Incidence, Risk Factors, and Outcomes of Perioperative Atrial Fibrillation following Noncardiothoracic Surgery: A Systematic Review and Meta-Regression Analysis of Observational Studies

Table 1

Study quality assessment: meta-regression and sensitivity analysis of various subgroups (as categorical variable).

Risk factor or outcome	Study characteristics (number of studies)	Summary estimate	95% CI	I^2	Meta-regression
Age	Coefficient (SE)	value
Study type	Retrospective (9) [19–23, 26–29]	3.75	0.75–6.76	90	0.6155	0.8651
	Prospective (2) [24, 25]	5.03	2.97–7.09	0	(3.6220)
Quality of study	Poor-moderate (1) [20]	14.34	−11.37–40.05	—	−0.3148	0.9486
	Good (10) [19, 20–29]	3.97	1.57–6.38	89	(4.8794)
Outcome defined	Yes (7) [19, 21, 22, 24, 25, 27, 28]	4.58	2.08–7.08	88	0.3634	0.9250
	No (4) [20, 23, 26, 29]	3.12	−4.31–10.55	83	(3.8607)
Sample size >1000	Yes (4) [21, 25–27]	3.11	−0.41–6.62	94	1.9924	0.4748
	No (7) [19, 20, 22–24, 28, 29]	4.93	1.51–8.34	67	(2.7880)
Surgery type	Transplant (3) [25, 26, 29]	3.04	−4.03–10.11	90	−1.6709	0.6740
	Nontransplant (8) [19–24, 27, 28]	4.42	1.68–7.17	86	(3.9716)
Gender
Study type	Retrospective (9) [19–23, 26–29]	1.07	0.42–1.72	87	−0.1621	0.8230
	Prospective (2) [24, 25]	1.15	0.66–1.64	0	(0.7248)
Quality of study	Poor-moderate (1) [20]	0.68	−0.26–1.62	—	−0.5386	0.5592
	Good (10) [19, 21–29]	1.14	0.55–1.72	86	(0.9223)
Outcome defined	Yes (7) [19, 21, 22, 24, 25, 27, 28]	1.43	1.33–1.52	0	0.4614	0.5366
	No (4) [20, 23, 26, 29]	0.56	−0.01–1.12	34	(0.7465)
Sample size >1000	Yes (4) [21, 25–27]	1.07	0.29–1.86	95	−0.3247	0.4981
	No (7) [19, 20, 22–24, 28, 29]	1.02	0.46–1.57	0	(0.4793)
Surgery type	Transplant (3) [25, 26, 29]	0.80	−0.04–1.63	83	−0.3795	0.5944
	Nontransplant (8) [19–24, 27, 28]	1.43	1.33–1.53	0	(0.7126)
Hypertension
Study type	Retrospective (8) [19, 21–23, 26–29]	1.15	1.07–1.22	0	−0.1036	0.8490
	Prospective (2) [24, 25]	1.24	0.75–1.74	0	(0.5441)
Quality of study	Poor-moderate (0)	—	—	—	—	—
	Good (10) [19, 21–29]	1.15	1.08–1.23	0
Outcome defined	Yes (7) [19, 21, 22, 24, 25, 27, 28]	1.15	1.08–1.23	0	−0.8519	0.1879
	No (3) [23, 26, 29]	2.81	−0.77–6.39	0	(0.6469)
Sample size >1000	Yes (4) [21, 25–27]	1.15	1.08–1.23	0	−0.2608	0.3738
	No (6) [19, 22–24, 28, 29]	1.32	0.50–2.13	0	(0.2933)
Surgery type	Transplant (3) [25, 26, 29]	1.24	0.74–1.75	0	−0.0418	0.9409
	Nontransplant (7) [19, 21–24, 27, 28]	1.15	1.07–1.23	0	(0.5639)
Cardiac disease
Study type	Retrospective (7) [19, 21–23, 26, 28, 29]	2.79	0.17–5.41	92	1.3910	0.0545
	Prospective (2) [24, 25]	1.32	0.16–2.49	55	(0.7236)
Quality of study	Poor-moderate (0)	—	—	—	—	—
	Good (9) [19, 21–26, 28, 29]	2.30	0.28–4.31	93
Outcome defined	Yes (6) [19, 21, 22, 24, 25, 28]	2.15	−0.16–4.46	95	0.0043	0.9956
	No (3) [23, 26, 29]	3.28	−1.90–8.46	27	(0.7790)
Sample size >1000	Yes (3) [21, 25, 26]	3.86	0.90–6.82	92	0.7579	0.1808
	No (6) [19, 22–24, 28, 29]	0.94	0.29–1.58	0	(0.5663)
Surgery type	Transplant (3) [25, 26, 29]	2.94	−0.63–6.52	13	0.9274	0.2304
	Nontransplant (6) [19, 21–24, 28]	2.01	−0.42–4.44	96	(0.7732)
Diabetes mellitus
Study type	Retrospective (8) [19, 21–23, 26–29]	0.97	0.89–1.05	0	0.7277	0.4019
	Prospective (1) [24]	0.61	−0.70–1.92	—	(0.8681)
Quality of study	Poor-moderate (0)	—	—	—	—	—
	Good (9) [19, 21–24, 26–29]	0.97	0.89–1.05	0
Outcome defined	Yes (6)[19, 21, 22, 24, 27, 28]	0.97	0.89–1.05	0	−0.2032	0.7579
	No (3)[23, 26, 29]	1.51	0.14–2.88	0	(0.6595)
Sample size >1000	Yes (3)[21, 26, 27]	0.97	0.89–1.05	0	−0.2644	0.5052
	No (6) [19, 22–24, 28, 29]	0.94	0.17–1.71	0	(0.3968)
Surgery type	Transplant (2) [26, 29]	1.48	−0.51–3.48	0	0.3992	0.5901
	Nontransplant (7) [19, 21–24, 27, 28]	0.97	0.89–1.05	0	(0.7410)
Cardiac complications
Study type	Retrospective (5) [19, 21, 22, 28, 29]	5.71	−0.18–11.61	83	0.3609	0.6949
	Prospective (1) [24]	4.34	−1.11–9.79	—	(0.9292)
Quality of study	Poor-moderate (0)	—	—	—	—	—
	Good (6) [19, 21, 22, 24, 28, 29]	5.44	0.49–10.39	82
Outcome defined	Yes (5) [19, 21, 22, 24, 28]	5.41	0.36–10.46	85	−0.7377	0.6474
	No (1) [29]	11.58	−83.6–106.76	0	(1.6127)
Sample size >1000	Yes (1) [21]	10.51	9.63–11.39	—	0.9718	0.0023
	No (5) [19, 22, 24, 28, 29]	3.18	0.54–5.82	0	(0.3193)
Surgery type	Transplant (1) [29]	11.58	−83.60–106.76	—	0.7377	0.6474
	Nontransplant (5) [19, 21, 22, 24, 28]	5.41	0.36–10.46	85	(1.6127)
Mortality
Study type	Retrospective (6) [19, 20, 22, 26–28]	3.58	0.14–7.02	0	—	—
	Prospective (0)	—	—	—
Quality of study	Poor-moderate (1) [20]	2.47	−22.62–27.56	—	−0.7977	0.6530
	Good (5) [19, 22, 26–28]	3.60	0.13–7.08	0	(1.7743)
Outcome defined	Yes (4) [19, 22, 27, 28]	3.20	−1.16–7.57	0	0.4607	0.6670
	No (2) [20, 26]	4.21	−1.39–9.81	0	(1.0705)
Sample size >1000	Yes (2) [26, 27]	6.51	−3.79–16.81	22	1.2296	0.0934
	No (4) [19, 20, 22, 28]	2.69	−1.67–7.06	0	(0.7329)
Surgery type	Transplant (1) [26]	4.30	−1.44–10.04	—	−0.2072	0.8651
	Nontransplant (5) [19, 20, 22, 27, 28]	3.18	−1.12–7.48	0	(1.2196)

Study quality scores were obtained from the Ottawa–Newcastle quality assessment [16]. Study was considered good when assigned score was equal 9. For respiratory complications and Stroke, meta-regression analysis not conducted due to inadequate number of studies.