Supporting Employees During Long-Term Illness

Most UK employers are confident they handle long-term sickness well. Aviva’s 2025 research found 82% agree they play an important role in getting people back after ill health, and 74% think their organisation is good at doing so. At the same time, economic inactivity due to long-term sickness has reached 2.8 million people, and by 2040 one in five adults in England is projected to live with major illness.

The gap between confidence and outcomes is not about intent. It is about the model of illness that current systems are built on. Most HR frameworks assume a one‑off episode, a clear diagnosis and a steady, linear return from “off sick” to “back at work”. Fluctuating long-term conditions – particularly mental health, now the leading cause of long-term absence – do not behave like that.

This distinction matters.

Take a typical scenario. A high-performing employee develops a fluctuating long-term condition (FLTC). Symptoms vary week to week; energy and cognition are unpredictable. HR policy offers a clear route into sickness absence, occupational health and a staged return. The employee is keen to stay engaged but cannot reliably predict what next Tuesday will look like.

The line manager is caught between a rigid framework and a messy reality. In NHS England research, managers supporting staff with FLTCs described a misalignment between clinical practice, HR procedures and the overarching policy framework, which was often perceived as too rigid for fluctuating conditions. Many felt individually responsible for navigating the system and “ill-equipped” to do so.

The problem is rarely a lack of support in theory. Over half of employees report access to occupational health, rising to 69% in large organisations. Many employers now layer on wellbeing offers – digital GP, lifestyle support, meditation apps. Yet support still tends to focus on getting people back into work quickly rather than helping them stay in work sustainably with ongoing adjustments and day‑to‑day behaviour change support.

For fluctuating conditions, that focus can backfire. If the only defined pathway is from full absence to full return, with a brief period of phased hours, any relapse looks like failure – of the employee or the process. Aviva warns that without a clear, transparent strategy there is a real risk of unnecessary extensions of absence. In effect, systems built for linear recovery push people out when their health does not conform.

Managers then face a second pressure: team perceptions of fairness. NHS clinical managers reported handling comments such as “why are they special?” or “why are they allowed off sick so often?” when a colleague’s pattern of absence looked different. Where policies are rigid but practice has to be flexible, decisions become highly discretionary and hard to explain. Discretion is not inherently bad; unmanaged discretion is.

Across organisations, this creates extensive variation in how people with FLTCs are managed. Some employees access creative, person-centred solutions through cross-departmental collaboration. Others experience repeated assessments, contested absence and a revolving door between sick leave and performance management. The same diagnosis can produce very different outcomes depending on whether a manager happens to know where to look for advice.

The misconception is that having a documented return-to-work process and access to occupational health equals being “good” at long-term sickness. The emerging evidence suggests something tougher: unless HR explicitly designs for fluctuation, existing systems will default to linear recovery – and quietly fail a growing proportion of the workforce.

Redesigning those systems does not mean abandoning structure or asking managers to improvise their way through every complex case. The task is more precise: decide what must be standardised to protect equity and reduce risk, and where flexibility should be deliberately built in.

Start with the foundations. Government research shows only 51% of employees overall have access to occupational health, and just 3 in 10 can access vocational rehabilitation, even though 9 in 10 return to work when they do. For organisations with 100+ employees, 53% offer occupational health and 26% vocational rehabilitation; among micro‑SMEs the figures fall to 5% and 5%. That gap matters to HR leaders in large employers too, because supply chains and partner organisations are often populated by those micro‑SMEs.

At a minimum, HR can standardise:

• Clear criteria and timelines for referral to occupational health and vocational rehabilitation, including for mental health conditions that may not present with a single acute episode.
  
• A default expectation that adjustments are ongoing and revisited regularly, not a one‑off concession. Government data shows 65% of employees with adjustments found the process easy; the opportunity is to make that level of clarity universal.
  
• Board‑level visibility of long-term illness trends through behavioural analytics and data‑driven insights, not just absence counts. Platforms that translate engagement, resilience and mental fitness into pounds‑and‑pence ROI allow wellbeing to sit credibly alongside other workforce metrics in board packs. New‑generation digital EAPs such as Leafyard exemplify this shift from usage statistics to meaningful outcome data.
  

At the same time, HR needs to loosen the right things. NHS research highlighted examples of effective, person‑centred support where HR, occupational health and clinical managers worked collaboratively and adapted central policies locally. These were not heroic exceptions; they were instances where flexibility was intentional and supported.

Practical design moves include:

• Reframing guidance from “return to full duties as quickly as possible” to “identify the sustainable pattern of work that protects health and contribution”, explicitly acknowledging fluctuation.
  
• Building mental fitness into your offer, not only crisis care. Behavioural‑science‑based tools, such as multi‑month digital journeys that combine guided video coaching and structured journalling, help employees build habits for managing stress, sleep and energy before issues escalate into long-term absence. This is prevention, not just rehabilitation, and is the model that platforms like Leafyard are built around.
  
• Giving managers access to microlearning – short, evidence‑based modules they can complete in under 20 minutes – so they are not relying on informal internet searches when a complex case appears.
  

Support also needs to be available when the pattern of work is unconventional. Employees with FLTCs often work irregular hours, from home, or on adjusted shifts. A 24/7 support system – combining intelligent triage to route people quickly to the right level of help, and same‑day access to accredited counsellors by phone or chat – fits the reality of fluctuating symptoms far better than 9‑5 helplines or waiting‑list dependent services. Leafyard’s always‑on, digital‑first model is one example of how this kind of confidential, round‑the‑clock access can be delivered at scale.

Done well, this is not only about the individual. It is about team climate. Managers in the NHS study described anxiety about being seen to treat one person “too leniently”. HR can reduce that burden by providing scripts and manager toolkits that separate equity from sameness: explaining that fluctuating conditions may justify different patterns of presence or performance metrics, and that fairness lies in transparent rationale, not identical treatment.

Mental health is a crucial test case. CIPD highlights mental ill health as the leading cause of long-term absence, and PwC reports that 38% of businesses have seen an increase in long-term sick leave due to mental health. Yet much support still assumes a crisis‑and‑cure model: a short burst of counselling, perhaps a mindfulness app, then a return to “normal”. A mental fitness framing – where employees train coping skills in the same way they would train physical strength – better fits the chronic, relapsing nature of many conditions and underpins the approach taken by Leafyard’s mental fitness platform.

What is working already? There are encouraging signals. Where employees do secure adjustments, most report the process as straightforward. Larger organisations increasingly offer wellbeing benefits, private healthcare and digital GP services that can shorten delays to treatment. And in NHS Trusts, examples of flexible, cross‑departmental approaches have shown that targeted, adaptive interventions can enhance retention and workforce resilience. The raw materials for better systems exist.

The challenge – and opportunity – for HR leaders is to move from isolated good practice to designed capability. That starts close to home. Take one recent long-term absence case and map it against three questions:

• Where did rigid policy or standard performance frameworks clash with the employee’s fluctuating reality?
  
• Where did managerial discretion fill gaps – and was that discretion supported, or left to individual judgement?
  
• Where was there no clear route to occupational health, vocational rehabilitation or preventative mental fitness support?
  

Use the answers to identify two concrete design changes: perhaps tightening your referral pathways, rewriting manager guidance on adjustments for fluctuating conditions, or integrating behavioural‑science‑based mental fitness tools into your core offer.

When long-term illness is treated as a non‑linear journey, supported by intelligent systems instead of ad‑hoc exceptions, fairness becomes easier to explain, managers are less exposed, and more people can stay in work for longer. The belief that “we’re already good at this” is comfortable. The organisations that challenge it now will be better prepared for a future where fluctuating health is the norm, not the exception.