An economic change? As an a single example of one?

Generally speaking, WWI threw the Ottoman economy into chaos. The Ottoman military requisition system was largely based on confiscation from civilian stocks. Both in general and in their specific practice this was incredibly inefficient. One such example was the mass requisition of food, which led to the "Great Famine of Mount Lebanon", which caused the death by starvation of about half of the population of Mount Lebanon.

Though it wasn't caused by WWI per se, the war severely affected the ability of the Ottomans to deal with the especially bad 1915 locust plague in the Levant.

I'm less familiar with the history of the core Turkish areas of Anatolia, but the Ottoman decision to mobilize their forces long before the eventual declaration of war also wreaked havoc on the Ottoman economy.

Those are basically some of the examples I can think of off the top of my head, are there any more specific areas you're interested in?