I'm running a hierarchical logistic regression to find out if/how block 2 improves the predicted power in addition to block 1, so what I need is the value that is equal to ΔR2 in blockwise multiple regression.

Is it right that the difference from the 2-log-likelihood (2-ll) of my second block and the 2-ll from the first block tells me about the gain of predictive power? How can I find out if this gain is significant?

Thanks in advance for your help!