Fig. 1

Item threshold map in community-dwelling adults in the US. The item threshold map shows the hierarchy of the item difficulty levels, with the easiest item on top (item 11 “I've been able to make up my own mind about things”) and the hardest item at the bottom (item 3 “I've been feeling relaxed”). The horizontal logit ruler demonstrates the person's ability level of positive mental health from low ability on the left to high ability on the right