Understanding 分かる in this sentence > **** > According to the police, in this test, in around 1 year, there were 57099 people who were told that they might have a brain disease called dementia. 1892 of these people _knew they had dementia because a doctor had tested them_. I'm having trouble understanding the sentence in bold. The translation is my best guess. My understanding of is a bit shaky. Does this sentence suggest that the 1892 people already knew they had dementia **before** they took the police test, or does it imply that those people went to the doctor **after** the police test and were then confirmed as having dementia? (putting aside the fact that a person diagnosed with dementia might still not _know_ they have dementia).

This is close to (become clear) rather than "know". So means "It became clear that 1892 of these people had dementia because a doctor had tested them."

We can't know why they took police test and when they knew they had dementia just from this sentence.