Sickness is dealt with under the sickness absence policy. Why would anyone discipline staff for being sick, whether it's short term or long term?

If absences are disability-related then reasonable adjustments must be made. I usually do this following an OH referral (I say usually since my current provider is just awful...)

You can have my current organisation's policy (which I shall shortly be reviewing ) and I think I have an old one from a previous organisation if you ping me a message or an email.

Hi Jackie

It isn't appropriate or fair to issue someone with a warning for something which is beyond their control and which they cannot improve, which is therefore a capability issue, so this comes down to whether you have good reason to believe the employee is malingering or they that they genuinely have a lot of sickness absence.

If someone is off a lot, even if the absences look trivial and unrelated, I would still get an OH opinion as I would want to know if there was a possibility of an underlying cause. In my experience, there generally isn't (horses not zebras) but I did have an employee who was diagnosed with lupus, whereupon her history of absences for all sorts of reasons including putting her back out, pains in various joints and doctor's appointments to get a stubborn rash looked at, suddenly all made sense.

If the absences are genuine but frequent, you then need to take a view on whether the organisation can support that level of absence.

There is a really useful discussion of the difference between capability and conduct here: https://www.cipd.co.uk/Community/discussion-forum/hr_strategy_and_function/f/general/59203/conduct-and-capability-compare-and-contrast/307768#307768 . Capability is considered in a broader sense that illness and covers things which are susceptible to improvement by e.g. providing training, but I think you'll still find it very relevant to you questions.

Hi Jackie
Peter C published a fantastic post some years ago on capability vs conduct. suggest you look for it - it may even be in the wiki.

Basically Capability="Can't" - I don't have the skills, abilities, authorisations to do what is required
Conduct ="Won't" - I am wilfully behaving in this way even if I have the skills and abikities to do better

Elizabeth beat me to it and posted avlink to Peter Cunningham's fantastic post on this subject

In reply to Ray:

:)