The phrase "affirmed his decision" is correct and usable in written English.
You can use it when someone confirms or reinforces a choice or conclusion they have made.
Example: "After much consideration, he affirmed his decision to pursue a career in medicine."
Alternatives: "reiterated his choice" or "confirmed his decision."
An appeals court affirmed his decision.
NAMPA, Idaho Floridada running back Jeff Demps affirmed his decision to focus on a track career by skipping the N.F.L. combine last month.
Administrative Law Judge Joel A. Linsider recommended last May that the wholesale prices Verizon charges its competitors be cut significantly, and the commission affirmed his decision yesterday.
But Carlos Cuevas, a Chicago immigration judge with a far-from-bad reputation, ordered them back to Macedonia, and the appeals board — actually just one person — affirmed his decision.
The three-justice panel affirmed his decision and agreed with his findings ― there was indeed evidence of an informant program in Orange County's jails, and it was appropriate to recuse Rackauckas' prosecutors from Dekraai's case.
In time for last November's elections, the judge re-affirmed his 1983 decision and extended it to students at all Westchester campuses.
Jamal, however, affirms his gayness, or rather his decision to sleep with whomever he wants, when he wants.
When Spikes returned home for the first time since starting school, he felt re-affirmed in his decision to attend Cornell.
News about the shark attack affirmed her decision to only dip her toes in the water.
On 31 August, the commission summarily affirmed its decision to disqualify Shwe Maungwithout appearing to glance at his documentation.
It wasn't surprising that Bettman affirmed the decision: if he hadn't, he would have lost the trust of on-ice officials and his staffers.
