How frequently must a disaster drill be conducted?

Conducting a disaster drill at least once every three months is essential for ensuring that staff and residents in nursing care institutions are adequately prepared for emergencies. This frequency allows for regular reinforcement of training and procedures, helping to maintain a high level of readiness among all personnel. A quarterly schedule strikes a balance that is manageable for staff while ensuring that skills do not become stale over time.

Regular drills help identify any potential weaknesses in the institution's emergency response plan and provide opportunities for staff to practice their roles in a controlled environment. This practice is crucial in high-stakes situations where lives are at risk, making the confidence and competence of the team in an emergency response scenario vital.

The other options suggest frequencies that may either overwhelm staff, such as conducting drills more than once a month, or may not provide sufficient training, as with the option of only conducting them once a quarter. Thus, the established standard of holding drills at least once every three months is both practical and effective in preparing a facility for potential disasters.