I'm looking for a knife that doesn't need to be regularly sharpened. The knife is for someone who has damaged wrists, and they find it difficult to have to continuously sharpen their knife.
IF ceramic and/or serrated knives do not work as a solution, here are the points for choosing a steel knife that will need less frequent sharpening.
A good starting point is choosing a knife made from a relatively hard (60-62 HRC) AND high wear resistance steel - VG-10 (not bargain basement grade VG-10 though: there seems to be much that can go wrong in making a knife from that steel), or Aritsugu's A-type steel, are well known to be good choices for that purpose.
The key is who eventually sharpens it (can be another person, maybe a professional) has to sharpen it properly - no wire edge. no overheating. intelligent choice of sharpening angles to match knife and user. advising the user on what to do and do not do with it.
Also, sharpening it when it is new can be advisable: Very few knives come with an optimal edge when they are new.
Alternatively, a knife that integrates well with a sharpening aid made or endorsed by the same manufacturer (Wusthof and Global do offer such) could work - the sharpening by these devices is not ideal but acceptable for some.
Don't believe the marketing - any knife will dull after some use.
But... You don't need to sharpen knives every time! You don't need to shave with your cooking knives. For real cooking work to be done it's enough just to hone (to fine the cutting edge) with sharpening steel. Look at https://www.youtube.com/watch?v=Nd7r-3RGpJA
And best of all: 3-5 strokes is enough.
As others have pointed out, harder steels will be better at holding an edge, as will ceramic knives. May I suggest though: let the knive be sharpened by a professional? Most week markets or similar have a "knife guy" who will sharpen your knives for a few dollars/euros a piece. And you don't need to do this every month. Every quarter of half year is probably way more than a home cook would need. Inbetween, use a honing rod to keep the edge sharp.
For the average knife and user, stay away from "high carbon steel," as they tend to need sharpening and "touching up" relatively more frequently. Standard stainless steel tends to be relatively more brittle. A blade made from what used to be called "chromalloy" (chromium/molybdenum/vanadium steel) is most likely your best option, holding an edge better than high carbon steel and being less brittle than stainless.
What will the knife be used for? Cooking/prep work? Self defense? Daily carry? Hunting? All need to factor into blade choice.
One parting observation: Use of a ceramic "steele" to touch up the blade might be a better choice if the user has limited mobility. Just use a lighter touch than with a steel Steele.
Just my $0.02
For more than 30 years I have made forged stainless steel knives that hold an edge far longer than other stainless knives and will out-cut carbon steel knives forged or otherwise, and sharpen easily. Of course knife manufacturers and knife makers have tried to keep this information hidden, gee I wonder why? They're not cheap, not made in china. But in the words of many o my customers, "Worth every penny." I have published my edge testing results on my website- seanmcwilliamsforge.com and yes, I do make kitchen knives.