For back pain? More than half of the people at some point in life develop some for back pain. It's scary so if you can afford a scan you get it. Of course there's nothing wrong and the pain goes away by itself in following months, usually after switching chair in which you spend most of your waking hours.

I can't imagine someone in the UK getting scans for lower-back back pain unless there was some clinical need for it.

The advice for most people would tend to be "lose weight, get exercise, check your beds and chairs; and carefully take paracetamol for the pain".