Risk of thromboembolism in patients with COVID-19 who are using hormonal contraception

BACKGROUND

The novel coronavirus disease (COVID-19) has led to significant mortality and morbidity, including a high incidence of related thrombotic events. There has been concern regarding hormonal contraception use during the COVID-19 pandemic, as this is an independent risk factor for thrombosis, particularly with estrogen-containing formulations. However, higher estrogen levels may be protective against severe COVID-19 disease. Evidence for risks of hormonal contraception use during the COVID-19 pandemic is sparse. We conducted a living systematic review that will be updated as new data emerge on the risk of thromboembolism with hormonal contraception use in patients with COVID-19.

OBJECTIVES

To determine if use of hormonal contraception increases risk of venous and arterial thromboembolism in women with COVID-19. To determine if use of hormonal contraception increases other markers of COVID-19 severity including hospitalization in the intensive care unit, acute respiratory distress syndrome, intubation, and mortality. A secondary objective is to maintain the currency of the evidence, using a living systematic review approach.

SEARCH METHODS

⁠⁠⁠⁠⁠⁠We searched CENTRAL, MEDLINE, Embase, CINAHL, Global Index Medicus, Global Health, and Scopus from inception on March 2023, and monitored the literature monthly. We updated the search strategies with new terms and added the database Global Index Medicus in lieu of LILACS.

SELECTION CRITERIA

We included all published and ongoing studies of patients with COVID-19 comparing outcomes of those on hormonal contraception versus those not on hormonal contraception. This included case series and non-randomized studies of interventions (NRSI).

DATA COLLECTION AND ANALYSIS

One review author extracted study data and this was checked by a second author. Two authors individually assessed risk of bias for the comparative studies using the ROBINS-I tool and a third helped reconcile differences. For the living systematic review, we will publish updates to our synthesis every six months. In the event that we identify a study with a more rigorous study design than the current included evidence prior to the planned six-month update, we will expedite the synthesis publication.

MAIN RESULTS

We included three comparative NRSIs with 314,704 participants total and two case series describing 13 patients. The three NRSIs had serious to critical risk of bias in several domains and low study quality. Only one NRSI ascertained current use of contraceptives based on patient report; the other two used diagnostic codes within medical records to assess hormonal contraception use, but did not confirm current use nor indication for use. None of the NRSIs included thromboembolism as an outcome. Studies were not similar enough in terms of their outcomes, interventions, and study populations to combine with meta-analyses. We therefore narratively synthesized all included studies. Based on results from one NRSI, there may be little to no effect of combined hormonal contraception use on odds of mortality for COVID-19 positive patients (OR 1.00, 95% CI 0.41 to 2.40; 1 study, 18,892 participants; very low-certainty evidence). Two NRSIs examined hospitalization rates for hormonal contraception users versus non-users. Based on results from one NRSI, the odds of hospitalization for COVID-19 positive combined hormonal contraception users may be slightly decreased compared with non-users for patients with BMI under 35 kg/m2 (OR 0.79, 95% CI 0.64 to 0.97; 1 study, 295,689 participants; very low-certainty evidence). According to results of the other NRSI assessing use of any type of hormonal contraception, there may be little to no effect on hospitalization rates for COVID-19 positive individuals (OR 0.99, 95% CI 0.68 to 1.44; 1 study, 123 participants; very low-certainty evidence). We included two case series because no comparative studies directly assessed thromboembolism as an outcome. In a case series of six pediatric COVID-19 positive patients with pulmonary embolism, one (older than 15 years of age) was using combined hormonal contraception. In a second case series of seven COVID-19 positive patients with cerebral venous thrombosis, one was using oral contraceptives. One comparative study and one case series reported on intubation rates, but the evidence for both is very uncertain. In the comparative study of 123 COVID-19 positive patients (N = 44 using hormonal contraception and N = 79 not using hormonal contraception), no patients in either group required intubation. In the case series of seven individuals with cerebral venous thromboembolism, one oral contraceptive user and one non-user required intubation.

AUTHORS' CONCLUSIONS

There are no comparative studies assessing risk of thromboembolism in COVID-19 patients who use hormonal contraception, which was the primary objective of this review. Very little evidence exists examining the risk of increased COVID-19 disease severity for combined hormonal contraception users compared to non-users of hormonal contraception, and the evidence that does exist is of very low certainty. The odds of hospitalization for COVID-19 positive users of combined hormonal contraceptives may be slightly decreased compared with those of hormonal contraceptive non-users, but the evidence is very uncertain as this is based on one study restricted to patients with BMI under 35 kg/m2. There may be little to no effect of combined hormonal contraception use on odds of intubation or mortality among COVID-19 positive patients, and little to no effect of using any type of hormonal contraception on odds of hospitalization and intubation for COVID-19 patients. We noted no large effect for risk of increased COVID-19 disease severity among hormonal contraception users. We specifically noted gaps in pertinent data collection regarding hormonal contraception use such as formulation, hormone doses, and duration or timing of contraceptive use. Differing estrogens may have different thrombogenic potential given differing potency, so it would be important to know if a formulation contained, for example, ethinyl estradiol versus estradiol valerate. Additionally, we downgraded several studies for risk of bias because information on the timing of contraceptive use relative to COVID-19 infection and method adherence were not ascertained. No studies reported indication for hormonal contraceptive use, which is important as individuals who use hormonal management for medical conditions like heavy menstrual bleeding might have different risk profiles compared to individuals using hormones for contraception. Future studies should focus on including pertinent confounders like age, obesity, history of prior venous thromboembolism, risk factors for venous thromboembolism, and recent pregnancy.

Harms of off-label erythropoiesis-stimulating agents for critically ill people

BACKGROUND

Anaemia is a common problem experienced by critically-ill people. Treatment with erythropoiesis-stimulating agents (ESAs) has been used as a pharmacologic strategy when the blunted response of endogenous erythropoietin has been reported in critically-ill people. The use of ESAs becomes more important where adverse clinical outcomes of transfusing blood products is a limitation. However, this indication for ESAs is not licensed by regulatory authorities and is called off-label use. Recent studies concern the harm of ESAs in a critical care setting.

OBJECTIVES

To focus on harms in assessing the effects of erythropoiesis-stimulating agents (ESAs), alone or in combination, compared with placebo, no treatment or a different active treatment regimen when administered off-label to critically-ill people.

SEARCH METHODS

We conducted a systematic search of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycINFO via OvidSP, CINAHL, all evidence-based medicine (EBM) reviews including IPA and SCI-Expanded, Conference Proceedings Citation Index- Science, BIOSIS Previews and TOXLINE up to February 2017. We also searched trials registries, checked reference lists of relevant studies and tracked their citations by using SciVerse Scopus.

SELECTION CRITERIA

We considered randomized controlled trials (RCTs) and controlled observational studies, which compared scheduled systemic administration of ESAs versus other effective interventions, placebo or no treatment in critically-ill people.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened and evaluated the eligibility of retrieved records, extracted data and assessed the risks of bias and quality of the included studies. We resolved differences in opinion by consensus or by involving a third review author. We assessed the evidence using GRADE and created a 'Summary of findings' table. We used fixed-effect or random-effects models, depending on the heterogeneity between studies. We fitted three-level hierarchical Bayesian models to calculate overall treatment effect estimates.

MAIN RESULTS

Of the 27,865 records identified, 39 clinical trials and 14 observational studies, including a total of 945,240 participants, were eligible for inclusion. Five studies are awaiting classification. Overall, we found 114 adverse events in 33 studies (30 RCTs and three observational studies), and mortality was reported in 41 studies (32 RCTs and nine observational studies). Most studies were at low to moderate risk of bias for harms outcomes. However, overall harm assessment and reporting were of moderate to low quality in the RCTs, and of low quality in the observational studies. We downgraded the GRADE quality of evidence for venous thromboembolism and mortality to very low and low, respectively, because of risk of bias, high inconsistency, imprecision and limitations of study design.It is unclear whether there is an increase in the risk of any adverse events (Bayesian risk ratio (RR) 1.05, 95% confidence interval (CI) 0.93 to 1.21; 3099 participants; 9 studies; low-quality evidence) or venous thromboembolism (Bayesian RR 1.04, 95% CI 0.70 to 1.41; 18,917 participants; 18 studies; very low-quality evidence).There was a decreased risk of mortality with off-label use of ESAs in critically-ill people (Bayesian RR 0.76, 95% CI 0.61 to 0.92; 930,470 participants; 34 studies; low-quality evidence).

AUTHORS' CONCLUSIONS

Low quality of evidence suggests that off-label use of ESAs may reduce mortality in a critical care setting. There was a lack of high-quality evidence about the harm of ESAs in critically-ill people. The information for biosimilar ESAs is less conclusive. Most studies neither evaluated ESAs' harm as a primary outcome nor predefined adverse events. Any further studies of ESA should address the quality of evaluating, recording and reporting of adverse events.