Update: 2nd September 2016
There was a surprising amount of support for this post on Twitter, mixed in with anticipated criticism from those who just told me Excel is rubbish. What's interesting is that very few of the latter group could suggest a useable alternative for data entry (and some had clearly not read my post and thought I was advocating using Excel for data analysis). And yes, I don't regard Access as a usable alternative: been there tried that, and it just induced a lot of swearing.
There was, however, one suggestion that looks very promising and which I will chase up
@stephenelane suggested I look at REDcap.
Website here: https://projectredcap.org/
Meanwhile, here's a very useful link on setting up Excel worksheets to avoid later problems that came in via @tjmahr on Twitter
Update 4th October 2016
Just to say we have trialled REDCap, and I love it. Very friendly interface. Extremely limited for any data manipulation/computation, but that doesn't matter, as you can readily import/export information into other applications for processing. It's free but institution needs to be signed up for it: Oxford is not yet fully functional with it, but we were able to use it via a colleague's server for a pilot.