Bradford Factor: how to use it without creating problems

The Bradford Factor is a formula used to quantify the impact of short-term, frequent absences on an organisation. It is named after the University of Bradford, where research into short-term absence patterns was conducted in the 1980s. The formula is: Bradford Score = S² × D, where S is the number of separate absence spells in a rolling period (typically 52 weeks) and D is the total days absent in the same period.

The formula weighs frequency more heavily than duration. An employee who is absent for ten separate one-day periods has a Bradford score of 100 × 10 = 1,000. An employee who has one extended absence of ten days has a score of 1 × 10 = 10. The argument is that frequent short absences — which tend to be unpredictable and disruptive — have a disproportionate operational impact compared to a single longer absence.

Many organisations use trigger points: a Bradford score above a threshold (commonly 150 or 250) triggers a formal review or conversation. Some use a tiered approach — a score of 150 to 250 triggers an informal discussion; above 250 triggers a formal absence management meeting.

The Bradford Factor is a useful tool, but it has real limitations that can create problems if it is applied mechanically.

The most significant risk is its potential interaction with disability. Frequent short absences can be a feature of chronic conditions — rheumatoid arthritis, Crohn's disease, mental health conditions — that amount to a disability under the Equality Act. Triggering formal absence procedures purely on Bradford score, without considering whether the absences are disability-related, can constitute indirect disability discrimination. A reasonable adjustment for a disabled employee may be to exclude absences linked to their disability from the Bradford calculation.

Pregnancy-related absences must be excluded. Absences caused by pregnancy or a pregnancy-related condition must not be counted in any absence management calculation, including Bradford. Including them risks an automatically unfair dismissal claim and a pregnancy discrimination claim.

Mental health and stress absences deserve particular care. An employee whose Bradford score is rising because of work-related stress may be in a situation where absence management pressure escalates rather than addresses the underlying problem.

Best practice is to use the Bradford Factor as a prompt for a conversation, not as a decision-making mechanism. When a trigger point is reached, the right response is a return-to-work interview to understand the pattern — not a formal disciplinary without investigation. See our guide on return to work interviews for how to handle those conversations.

For the full absence management framework, see managing long-term sickness absence fairly.

Mellow calculates Bradford scores automatically and flags trigger thresholds, while also tracking disability-related and pregnancy-related absences separately. [Start a free trial →](https://mellowhr.com/register)