How can we better use Twitter to find a person who got lost due to dementia?

Flow chart of data extraction from Twitter. Boxes with different colours represent different types of data: green for Twitter users; blue for tweets and retweets on Twitter; and red for people who got lost with dementia. 1 Natural language processing (NLP) was used to identify name, age and location of the person who got lost from the tweet contents. 2 Six people were excluded because one person got lost before the study period, the names of two people could not be identified, and three people were found before the first original tweet. 3 Twitter users only included tweet-writers and retweeters. Number of followers were extracted from the individual user