Off the bat, we can of course say that the design itself looks old, outdated and dark.
But the slightly dated nature of the design is really not the issue! You don’t have to have a gorgeous, stunning website for it to be effective.
The bigger problem is that the website is “scattered” in its design. There’s no natural “eye trail”, no natural direction on where to look and how to read the page. It is just a bunch of different things thrown on to fit.
A prospective new patient might look at this, not have it be clear what they should do next, should they send an e-mail? (Why would they do that?) Should they call? Is there anything for new patients? Unanswered questions lead to confusions – not decisive action.
A website visitor is very likely to reach this page, and bounce off the website to look elsewhere.