We have 6 months full pay, 6 months half. You can be referred to HR for review, but I'm not sure if it's done on Bradford or at manager's discretion or what. From what I've seen, they're generally good, and there is flexibility for people with more chronic conditions (home-working, flexible hours and so on.) There is mostly an attitude of "how can we support you getting back to getting working fit?" rather than, "we need you out." Some of it us down to manager's discretion, and some are more reasonable than others, although not the manager who tried to advise a male colleague not to have a vasectomy, as he was advised to have a week off for recovery. Same manager also complains about men taking paternity leave, so... Obviously some people do pull sickies when they shouldn't, and that should be investigated rather than supported, but I think it's generally assumed as a starting point that people do sometimes get ill, and need support, rather than they're just being awkward.
Some people are more prone to illness than others - one colleague had a stroke, and for 3 or 4 years, seemed to succumb to any passing illness going, including glandular fever which left him hospitalised. It's only been the last year or so that his immune system seems to be back up to full strength. It would not have helped him to regain his strength to have ended up on a disciplinary.
They have terminated people in the past. I only know of one directly, and he'd only managed about two days in the office in a year, and wasn't likely to be increasing it soon.
Our department is spread across Europe, and it's interesting seeing how different countries handle illness. Germans seem to get signed off at the drop of a hat, and will be signed off to the end of the week for things I wouldn't even bother the GP with, and only expect a day or two out of the office (colds and dodgy stomachs.) They also get granted extra holiday if someone has been off with something major, and seem to be better at doing staged returns (building back up to full-time over a period, rather than straight back in to FT) - although I have seen more staged returns over here, too in the last few years. Maybe I am just getting to an age where people are more likely to have had a major illness, so I just know more about it.