In terms of actual value, it's 39.05 direct hit rating per 1% direct hit.

If you're asking about stat weights, then it's about 8% stronger than determination point-for-point, but only in a vacuum. This game's stats don't work that way and are generally not nearly as relevant as people like to make them out to be because:

1) All of them are so close in value. Compared to, say, WoW where a secondary stat could be as much as 400% better than another, the biggest gap in FFXIV is ~60%.
2) Primary stats are so much stronger than secondaries you always choose ilvl over secondaries. (Tank accessories being an exception, or if you need to overmeld VIT for some reason on DPS accessories.)
3) You can't meld a stat on a piece of gear past a certain point.
4) There's so little choice in gear anyway. Two whole choices per slot! Except rings, where you have no choices and you just put in the 2 highest ilvl ones.