Summary of findings 1. Summary of findings table ‐ Combined hormonal contraception (estrogen plus progestin) compared to no contraception for COVID‐19 positive patients.

Combined hormonal contraception (estrogen plus progestin) compared to no contraception for COVID‐19 positive patients
Patient or population: COVID‐19 positive patients Setting: COVID‐19 positive patients in tertiary care setting Intervention: combined hormonal contraception Comparison: no hormonal contraception
Outcomes	Anticipated absolute effects* (95% CI)		Relative effect (95% CI)	№ of participants (studies)	Certainty of the evidence (GRADE)	Comments
	Risk with no hormonal contraception	Risk with combined hormonal contraception
Mortality	5 per 1000	5 per 1000 (2 to 11)	OR 1.00 (0.41 to 2.40)	18892 (1 observational study)	⊕⊝⊝⊝ Very lowa,b,c
Hospitalization	7 per 1000d	5 per 1000 (4 to 6)d	OR 0.79 (0.64 to 0.97)	295689 (1 observational study)	⊕⊝⊝⊝ Very lowc,e,f	Combined hormonal contraception may reduce hospitalization slightly. COVID‐19 positivity not confirmed through testing; women were using a mobile phone application to track COVID‐19 symptoms. Restricted to patients with BMI < 35 kg/m2.
Venous thromboembolism	1 of 6 pediatric COVID‐19 patients with pulmonary embolism had reportedly been using combined hormonal contraception. 1 of 7 reproductive‐aged female COVID‐19 patients with cerebral venous thromboembolism was using "oral contraceptive pills." This patient also had positive anti‐phospholipid antibodies.			13 (2 observational studies)	⊕⊝⊝⊝ Very lowg,h	2 case series were included with 13 total patients, describing venous thromboembolism in COVID‐19 patients. Neither case study ascertained active use of hormonal contraception at time of the outcome. i
Intubation	1 of 6 people who were not using hormonal contraception required intubation compared to 1 of 1 person reportedly using oral contraceptive pills.			7 (1 observational study)	⊕⊝⊝⊝ Very lowg,i	Case series of 7 reproductive‐aged women, all of whom were COVID‐19 positive and developed cerebral venous thromboembolism.
Arterial thromboembolism ‐ not measured	‐	‐	‐	‐	‐
Acute respiratory distress syndrome ‐ not measured	‐	‐	‐	‐	‐
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; OR: odds ratio
GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.
See interactive version of this table: https://gdt.gradepro.org/presentations/#/isof/isof_question_revman_web_432099564019182608.

^a Downgraded for serious risk of bias given no ascertainment of combined hormonal contraception exposure and no information on variables used for propensity score matching, increasing risk of residual confounding.
^b Downgraded for indirectness given no ascertainment of combined hormonal contraception use during time of outcome.
^c Downgraded for imprecision given results reported in only 1 study.
^d Overall 1889 of 295,689 total patients were hospitalized for an absolute risk of 6.4 per 1000 total. Hospitalizations were not reported separately for those using combined hormonal contraception (n = 64,253) versus those not using contraception (n = 231,436). Anticipated absolute effects were estimated by applying the adjusted relative effect estimate to determine expected number of intervention and control patients who were hospitalized. 
^e Downgraded for serious risk of bias due to risk of selection bias and all data are self‐reported by users.
^f Downgraded for indirectness as users of the application were not confirmed to be COVID‐19 positive, but were tracking symptoms given concern for possible COVID‐19 positivity. 
^g Downgraded 2 levels for risk of bias as case series are likely to be subject to significant bias.
^h Downgraded for imprecision for small sample sizes.
ⁱ Downgraded 2 levels for imprecision given small sample size and results reported in only 1 study.