Most paragraphs start with a topic sentence, then after that comes the supporting evidence. Supporting evidence:
The example of a topic sentence from the previous page was "General Practice doctors are often too busy to see patients in person..."
Now, have a look at the supporting evidence for that topic sentence:
"...Smith (2018) found that 64% of enquiries to doctors' surgeries were referred to the NHS Online website rather than being given an appointment. When patients do go to a surgery, they are usually seen by practice nurses rather than the GP (Brown, 2015)."