Complex does not have to mean complicated
Some students make the mistake of thinking that they need to turn each individual case note into a sentence. They then combine a number of sentences into paragraphs and paragraphs into a letter. This is not a good strategy.
To score well in OET, you need to demonstrate to the assessor that you can make decisions about the case notes. Of course, you first need to decide which notes are relevant to include and which ones to omit. After this, you need to decide which case notes should be combined. Too many short simple sentences create a letter that does not read very smoothly and cohesively as in these examples:
The patient is a lawyer. He is a heavy smoker. His diet is poor. He often works on weekends. He likes to play sport.
What would be better is to combine some of these to make more complex sentences:
He is a lawyer and often works on weekends. Despite enjoying playing sport, he smokes and has a poor diet.
Complex doesn’t have to mean long and complicated. Instead, complex sentences can easily combine ideas to clearly present the information to the reader in an efficient manner.