slips and trips; check that pedestrians and vehicles stay apart, rather than wait for someone to be hit. Once you have your leading measures, use these to improve safety.

Measuring performance is one of the key topics covered on the IOSH Managing Safely course that RoSPA offers via e-learning, virtual classroom or in-company.

Aimed at those in a managerial or supervisory role in any industry who wants to gain a robust foundation in the essentials of health and safety, the course equips participants with the knowledge, confidence, and motivation to apply safety principles effectively in the workplace and plays a key role in fostering a strong, positive health and safety culture throughout an organisation. 

Find out more about IOSH Managing Safely course here

Our two-day Auditing and Reviewing Health and Safety Management Systems course is designed to empower you to conduct effective health and safety audits. This training equips participants with the necessary skills to assess current policies, procedures and safety management systems and is available via virtual classroom or in-company.

Find out more about Auditing and Reviewing Health and Safety Management Systems here