Table 2.

Systematic review for outcomes of included studies

Study	Location	Study design	Years	Total cap population	Inclusion criteria	Exclusion criteria	Follow-up	Outcomes
Gundlund 2019 [8]	Netherlands	Database	1996–2016	269,432	Age ≥ 18 years old, patients admitted with infection (subgroup with pneumonia)	Age > 100 years old, previous diagnosis of AF, death during hospital admission	365 days	12 months of mortality: aHR 1.42 (95% CI 1.37–1.47)
Mandal 2011 [28]	United Kingdom	Database	2005–2007	4408	Age ≥ 18 years old, diagnosis of CAP defined by ICD-10 codes	HAP, admission or transfer from a health-care facility; post-operative pneumonia; HIV	90 days	90-day mortality: aOR 2.39 (95% CI 1.65–2.19, p < 0.0001)
Pieralli 2019 [22]	Italy	Prospective	2013–2016	468	Age ≥ 18 years old, sinus rhythm confirmed by ECG on admission, no previous documented episodes of AF, diagnosis of CAP defined by clinical and radiological evidence	HAP, immunocompromised or refused or unable to give their consent	9.5 + 5.1 days (mean, SD)	In-hospital mortality rate, newAF VS controls: 18.8% vs 11.4%, p = 0.16
Ruiz 2021 [25]	Spain	Prospective	2002–2019	1,092	Hospitalized pneumococcal CAP diagnosed by clinical, radiological, and microbiological evidence	Pneumonia in the previous 3 months and pre-existing AF	180 days	6 months of mortality rate, newAF VS controls: 17.9% versus 2.9%, p < 0.001
Pieralli 2021 [24]	Italy	Prospective	2016–2018	1,266	Age > 18 years old; diagnosis of CAP defined by clinical and radiological evidence	HAP, immunocompromised or refused or unable to give their consent	30 days	30-day mortality: HR 1.04 (95% CI 0.64–1.5, p = 0.99)

Legend: aHR adjusted Hazard Ratio, aOR adjusted Odds Ratio, AF Atrial Fibrillation, newAF new-onset Atrial Fibrillation, CI Confidence Intervals, ECG Electrocardiogram, HAP Hospital-Acquired Pneumonia, HR Hazard Ratio, HIV Human Immunodeficiency Virus, ICD International Classification of Diseases, SD standard deviation