Q: I haven't heard from the editor though the status says "Decision made." What could be the reason?

Once the decision regarding a paper has been made, it is usually communicated to the author within a few days. Although it is slightly unusual that it has been more than a week and you have not yet received any formal communication from the editor, it can happen on some occasions. Perhaps the editor is extremely busy at this point of time or the journal has to complete some internal processes before sending a formal email to the author. Another possibility is that the editor has sent you an e-mail, but for some reason, it hasn't reached you.

If you do not receive any communication within another week, you could write to the editor inquiring about this.