People who work from home face a particular set of focus challenges that don't tend to distract people in the workplace. Just being in your home is a distraction if you are prone to noise from children, barking dogs, activity in your neighborhood, etc.
Here are a few things you can do to help your remote working stay focused while working from home:
1. Have a discussion up front about your expectations for their performance while working at home. Make sure they understand that it's about getting results, not clocking hours. Make sure they understand your expectations and the support they have access to so they can be as productive as people in the workplace.
2. Make sure, as best as possible, that they are working in a dedicated, uncluttered work area. While the 'dedicated' part is not always possible, being uncluttered and free of household debrie can have huge benefits for the person who is easily distracted.
3. Insist that they keep a schedule of work assignments. If they plan out their work time, it will be easier for them to justify attending to domestic things that arise.
4. Have them send you updates on their work at pre-agreed times. This way, you will know how far they have gotten with assignments without obsessing over the fact that they are not in the office.
5. Schedule phone or video updates throughout the day. I suggest no more than 3 (morning, before lunch, end of day). Calling them every 30 minutes makes you their biggest distraction and sends a very clear message that you do not trust them to work independently.
Other than these tips, treat your remote workers the same as you treat your workplace employees. With technology today, most everyone is capable of working from another location or on the go without being unproductive or cheating their employer out of a full day's work. If you have hired the right people, you should not see any difference in productivity.