Table 1.

Medline (Ovid) search strategy

Search term/line number	Conceptual term of interest	Search term entered into Ovid-Medline	Number of hits
1	Mental disorders	psychiatric.ti. OR “mental disorder”.ti. OR “mental disorders”.ti. OR “mental illness”.ti. OR “mentally ill”.ti.	83 986
2	Inpatient psychiatric settings	Exp “Psychiatric hospitals”/ OR Exp “hospital Psychiatric Department”/ OR “Psychiatric treatment center”.mp. OR “Psychiatric Hospital”.mp. OR “psychiatric unit”.mp. OR “psychiatric units”.mp. OR “Mental Institution”.mp. OR “Mental Hospital”.mp. OR “Psychiatric Department”.mp. OR “Psychiatric treatment centers”.mp. OR “Psychiatric Hospitals”.mp. OR “Mental Institutions”.mp. OR “Mental Hospitals”.mp. OR “Psychiatric Departments”.mp. OR “Psychiatric Ward”.mp. OR"psychiatric inpatient”.mp. OR “psychiatric inpatients”.mp.	41 507
3	Inpatient psychiatric admission	“psychiatric hospitalization”.mp. OR “psychiatric hospitalizations”.mp. OR “psychiatric readmission”.mp. OR “psychiatric readmissions”.mp. OR “psychiatric rehospitalization”.mp. OR “psychiatric rehospitalizations”.mp. OR “psychiatric admission”.mp. OR “psychiatric admissions”.mp	2905
5		1 or 2 or 3	110 553
6	Patient readmission	Exp “Patient Readmission”/	14 332
7	Readmission	Readmission*.mp. OR readmitted.ti.	28 315
8	Rehospitalisation	Rehospitali*.mp.	5515
9	Unnecessary admissions	“Unnecessary admission”.mp. OR “preventable hospitalizations”.mp. OR “preventable hospitalization”.mp.	315
10		6 or 7 or 8 or 9	31 946
11		5 and 10	1747