When I read documentations about quantum error correction, it generally speak about bit flip error, and phase flip on $|1\rangle$ state, so for example, let's say my initial state is $|\psi\rangle = a|0\rangle+b|1\rangle$, bit flip error correction $|\psi'\rangle = b|0\rangle+a|1\rangle$ or phase flip error correction $|\psi'\rangle = a|0\rangle-b|1\rangle$.
I'm wondering why the phase flip error correction $|\psi'\rangle = -a|0\rangle+b|1\rangle$ is never discussed? And why error correction codes don't correct this phase flip (at least these I have tested)? Is there a reason I'm not aware about ? Maybe this error never happens "in real life"?