I am a registered nurse working in a public hospital. Recently the hospital notified us that rosters would be changed, that have been in place for some time. Can they just decide?

In short, no, and disappointingly these types of unilateral changes arise too often without regard to collective or individual worker rights. Clause 6 (Introduction of Change) in the Public Health System Nurses’ and Midwives’ (State) Award sets out a number of examples that would require notification to employees and the Association to trigger consultation. One such situation is where: “… the alteration of hours of work for a … group of employees” is sought. Consultation is required to identify likely impacts, as well as measures that could mitigate any adverse effects. A good starting point for any discussion, of course, is always why the change is necessary.