One good way is to actually measure the current through VDD with no load conditions. In case, the pass transistor is taking a lot of current,just measure the current through the source/drain of the MOS.
Programmable Output voltage will be determined by the resistor ratios across the Pass transistor. Hence, the quiscient current should more or less be the same.
It is right when you measure the quiscent current through Vdd at no load condition. But you should check current when Vdd is around dropout voltage value and at different temp conditions.