An umbrella review of systematic reviews on the impact of the COVID-19 pandemic on cancer prevention and management, and patient needs

Institute of Social and Preventive Medicine, University of Bern, Switzerland
Meta-Research Innovation Center at Stanford (METRICS), Stanford University, United States
Epistudia, Switzerland
Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong
Department of Pathology and Laboratory Medicine, Stony Brook University, Long Island, United States
Stanford Prevention Research Center, Department of Medicine, Stanford University School of Medicine, United States
Department of Epidemiology and Population Health, Stanford University School of Medicine, United States

Apr 4, 2023

https://doi.org/10.7554/eLife.85679

Open access
Copyright information

Figures
Tables
Additional files

2 figures, 4 tables and 3 additional files

Figures

Figure 1

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Flowchart of identification, screening, eligibility, inclusion, and exclusion of retrieved studies*.

*In the search, we did not include any language restriction filter. However, during full-text screening we included only studies that were in English. **WHO COVID-19 database does not allow to specify the search by both date and month, and the search for this specific database is up to end-December 2022. Any full text (n = 0) that was eligible and published after November 29, 2022, was excluded.

Figure 2

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Visual summary.

CI, confidence interval.

Tables

Table 1

Characteristics of included systematic reviews.

Author, year of publication	Meta-analysis	Number of included studies	Countries*	Pre-pandemic controls	Cancer types	Aspects assessed	Last search
Adham et al., 2022	No	5	Globally	No	H&N	MT, O	15-Jul-20
Alkatout et al., 2021	No	16	Multiple countries, including US, TW, BE, NL, JP, IT, UK, AS, CA	Yes	ALL	DCS, RD	28-Dec-20
Alom et al., 2021	No	72	Multiple countries	No	All	MT, TL, O	1-Sep-20
Ayubi et al., 2021	Yes	34	Multiple countries	No	All	PSND, O	3-Jan-21
Azab and Azzam, 2021	No	51	Multiple countries	No	Glioma	MT	End of 2020
Bezerra et al., 2022	No	8	NP	No	ALL	TL	01-Apr-2021
Crosby and Sharma, 2020	No	45	NP	No/NS	H&N	MT	08-Apr-2020
de Bock et al., 2022	Yes	24	Multiple countries	Yes	ALL, BC	Delayed and/or canceled treatment Other aspects	21-Mar-2021
Dhada et al., 2021	No	19	Multiple countries, including IT, US, UK, NL	No	ALL	DCT, DCS, PSND, TL, FBD, SIA	1-Dec-20
Di Cosimo et al., 2022	Yes	56	Multiple countries	Yes	ALL	MT, DCT, TL, O	11-Dec-20
Donkor et al., 2021	No	11	Multiple countries, including CN, IR, BR, ZA	No	ALL	O	3-Aug-20
Fancellu et al., 2022	No	7	IT	Yes	CRC	DCS, RD	31-Jan-22
Ferrara et al., 2022	No	33	Multiple countries	Yes	CV	DCT, DCS, RD, RHPV	8-Feb-22
Gadsden et al., 2022	No	17	Multiple countries, including IN, SL, BA	Yes	ALL	DCT, O	15-Dec-21
Garg et al., 2020	No	212	Multiple countries	No	ALL	MT	2-May-20
Gascon et al., 2022	No	23	Multiple countries	No	H&N	MT, O	1-May-20
Hesary and Salehiniya, 2022	No	22	Multiple countries, including IT, UK, PG, NL, CN, IN, JP, TU, IR, SN	Yes	GA	MT, DCS, RD, PSND	31-Dec-21
Hojaij et al., 2020	No	35	Multiple countries	No	H&N, OTO	MT, TL, O	31-Dec-20
Jammu et al., 2021	No	19	Multiple countries	No	ALL	DCT, PSND, FBD	27-Aug-20
Kirby et al., 2022	No	56	Multiple countries	No	ALL	PSND, FBD, SIA	31-Mar-21
Legge et al., 2022	No	18	Multiple countries	No	ALL	PSND, FBD, SIA	25-May-22
Lignou et al., 2022	No	32	Multiple countries	Yes	PC	DCT, RD, TL	1-Aug-21
Lu et al., 2021	No	41^†	NP	No	ALL	TL	1-May-20
Majeed et al., 2022	No	60	Multiple countries	Yes, but NS	PC	DCT, RD, TL	3-Nov-21
Mayo et al., 2021	Yes	13	Multiple countries, including IT, AU, TW, US, FR, NL	Yes	ALL	DCT, DCS	10-Feb-21
Mazidimoradi et al., 2021	No	43	Multiple countries	Yes	CRC	MT, DCT, RD	1-Jun-21
Mazidimoradi et al., 2022	No	25	Multiple countries	Yes	CRC	DCS	1-Jun-21
Momenimovahed et al., 2021	No	55	Multiple countries	No	ALL	PSND	30-Jun-21
Mostafaei et al., 2022	No	22	Multiple countries	No	ALL	TL	1-Jun-21
Moujaess et al., 2020	No	88	Multiple countries	No	ALL	DCT, O	15-Apr-20
Muls et al., 2022	No	51	Multiple countries	No	ALL	PSND	1-Oct-21
Murphy et al., 2022	No	37	Multiple countries	No	ALL	TL	31-Mar-21
Ng and Hamilton, 2022	Yes	31	Multiple countries	Yes	BC	DCS, RD	1-Oct-20
Nikolopoulos et al., 2022	No	15	Multiple countries	Yes, but NS	GC	MT, DCT, RD, PSND	10-Feb-21
Pacheco et al., 2021	No	9	Multiple countries, including US, IT, CN, SP, UK, IR	No	ALL	DCT, O	NP
Pararas et al., 2022	Yes	10	Multiple countries	Yes	CRC	O	NP
Pascual et al., 2022	No	12	Multiple countries from low- and middle-income countries	Yes, but NS	Surgical Neuro-Oncology	MD, RD, TL, O	01-Sep- 2021
Piras et al., 2022	No	281	Multiple countries	No	ALL	MT, DCT, SIA, PSND	31-Dec-2021
Riera et al., 2021	No	62	Multiple countries	Yes	ALL	DCT	NP
Rohilla et al., 2021	No	6	IN	No	ALL	PSND, O	3-Feb-21
Salehi et al., 2022	No	16	Multiple countries	No	ALL	TL	1-Apr-21
Sarich et al., 2022	Yes	44	Multiple countries	Yes	NA	RF	5-Nov-20
Sasidharanpillai and Ravishankar, 2022	Yes	7	Multiple countries, including SL, IT, CA, SC, BE, US	Yes	CV	DCT, RD	1-Sep-21
Sun et al., 2021	No	6	IT, AM, UK	No	BC	MT	1-Feb-21
Tang et al., 2022	Yes	14	TU, CN, UK, IT, DN, AS, AU	Yes	CRC	O	12-Jan-22
Teglia et al., 2022a	Yes	39	Multiple countries	Yes	BC, CRC, CV	DCT, RD	12-Dec-21
Teglia et al., 2022b	Yes	47	Multiple countries	Yes	ALL	DCT	12-Dec-21
Thomson et al., 2020	Yes	54	NP	Yes	ALL	O	1-Jun-21
Vigliar et al., 2020	Yes	41^‡	Multiple countries	Yes	ALL	DCS, RD	30-Apr-20
Zapała et al., 2022	No	160	NP	No	ALL	DCT, PSND, TL	NP
Zhang et al., 2022	Yes	40	Multiple countries	No	ALL	PSND	31-Jan-22

*

Multiple countries refer to inclusion of studies for final analysis that used data from more than one country. If complete information on location from all primary studies were provided, then specific countries were listed.
†

Apps.
‡

Respondents.
AM, America; BC; AS, Austria; AU, Australia; BA, Bangladesh; BC, breast cancer; BE, Belgium; BR, Brazil; CA, Canada; China; CRC, colorectal cancer; CV, cervical cancer; DN, Denmark; FR, France; GA, gastric cancer; GC, gynecological cancer; H&N, head and neck cancer; IN, India; IR, Iran; IT, Italy; JP, Japan; NA, not applicable; NL, Netherlands; NP, not provided; OTO, otorhinolaryngology cancer; PC, pediatric cancer; PG, Portugal; SC, Scotland; SL, Slovenia or Sri Lanka; SN, Singapore; SP, Spain; TU, Turkey; TW, Taiwan; UK, United Kingdom; United States; ZA, Zambia;MT, modification of treatment; DCT, delayed and/or canceled treatment; DCS, delayed and canceled screening; RD, reduced diagnosis: RHPV, reduced uptake of HPV vaccination; TL, telemedicine; PSND, psychological needs/distress; FBD, financial burden/distress; SIA, social isolation; O, other aspects.

Table 2

Methodological rigor of included reviews.

Author	Checklist use	Methodological rigor conclusion category	GRADE
Adham et al., 2022	CEBM	Not provided	Not provided
Alkatout et al., 2021	NOS	Strong evidence	Not provided
Alom et al., 2021	NHLBI, NIH	Not provided	Not provided
Ayubi et al., 2021	Not applied	Not provided	Not provided
Azab and Azzam, 2021	Not applied	Not provided	Not provided
Bezerra et al., 2022	Not applied	Not provided	Not provided
Di Cosimo et al., 2022	CLARITY	Mixed/Intermediate	Not provided
Crosby and Sharma, 2020	Not applied	Not provided	Not provided
de Bock et al., 2022	ROBINS-I	Strong evidence	Not provided
Dhada et al., 2021	CASP, NHLBI, NIH	Mixed/Intermediate	Not provided
Donkor et al., 2021	JBI	Weak	Not provided
Fancellu et al., 2022	Not applied	Not provided	Not provided
Ferrara et al., 2022	NOS	Strong evidence	Not provided
Gadsden et al., 2022	JBI, ROBINS-I	Mixed/Intermediate	Not provided
Garg et al., 2020	Not applied	Not provided	Not provided
Gascon et al., 2022	Agree II	Mixed/Intermediate	Not provided
Hesary and Salehiniya, 2022	NOS	Mixed/Intermediate	Not provided
Hojaij et al., 2020	Not applied	Not provided	Not provided
Jammu et al., 2021	Not applied	Not provided	Not provided
Kirby et al., 2022	JBI, CHEC	Mixed/Intermediate	Not provided
Legge et al., 2022	MMAT	Strong evidence	Not provided
Lignou et al., 2022	Not applied	Not provided	Not provided
Lu et al., 2021	MARS	Mixed/Intermediate	Not provided
Majeed et al., 2022	Not applied	Not provided	Low to moderate certainty
Mayo et al., 2021	NOS	Mixed/Intermediate	Moderate to high
Mazidimoradi et al., 2021	NOS	Mixed/Intermediate	Not provided
Mazidimoradi et al., 2022	NOS	Strong evidence	Not provided
Momenimovahed et al., 2021	Not applied	Not provided	Not provided
Mostafaei et al., 2022	JBI	Mixed/Intermediate	Not provided
Moujaess et al., 2020	Not applied	Not provided	Not provided
Muls et al., 2022	MMAT	Mixed/Intermediate	Not provided
Murphy et al., 2022	JBI, CHEC	Mixed/Intermediate	Not provided
Ng and Hamilton, 2022	NOS	Mixed/Intermediate	Not provided
Nikolopoulos et al., 2022	NOS	Mixed/Intermediate	Not provided
Pacheco et al., 2021	JBI, ROBINS-I	Weak	Not provided
Pararas et al., 2022	NOS	Strong evidence	Not provided
Pascual et al., 2022	Not applied	Not provided	Not provided
Piras et al., 2022	Not applied	Not provided	Not provided
Riera et al., 2021	ROBINS-I	Mixed/Intermediate	Not provided
Rohilla et al., 2021	Not applied	Not provided	Not provided
Salehi et al., 2022	Not applied	Not provided	Not provided
Sarich et al., 2022	ROBINS-I	Weak evidence	Not provided
Sasidharanpillai and Ravishankar, 2022	NHLBI, NIH	Strong evidence	Not provided
Sun et al., 2021	Not applied	Not provided	Not provided
Tang et al., 2022	NOS	Strong evidence	Not provided
Teglia et al., 2022a	CASP	Mixed/Intermediate	Not provided
Teglia et al., 2022b	CASP	Mixed/Intermediate	Not provided
Thomson et al., 2020	ASTRO	Mixed/Intermediate	Not provided
Vigliar et al., 2020	Not applicable	Not provided	Not provided
Zapała et al., 2022	Not applied	Not provided	Not provided
Zhang et al., 2022	JBI	Mixed/Intermediate	Not provided

CEBM, Critical appraisal tool of qualitative studies from Centre of Evidence-based Medicine (CEBM), University of Oxford; ASTRO, The American Society of Radiation Oncology; CASP, https://casp-uk.net/casp-tools-checklists/; CHEC, Consensus on Health Economic Criteria: CLARITY, ‘Risk of bias instrument for cross-sectional surveys of attitudes and practices’ from the CLARITY Group at McMaster University; JBI, Joanna Briggs Institute; MARS, Mobile Apps Rating Scale; MMAT, Mixed Methods Appraisal Tool; NHLBI, NHI, National Institute of Health Checklist; NOS, Newcastle-Ottawa Quality Assessment: RBC, Risk of Bias Checklist for Prevalence Studies by Hoy et al., 2012.

Table 3

Methodological assessment of the included reviews – AMSTAR-2 evaluation (16 questions)*.

Authors, year of publication	Q1	Q2	Q3	Q4	Q5	Q6	Q7	Q8	Q9^†	Q10	Q11	Q12	Q13	Q14	Q15	Q16	Overall assessment
Adham et al., 2022	n	n	n	py	n	n	n	n	y	n	na	na	na	n	na	n	Critical low
Alkatout et al., 2021	n	py	y	py	n	n	n	py	y	n	na	na	n	n	na	y	Critical low
Alom et al., 2021	n	n	n	py	n	y	n	py	y	n	na	na	y	n	na	y	Critical low
Ayubi et al., 2021	y	n	n	py	n	n	n	y	n	n	y	n	n	n	y	y	Critical low
Azab and Azzam, 2021	n	n	n	py	y	y	n	y	py	n	y	n	n	n	y	y	Critical low
Bezerra et al., 2022	y	n	n	n	n	n	n	y	n	n	na	na	n	n	na	y	Critical low
Crosby and Sharma, 2020	n	n	n	n	n	n	n	n	n	n	na	na	na	n	na	y	Critical low
de Bock et al., 2022	y	n	y	py	y	y	n	y	y	n	y	n	n	y	n	y	Critical low
Dhada et al., 2021	n	py	n	py	n	n	n	y	y	n	na	na	n	n	na	y	Critical low
Di Cosimo et al., 2022	n	n	n	py	y	n	n	y	y	n	y	y	y	y	y	y	Critical low
Donkor et al., 2021	n	n	n	py	y	y	n	y	y	n	na	na	na	n	na	y	Critical low
Fancellu et al., 2022	y	n	n	n	n	n	n	n	n	n	na	na	n	n	n	n	Critical low
Ferrara et al., 2022	n	py	n	py	y	y	n	n	y	n	na	na	y	n	na	y	Low
Gadsden et al., 2022	y	py	n	py	y	n	n	y	y	n	na	na	y	n	na	y	Low
Garg et al., 2020	n	n	n	py	y	y	n	n	n	n	na	na	n	y	na	y	Critical low
Gascon et al., 2022	y	y	n	y	y	y	n	na	y	y	na	na	na	n	na	y	Low
Hesary and Salehiniya, 2022	n	py	n	py	n	n	n	n	y	n	na	na	n	n	na	y	Critical low
Hojaij et al., 2020	n	n	n	n	n	n	n	n	n	n	na	na	na	n	na	y	Critical low
Jammu et al., 2021	n	n	n	py	y	y	n	n	n	n	na	na	n	n	na	y	Critical low
Kirby et al., 2022	y	py	n	y	n	y	n	py	y	n	na	na	n	n	na	y	Critical low
Legge et al., 2022	y	py	y	py	y	y	n	y	y	n	na	na	n	n	na	y	Critical low
Lignou et al., 2022	y	n	n	n	y	y	n	y	n	n	na	na	n	n	na	y	Critical low
Lu et al., 2021	y	n	na	py	n	n	n	y	na	n	na	na	na	n	na	y	Critical low
Majeed et al., 2022	n	y	n	py	n	y	n	n	py	n	na	na	n	n	na	y	Critical low
Mayo et al., 2021	n	y	n	py	y	y	n	n	py	n	n	y	y	n	n	y	Critical low
Mazidimoradi et al., 2022	n	py	n	py	n	n	n	py	y	n	na	na	n	n	na	y	Critical low
Mazidimoradi et al., 2021	n	py	n	py	n	n	n	y	y	n	na	na	n	n	na	y	Critical low
Momenimovahed et al., 2021	n	n	n	py	n	n	n	n	n	n	na	na	n	n	na	y	Critical low
Mostafaei et al., 2022	n	py	n	n	n	n	y	py	y	n	na	na	n	n	na	y	Critical low
Muls et al., 2022	y	py	y	py	n	y	n	y	y	n	na	na	n	n	na	y	Critical low
Murphy et al., 2022	n	n	n	y	n	n	n	y	y	n	na	na	n	n	na	y	Critical low
Ng and Hamilton, 2022	n	py	n	py	n	n	n	py	y	n	y	n	y	y	y	y	Low
Nikolopoulos et al., 2022	n	py	n	py	n	n	n	n	y	n	na	na	n	n	na	y	Critical low
Pacheco et al., 2021	y	y	y	py	y	y	y	py	y	y	na	na	y	n	na	y	High quality
Pararas et al., 2022	n	y	n	y	y	n	n	n	y	n	n	n	n	y	y	y	Critical low
Pascual et al., 2022	y	n	y	py	y	y	n	y	n	n	na	na	n	y	na	n	Critical low
Piras et al., 2022	n	n	n	py	n	n	n	py	n	n	na	na	n	n	na	y	Critical low
Riera et al., 2021	n	py	y	py	y	y	y	y	y	y	na	na	n	y	na	y	Moderate quality
Rohilla et al., 2021	n	n	n	py	n	y	n	n	n	n	na	na	n	n	na	y	Critical low
Salehi et al., 2022	n	n	n	py	y	n	n	n	n	n	na	na	n	n	na	y	Critical low
Sarich et al., 2022	y	y	y	py	y	y	n	y	y	n	y	y	n	y	n	y	Critical low
Sasidharanpillai and Ravishankar, 2022	n	py	n	py	n	n	n	y	y	n	y	y	y	y	y	y	Low
Sun et al., 2021	n	n	n	py	n	n	n	n	n	n	na	na	na	n	na	n	Critical low
Tang et al., 2022	y	n	n	n	n	n	n	n	y	py	n	n	n	y	n	y	Critical low
Teglia et al., 2022a	y	py	y	py	y	y	n	n	y	n	n	n	n	n	y	y	Critical low
Teglia et al., 2022b	y	py	y	py	y	y	n	py	y	n	n	n	n	y	n	y	Critical low
Thomson et al., 2020	n	n	n	n	n	n	n	n	y	n	y	n	n	n	na	y	Critical low
Vigliar et al., 2020 ^†	na	na	na	na	na	na	na	na	na	na	na	na	na	na	na	na	NA
Zapała et al., 2022	n	n	n	n	n	n	n	n	n	n	na	na	n	n	na	y	Critical low
Zhang et al., 2022	y	y	y	py	n	y	n	py	y	n	y	y	y	y	y	y	Low

AMSTAR-2 overall assessment rating: high—the review provides an accurate and comprehensive summary of the results of the available studies that addresses the question of interest; moderate—the review has more than one weakness, but no critical flaws. It may provide an accurate summary of the results of the available studies; low—the review has a critical flaw and may not provide an accurate and comprehensive summary of the available studies that address the question of interest; or critically low—the review has more than one critical flaw and should not be relied on to provide an accurate and comprehensive summary of the available studies.
Q1: Did the research questions and inclusion criteria for the review include the components of PICO?
Q2: Did the report of the review contain an explicit statement that the review methods were established prior to the conduct of the review and did the report justify any significant deviations from the protocol?
Q3: Did the review authors explain their selection of the study designs for inclusion in the review?
Q4: Did the review authors use a comprehensive literature search strategy?
Q5: Did the review authors perform study selection in duplicate?
Q6: Did the review authors perform data extraction in duplicate?
Q7: Did the review authors provide a list of excluded studies and justify the exclusions?
Q8: Did the review authors describe the included studies in adequate detail?
Q9: Did the review authors use a satisfactory technique for assessing the risk of bias (RoB) in individual studies that were included in the review?
Q10: Did the review authors report on the sources of funding for the studies included in the review?
Q11: If meta-analysis was performed did the review authors use appropriate methods for statistical combination of results?
Q12: If meta-analysis was performed, did the review authors assess the potential impact of RoB in individual studies on the results of the meta-analysis or other evidence synthesis?
Q13: Did the review authors account for RoB in individual studies when interpreting/discussing the results of the review?
Q14: Did the review authors provide a satisfactory explanation for, and discussion of, any heterogeneity observed in the results of the review?
Q15: If they performed quantitative synthesis did the review authors carry out an adequate investigation of publication bias (small study bias) and discuss its likely impact on the results of the review?
Q16: Did the review authors report any potential sources of conflict of interest, including any funding they received for conducting the review?
*

The review scored yes if study used a checklist to evaluate methodological rigor, and partial yes if only GRADE assessment was provided without applying a checklist for assessing methodological rigor.
†

Individual participant meta-analysis and thus not applicable the AMSTAR evaluation.
n, no; na, not applicable; py, partially yes; y, yes.

Table 4

Summary estimates of the meta-analysis included.

Author	No. of studies	Outcome	Estimate	LCI	UCI	I²	p-heterogeniety	Metric
Ayubi et al., 2021	15	Depression	0.37	0.27	0.47	99	<0.001	Prev^†
	17	Anxiety	0.38	0.31	0.46	99	<0.001	Prev^†
	4	Anxiety	0.25	0.08	0.42	68	0.02	SMD^†

Zhang et al., 2022	28	Depression	0.325	0.263	0.392	99	<0.001	Prev^†
	34	Anxiety	0.313	0.254	0.375	99	<0.001	Prev^†
	8	PTSD	0.288	0.207	0.368	99	<0.001	Prev^†
	5	Distress	0.539	0.469	0.609	67	0.016	Prev^†
	5	Insomia	0.232	0.171	0.293	91	<0.001	Prev^†
	3	Fear of cancer progression	0.674	0.437	0.91	93	<0.001	Prev^†

Di Cosimo et al., 2022	28	Cancellation/delay of treatment	0.58	0.48	0.67	98	<0.01	Prop*^†
	14	Modification of treatment	0.65	0.53	0.75	98	<0.01	Prop*^†
	10	Delay of clinic visits	0.75	0.49	0.95	99	<0.01	Prop*^†
	14	Reduction in activity	0.58	0.47	0.68	93	<0.01	Prop*^†
	25	Use of remote consultation	0.72	0.59	0.84	99	<0.01	Prop*^†
	7	Routine use of PPE (patients)	0.81	0.75	0.95	96	<0.01	Prop*^†
	16	Routine use of PPE (workers)	0.8	0.61	0.94	99	<0.01	Prop*^†
	18	Routine screening SARA-CoV-2 swab	0.41	0.3	0.53	96	<0.01	Prop*^†

de Bock et al., 2022	5	≥T2 stage during the COVID-19 pandemic compared to the pre-pandemic control group	1.00	0.72	1.38	58	0.05	OR^‡
	4	≥T3 stage during the COVID-19 pandemic compared to the pre-pandemic control group	0.95	0.69	1.32	39	0.18	OR^‡
	5	≥N1 stage during the COVID-19 pandemic compared to the pre-pandemic control group	1.55	0.87	2.74	3	0.39	OR^‡

Mayo et al., 2021	6	Screening breast cancer	0.63	0.53	0.77	100	<0.001	IRR^‡
	5	Screening conlonc cancer	0.11	0.05	0.24	100	<0.001	IRR^‡
	3	Screening cervical cancer	0.1	0.04	0.24	100	<0.001	IRR^‡

Ng and Hamilton, 2022	3	Screening breast cancer registry-based study	0.59	0.46	0.7	100	<0.001	RR^‡
	10	Screening breast cancer non-registry-based study	0.47	0.38	0.58	100	<0.001	RR^‡
	4	Diagnosis breast cancer registry-based study	0.82	0.63	1.06	99	<0.001	RR^‡
	18	Diagnosis breast cancer non-registry-based study	0.71	0.63	0.8	92	<0.001	RR^‡

Pararas et al., 2022	5	Tis-T1 stage	1.14	0.87	1.48	41	0.15	OR^‡
	5	T2 stage	0.91	0.78	1.06	0	0.6	OR^‡
	5	T3 stage	1.18	0.82	1.7	88	<0.001	OR^‡
	6	T4 stage	1.19	0.79	1.8	80	<0.001	OR^‡
	6	N+ stage	1	0.89	1.11	0	0.54	OR^‡
	6	M+ stage	1.65	1.02	2.67	91	<0.001	OR^‡
	7	Right-sided tumors	0.88	0.51	1.52	99	<0.001	OR^‡
	7	Left-sided tumors	0.91	0.56	1.5	96	<0.001	OR^‡
	8	Rectal tumors	0.93	0.63	1.37	95	<0.001	OR^‡
	3	Emergency presantations	1.74	1.07	2.84	95	<0.001	OR^‡
	3	Complicated tumor	1.72	0.78	3.78	82	0.004	OR^‡
	3	Neoadjuvant therapy	1.22	1.09	1.37	0	0.4	OR^‡
	4	Palliative internt surgery	1.95	1.13	3.36	54	0.09	OR^‡
	6	Minimally invasive surgery	0.68	0.37	1.24	98	<0.001	OR^‡
	5	Stoma formation	0.91	0.51	1.62	94	<0.001	OR^‡
	2	Morbidity	0.92	0.55	1.55	25	0.25	OR^‡
	3	Leng of hospital stay	0.51	−0.93	1.94	79	0.008	WMD^‡
	3	Lymph node harvest	1.57	−1.99	5.13	64	0.06	WMD^‡

Sarich et al., 2022	12	Smoking prevalence	0.87	0.79	0.97	99	<0.001	PR^‡
	17	Among smokers, smoking less prevalence	0.21	0.14	0.3	99	<0.001	Prev^†
	22	Among smokers, smoking more	0.27	0.22	0.32	98	<0.001	Prev^†
	17	Among smokers, smoking unchanged	0.5	0.41	0.58	99	<0.001	Prev^†
	6	Among smokers, quit smoking	0.04	0.01	0.09	95	<0.001	Prev^†
	4	Among non-smokers, started smoking	0.02	0.01	0.03	92	<0.001	Prev^†

Sasidharanpillai and Ravishankar, 2022	7	Women screened before the COVID-19 pandemic	0.0979	0.06	0.1359	100	<0.001	Prop
	7	Women screened during the COVID-19 pandemic	0.0424	0.0277	0.0571	100	<0.001	Prop

Tang et al., 2022	10	Postoperative morbidity	0.9	0.8	1.01	26	0.22	OR^‡
	8	Postoperative mortality	1.27	0.92	1.75	0	0.57	OR^‡
	4	Converion rate	1.07	0.75	1.52	31	0.23	OR^‡
	5	Incidence of anastomotic leakage	0.71	0.07	19.22	0	0.74	OR^‡
	2	Intensive care unit demand rate	0.73	0.29	1.85	0	0.5	OR^‡
	4	R1 resections rate	0.46	0.11	1.9	0	0.48	OR^‡
	5	Mean lymph node yield	0.16	−2.26	2.59	54	0.07	MD^‡
	7	Length of hospital stay	−0.05	−2.28	2.19	98	<0.001	MD^‡

Teglia et al., 2022a	21	Breast cancer screening January–October 2020	0.467	0.378	0.378	NP	NP	PRED^‡
	21	Breast cancer screening April 2020	0.74	0.567	0.918	NP	NP	PRED^‡
	21	Breast cancer screening June–October 2020	0.13	−0.07	0.33	NP	NP	PRED^‡
	22	Colorectal cancer screening January–October 2020	0.449	0.361	0.538	NP	NP	PRED^‡
	21	Colonoscopy screening January–October 2020	0.525	0.388	0.663	NP	NP	PRED^‡
	21	Fecal occult blood test or fecal immunochemical test January–October 2020	0.378	0.258	0.499	NP	NP	PRED^‡
	21	Colorectal cancer screening April 2020	0.693	0.369	1	NP	NP	PRED^‡
	21	Colorectal cancer screening June–October 2020	0.234	0.024	0.444	NP	NP	PRED^‡
	11	Cervical cancer screening January–October 2020	0.518	0.389	0.647	NP	NP	PRED^‡
	21	Cervical cancer screening March 2020	0.788	0.583	0.993	NP	NP	PRED^‡
								PRED^‡
Teglia et al., 2022b	NP	Overall treatment January–October 2020	0.187	0.133	0.241	NP	NP	PRED^‡
	NP	Overall treatment January–February 2020	0.027	0.045	0.1	NP	NP	PRED^‡
	NP	Overall treatment March 2020	0.156	0.076	0.237	NP	NP	PRED^‡
	NP	Overall treatment April 2020	0.283	0.194	0.372	NP	NP	PRED^‡
	NP	Overall treatment May 2020	0.262	0.176	0.041	NP	NP	PRED^‡
	NP	Overall treatment June–October 2020	0.16	0.041	0.279	NP	NP	PRED^‡
	NP	Overall surgical treatment January–October 2020	0.339	0.279	0.399	NP	NP	PRED^‡
	NP	Overall surgical treatment January–February 2020	0.072	−0.093	0.238	NP	NP	PRED^‡
	NP	Overall surgical treatment March 2020	0.307	0.219	0.396	NP	NP	PRED^‡
	NP	Overall surgical treatment April 2020	0.342	0.239	0.445	NP	NP	PRED^‡
	NP	Overall surgical treatment May 2020	0.416	0.318	0.514	NP	NP	PRED^‡
	NP	Overall surgical treatment June–October 2020	0.351	0.186	0.516	NP	NP	PRED^‡
	NP	Overall medical treatment January–October 2020	0.126	0.048	0.204	NP	NP	PRED^‡
	NP	Overall medical treatment January–February 2020	0.015	−0.055	0.084	NP	NP	PRED^‡
	NP	Overall medical treatment March 2020	0.116	−0.012	0.233	NP	NP	PRED^‡
	NP	Overall medical treatment April 2020	0.248	0.09	0.407	NP	NP	PRED^‡
	NP	Overall medical treatment May 2020	0.196	0.085	0.306	NP	NP	PRED^‡
	NP	Overall medical treatment June–October 2020	0.079	−0.078	0.236	NP	NP	PRED^‡
								PRED^‡
Vigliar et al., 2020	41	Cytological samples over 4 weeks of the COVID-19 pandemic	0.453	0.001	0.98	NP	NP	PRED^‡
	41	Ratio of exfoliative to fine needle aspiration samples	0.89	0.74	1.08	95	<0.01	OR^‡
	27	Malignant diagnosis	0.0556	0.0377	0.0735	81	<0.01	RD^‡

*

Surveyed centers/operators.
†

Estimates are during pandemic.
‡

Estimates are pandemic vs. pre-pandemic.
LCI, lower confidence interval; IRR, incidence rate ratio; MD, mean difference; OR, odds ratio; PRED, percent reduction; PR, prevalence ratio; Prev, prevalence: Prop, proportion; RD, risk difference; RR, rate ratio; PPE, personal protective equipment; NP, not provided; UCI, upper confidence interval; SMD, standardized mean difference; WMD, weighted mean difference.