Table 2.

Summary of key findings from studies reporting on psychiatric illness and incidence, characteristics and survival of OHCA.

Author, Year of publication	Study participants [number with psychiatric illness]	Factors adjusted for in statistical models	Key findings
Empana, 200623	2,228 Cases/4,164 Controls [300 /327]	Smoking, alcohol use, hypertension, diabetes, history of MI and CHF	•Patients with depression had higher odds of OHCA than patients without depression: OR 1.43; 95% CI 1.18–1.73 •Excess risk in patients with more severe depression: OR 1.77; 95% CI 1.28–2.45a
Wissenberg, 201429	19,372 [2,674]	NA	•Females were more likely to have a history of psychiatric illness than males (17.3% s versus 12.1%)
Ko, 201627	9,882 [389]	Age, sex, income, comorbidities, EMS response time, location of arrest, witness status and bCPR	•Patients with depression had higher risk of PEA rhythm than patients without depression for all ages: OR, 1.55; 95% CI, 1.07–2.26 •No statistically significant difference in patients over 65 years: OR 0.86; 95% CI 0.52–1.42
Rajan, 201628	13,860 [2,146]	Age, sex, comorbidities, location of arrest, witness status, bCPR, time from recognition of arrest to rhythm analysis by the EMS, and year of arrest	•Patients with history of psychiatric illness had lower odds of rhythm conversion from non-shockable to shockable than patients without history of psychiatric illness: OR 0.66; 95% CI 0.55–0.79
Ishida, 201926	649 [49]	NA	Patients with versus without psychiatric illness were more likely to have: •An arrest in public place: 42.0% versus 24.5% •Comorbidities :81.2 % versus 61.2%
Allan, 201824	608 [117]	NA	Among patients < 45yrs: •Prevalence was lowest among 2–24 year olds •Psychiatric illness was more common in females: 27% versus 18%
Barcella, 2019 6	27,523 [4,772]	Age, sex and year of arrest	Patients with versus without psychiatric illness have: •Lower 30-day survival: OR 0.37; 95% CI 0.32–0.43 •Lower odds of shockable rhythm OR 0.37, 95% CI 0.33–0.40
Ishida, 20207	2,631 [157]	Age, sex, comorbidities, witness status, location of arrest	Patients with schizophrenia or mood disorders have: •Lower survival to discharge: 7.6% versus 10.2 •Lower odds of shockable rhythm: OR 0.27; 95% CI 0.13–0.55
Hulleman, 202025	1,404 [120]	NA	•Prevalence of depression higher in OHCA occurring at home: 9.6% versus 5.7% at public •Patients with history of depression less likely to have initially shockable rhythm: 6.4% versus 10.8%
Barcella, 2021, Denmark30	35,017 Cases/175,085 Controls [802 /4,009]	NA	•Cases with schizophrenia had higher rates of OHCA than matched controls: HR 4.49, 95% CI 4.00–5.10 •Cases with bipolar disorder had higher rates of OHCA than matched controls: HR 2.74, 95% CI 2.41–3.13

bCPR: Bystander Cardiopulmonary Resuscitation; CHF: Congestive Heart failure; CI: Confidence Interval; EMS: Emergency Medical Services; HR: Hazard ratio; MI: Myocardial infarction; OHCA: Out-of-hospital Cardiac Arrest; OR: Odds Ratio; ROSC: Return of Spontaneous Circulation; PEA: Pulseless electrical activity (classified as non-shockable rhythm).

^aSevere depression defined by depression with history of referral to a mental health clinic and/or hospitalisation for depression in the year before OHCA.