Yes, Nathan, in terms of the first quarter and utilization seasonality, I would say, common, this is leap year. So all of things being equal, you would have had a higher trend in February because of leap year. But then there was other workday seasonality over the quarter such that we would say, in total, there's really not a seasonality impact and relatively consistent with the prior year. And those are all things we would have anticipated in our initial plan and then the guidance we gave for the first quarter. .
In terms of acuity, I would say aside from just again, the impact of the utilization management changes, where we always anticipated that effectively lower severity short-stay events would end up moving into the inpatient cost category versus the previous observation, which we reported ER. So that, we certainly are seeing, as I said, we need some additional time to see how the unit cost ultimately develops.
Some of the early indicators do suggest those are on average lower unit cost, which makes sense, but we need, again, because of the change disruption, just some more time to fully evaluate that. But aside from that, I would say, again, limited visibility because of some of the disruption to the more recent periods in terms of claims submissions. But with what we do have, I'd say nothing that has caused us any concern from an acuity standpoint.
In terms of EPS seasonality, I would say the biggest driver of the differences you see every year and the disproportionate first half proportion is going to be just, in general, the lower proportionate contribution of the MA insurance business to the total than prior years. And so you're going to have PPD, which is disproportionately first half of the year, obviously impacting the first quarter, investment income and all those other things that are developing as they would in normal course, are just going to result in more earnings in the first half of the year just because MA proportionally is much lower, obviously, given the overall EPS and earnings expectation for the year.
Admin certainly has some seasonality to it, but I would say nothing unusual as we think about the year. The only thing that we did see because of the lower enrollment this year, you do see some positive impact in commissions. That is partly what we're seeing in the first quarter. And so that, based on the level of growth we would expect could develop a little bit differently. Again, those are things we will plan for. But aside from that, I see nothing in particular to call out in terms of admin seasonality relative to typical.