Geographical Association Between Basic Life Support Courses and Bystander Cardiopulmonary Resuscitation and Survival from OHCA in Denmark

Figures & data

Table 1 Summary Statistics of Out-of-Hospital Cardiac Arrest and Basic Life Support Course Participation in Denmark, from 2016 to 2019

	Out-of-Hospital Cardiac Arrest				BLS Course Certificates
	Total Number [#]	30-Day Survival Rate [%]	Survival Per 100,000 Inhabitants	Bystander CPR Rate [%]	Number of Verified Individuals
2016	4547	13.5	10.2	78.2	197,127
2017	4811	12.8	10.2	78.0	203,261
2018	4723	11.7	9.2	78.8	159,971
2019	4468	14.4	10.6	80.0	144,281

Notes: All OHCAs not witnessed by the EMS personnel were included. OHCAs located at nursing homes and other healthcare staffed institutions were included in the current data.

Abbreviations: CPR, cardiopulmonary resuscitation; BLS, basic life support; OHCA, out-of-hospital cardiac arrest.

Figure 1 Modified Consort Flow Diagram.

Notes: *Daytime – working hours is defined as 08.00–16.00. Night-time – out of offices hours is defined as 16.00–08.00. CONSORT figure adapted from Falci SGM, Marques LS. CONSORT: when and how to use it. Dental Press J. Orthod. 2015;20(3):13-15. Copyright: © 2015 Falci and Marques. Creative Commons Attribution License.³⁵

Figure 2 Incidence proportion of number OHCAs per 100,000 inhabitants, 30-day survival BLS course participation rates and bystander rates at OHCA in Denmark at municipal level from January 1 2016 to December 31 2019.

Notes: Incidence proportion (%) between 2016 and 2019 of (a). Out-of-hospital cardiac arrest per 100,000 inhabitants; (b). 30-day survival from out-of-hospital cardiac arrest; (c). Basic life support course participation rate; (d). Rates of bystander cardio pulmonary resuscitation at out-of-hospital cardiac arrest at municipal level, in Denmark from January 1 2016 to December 31 2019.

Abbreviations: CPR, cardiopulmonary resuscitation; BLS, basic life support; OHCA, out-of-hospital cardiac arrests.

Table 2 Global Moran’s I Summary Statistics

Model Variable	I	E (I)	SD (I)	Z	p value
Number of OHCA	0.344	−0.0103	4.555	0.00606	0.000
30-day survival rate	0.090	−0.0103	1.3345	0.00567	0.091
BLS course participation rate	0.590	−0.0103	7.634	0.00619	0.000
Bystander CPR rate	0.297	−0.0103	3.893	0.00621	0.000

Abbreviations: BLS, basic life support; CPR, cardiopulmonary Resuscitation; OHCA, out-of-hospital cardiac arrest.

Figure 3 Map of significant geographical clusters of (a) number OHCA per 100,000 inhabitants; (b) 30-day survival; (c) BLS course participation rates and (d) bystander CPR rates at OHCA at municipal level from 2016 to 2019.

Notes: High-High [red]: Indicates a significant geographical cluster within the municipality with high value in the municipality and high value in a municipality next to it (neighboring), not to be expected by chance. Low-Low [blue]: Indicates a significant geographical cluster within the municipality with low value in the municipality and low value in a municipality next to it (neighboring), not to be expected by chance. Low-High [light red]: Indicates a significant geographical cluster within the municipality with low value in the municipality and high value in a municipality next to it (neighboring), not to be expected by chance. Low-High [light blue]: Indicates a significant geographical cluster within the municipality with high value in the municipality and high value in a municipality next to it (neighboring), not to be expected by chance.

Abbreviations: CPR, cardiopulmonary resuscitation; BLS, basic life support; OHCA, out-of-hospital cardiac arrest.

Table 3 Odds Ratios and Summary Statistics from Non-Spatial and Spatial Analysis

Variables	Non-Spatial						Spatial
	Not Adjusted for Over Dispersion						Adjusted for Over Dispersion
	OR Crude	CI 95%	p value	OR^▼ Adjuste d	CI 95%	p value	Dispersion parameter	CI 95%	p value	OR	CI***	ρ	τ2
BLS course proportion OHCA in all hours
Bystander CPR$	1.37	1.20;1.57	<0.001*	1.33	1.13;1.56	0.001	2.53**	1.03;1.72	0.034*	1.34	1.02;1.76	0.052	0.063
30-day survival	0.71	0.60;0.84	<0.001*	0.98	0.80;1.22	0.879	0.99	-	-	0.99	0.79;1.24	0.369	0.005
BLS course proportion OHCA in out-of-office hours
Bystander CPR$	1.47	1.22;1.76	<0.001*	1.48	1.18;1.87	0.001*	1.56**	1.12;1.96	0.007*	1.43	1.09;1.89	0.2692	0.0229
30-day survival	0.65	0.51;0.82	0.006*	0.95	0.70;1.30	0.74	0.93	-	-	0.97	0.70;1.33	0.391	0.006
BLS course proportion OHCA in public locations
Bystander CPR$	1.06	0.76;1.47	0.726	1.13	0.73;1.75	0.580	1.21	-	-	1.14	0.71;1.78	0.380	0.009
30-day survival	0.57	0.43;0.74	<0.001*	0.85	0.60;1.20	0.358	1.16	-	-	1.01	0.72;1.44	0.391	0.006

Notes: ^▼Models with bystander CPR as outcome is adjusted for [municipal] disposable income per person in quartiles, mean [municipal] age and response time [minutes]. Models with 30-day survival as outcome is adjusted for mean [municipal] disposable income per, mean [municipal] age, mean [municipal] Charlson Comorbidity Index and for Initial rhythm, mean [municipal]. For the subgroup analysis on OHCAs in public locations, the mean response time variable and the variable containing data concerning municipal levels of comorbidity (mean Charlson comorbidity index) was treated as a categorical variable ranging from 1–4. $ Prior to arrival of EMS personnel. *Significant within a 95% confidence interval. **Residual deviance divided with degrees of freedom is above 1.5 considered as over dispersion. ***Credible intervals.

Abbreviations: BLS, basic life support; CPR, cardiopulmonary Resuscitation; OHCA, out-of-hospital cardiac arrest.

Falci SGM, Marques LS CONSORT: when and how to use it. Dental Press J Orthod. 2015;20(3):13–15.

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