Table 1

Summary of findings on the risk of mortality, hospitalisation, venous thromboembolism, and intubation among COVID-19 patients in tertiary care settings using combined hormonal contraception compared with those using no form of hormonal contraception

Outcomes*Anticipated absolute effects† (95% CI)Relative effect
(95% CI)
Number of participants
Certainty of the evidence
Risk with no hormonal contraceptionRisk with combined hormonal contraception
Mortality5 per 10005 per 1000
(2 to 11)
OR 1.00
(0.41 to 2.40)
18 892
(1 observational study)
Very lowद
Hospitalisation7 per 1000d5 per 1000
(4 to 6)**
OR 0.79
(0.64 to 0.97)
295 689
(1 observational study)
Very low¶††‡‡
CHC use may reduce hospitalisation 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 thromboembolism1 of 6 paediatric 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 antibodies13
(2 observational studies)
Very low§§¶¶
2 case series were included with 13 total patients, describing VTE in COVID-19 patients. Neither case study ascertained active use of hormonal contraception at time of the outcomei
Intubation1 of 6 people who were not using hormonal contraception required intubation compared with 1 of 1 person reportedly using oral contraceptive pills7
(1 observational study)
Very low§§***
Case series of 7 reproductive-aged women, all of whom were COVID-19-positive and developed cerebral VTE
  • 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.

  • *The outcomes of arterial thromboembolism and ARDS were not measured and are not included in this table.

  • †The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

  • ‡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.

  • §Downgraded for indirectness given no ascertainment of combined hormonal contraception use during time of outcome.

  • ¶Downgraded for imprecision given results reported in only 1 study.

  • **Overall 1889 of 295 689 total patients were hospitalised for an absolute risk of 6.4 per 1000 total. Hospitalisations were not reported separately for those using combined hormonal contraception (n=64 253) vs those not using contraception (n=231 436). Anticipated absolute effects were estimated by applying the adjusted relative effect estimate to determine the expected number of intervention and control patients who were hospitalised.

  • ††Downgraded for serious risk of bias due to risk of selection bias and all data are self-reported by users.

  • ‡‡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.

  • §§Downgraded 2 levels for risk of bias as case series are likely to be subject to significant bias.

  • ¶¶Downgraded for imprecision for small sample sizes.

  • ***Downgraded 2 levels for imprecision given small sample size and results reported in only 1 study.

  • ARDS, acute respiratory distress syndrome; BMI, body mass index; CHC, combined hormonal contraception; VTE, venous thromboembolism.