Timing of surgery following SARS-CoV-2 infection: country income analysis.

Our analysis of the optimal timing of surgery following SARS‐CoV‐2 infection was based on data for 140,231 patients from across 116 countries [1]. Postoperative mortality rates are higher in low‐ and middle‐income countries (LMICs) than in high‐income countries (HICs) [2, 3], so the relationship between SARS‐CoV‐2 infection status and mortality could be confounded by country income. Therefore, we included country income (high vs. low/middle) as a factor in our adjusted models.

Drs Lobo and Devys [4] suggest that a further sub‐group analysis by country income would be helpful in order to ensure our findings are robust across all settings. We have produced sub‐group analyses by country income replicating the methodology of the original analysis [1]. Overall mortality was lower in HICs than in LMICs; 1116/91,458 (1.22%) vs. 1035/48,679 (2.13%), respectively, p < 0.001. Mortality was higher in patients with pre‐operative SARS‐CoV‐2 infection than in patients who did not have SARS‐CoV‐2 infection in both HICs 68/1450 (4.69%) vs. 1048/90,008 (1.16%), p < 0.001 and LMICs 110/1675 (6.57%) vs. 925/47,004 (1.97%), p < 0.001. Adjusted mortality rates in patients in HICs and LMICs with pre‐operative SARS‐CoV‐2 infection were lowest in those patients whose diagnosis was ≥ 7 weeks before surgery (Table 1).

Table 1

Unadjusted and adjusted 30‐day postoperative mortality rates by country income sub‐group. Values are proportion (fraction) or adjusted mortality rate (95%CI).

Pre‐operative SARS‐CoV‐2 by timing of pre‐operative diagnosis	Unadjusted mortality rates a		Adjusted mortality rates (95%CI) b
	High‐income countries	Low‐ and middle‐income countries	High‐income countries	Low‐ and middle‐income countries
No diagnosis	1.16% (1048/90,008)	1.97% (925/47,004)	1.18% (1.11–1.25%)	2.01% (1.89–2.13%)
0–2 weeks	8.03% (37/461)	9.90% (67/677)	3.31% (2.29–4.34%)	5.57% (4.30–6.85%)
3–4 weeks	6.92% (11/159)	6.95% (21/302)	4.29% (1.99–6.60%)	4.60% (2.76–6.45%)
5–6 weeks	6.67% (9/135)	4.71% (9/191)	5.54% (2.38–8.71%)	3.35% (1.27–5.43%)
≥ 7 weeks	1.58% (11/695)	2.57% (13/505)	1.23% (0.53–1.93%)	2.02% (0.96–3.08%)

Mortality data were missing in high‐income countries for 76 patients with no SARS‐CoV‐2 diagnosis and 1 patient with SARS‐CoV‐2 diagnosis at ≥ 7 weeks; and in low‐ and middle‐income countries for 16 patients with no SARS‐CoV‐2 diagnosis and 1 patient with SARS‐CoV‐2 diagnosis at ≥ 7 weeks.

Model adjusted for age; sex; ASA physical status; revised cardiac risk index; respiratory comorbidity; indication for surgery; grade of surgery; and urgency of surgery. Full unadjusted and adjusted models are presented in online Supporting Information Tables S1 and S2.

These country income sub‐group analyses indicate that our recommendation that, whenever possible, surgery should be delayed for at least 7 weeks following SARS‐CoV‐2 infection is applicable to both HICs and LMICs.

Table S1. Unadjusted and adjusted model for 30‐day postoperative mortality in high‐income countries. Values are OR (95%CI).

Table S2. Unadjusted and adjusted model for 30‐day postoperative mortality in low‐ and middle‐income countries. Values are OR (95%CI).

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Appendix S1. CovidSurg Collaborative, GlobalSurg Collaborative writing group.

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