Costeira 2021.

Study characteristics
Methods	Self‐reported data from users input to COVID Symptom Study Smartphone Application; data obtained between 7 May to 15 June 2020
Participants	Women in the UK using the Smartphone application, subgroup of n = 295,689 female app users 20 to 45 years old with BMI between 18 to 35 kg/m2
Interventions	Combined oral contraceptive use
Outcomes	Hospitalization
Notes	Users were not known to be COVID‐19 positive, but were recording COVID‐19 symptoms, so were likely to be concerned that they were positive