This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

(1) To determine the effectiveness of outreach services on ICU admission patterns of adult patients who deteriorate on general wards.

(2) To determine the impact of outreach services on hospital mortality rates and length of hospital stay.

(3) To identify within included studies adverse events (unexpected cardiac or respiratory arrest) and death in hospital before and after the introduction of outreach services.