Some styles insist that if you have mentioned the author's name in the text, then you should drop the author's name from the citation, e.g. These results were confirmed by Smith (1993).

This can easily be done with EndNote. Click on the citation in your Word document to highlight it. Select the Edit Citation(s) command from the EndNote tools.

You will now see a dialogue box. Check the box labelled Exclude author and then click on the OK button.

With recent versions of EndNote, there is an even quicker way of doing this. Do a right-click on the citation in the text and you will see a context menu. One of the items on that menu is Edit Citation(s). This option has a sub-menu, including the Exclude Author command.