The Bradford Factor: What It Measures and How to Use It Fairly

The Bradford factor is a score used by some employers to measure short-term absence. It gives more weight to frequent short absences than to one long absence, because frequent unplanned absences are usually harder to cover: rotas have to be changed at short notice and work is left half done.

Its origin is often linked to research at Bradford University in the 1980s, but this is disputed and hard to confirm. What matters is how it works and how it is used.

How it is calculated

Where S is the number of separate spells of absence and D is the total number of days absent, usually over the last 52 weeks.

Because the number of spells is squared, the same number of days scores very differently depending on how it is split:

Calculate a score

Using it fairly

A score is a prompt to have a conversation, not a reason to act on its own. Points to bear in mind:

• Find out the reason first. Frequent short absences can be caused by an underlying health condition, caring responsibilities or problems at work.
• Disability. Absence related to a disability may need to be treated differently, and employers have a duty to make reasonable adjustments for disabled workers. Counting it in a score that triggers warnings can lead to a discrimination claim.
• Pregnancy. Pregnancy-related absence should not be counted against an employee.
• Be consistent and open. Write down how absence is measured and what happens at each stage, and tell staff.
• Hold return-to-work conversations after each absence. They are often more useful than any score.

Trigger points, the scores at which an employer acts, are set by each employer. There is no official scale. If you use one, apply it with discretion and take advice before formal action. Acas publishes free guidance on managing absence.

The cost of absence

Short-notice absence is often covered by overtime or agency staff. The overtime cost calculator shows what that costs, and the true cost of an employee shows what each working hour is worth.