Mask up! Testing strategies to increase mask usage in Kenya*

Abstract

Background: COVID-19 continues to pose a major threat to countries around the world, and non-pharmaceutical interventions such as social distancing and face coverings remain important to reduce transmission, especially in settings with low vaccination rates. Despite a nationwide mask mandate in Kenya during the pandemic, proper masking remained low in Siaya County. We conducted a pilot study with the Siaya County Ministry of Health to improve mask adoption within Ugunja subcounty, and present initial findings on mask usage effects. Methods: The study took place across 72 villages in Ugunja subcounty, which were randomly assigned to receive: (i) free mask and education on mask usage; (ii) only education on mask usage; or (iii) no mask or education by community health workers. A role model intervention was also cross-randomized across half of the villages, along with SMS messages reinforcing a variety of messages around masking. The intervention was administered in January 2021. Data collection was done via phone survey and direct observation of mask usage. Findings: Preliminary analysis of the pilot study suggests providing free face masks may improve compliance, particularly in settings with higher COVID-19 risks. Two weeks to three months after the intervention, the free mask and education arm increased directly-observed correct mask usage by 3.1 percentage points (95% confidence interval 1.9, 6.0) on a control mean of 6.8 percent. Some treatment arms also improved COVID-19 knowledge and mask attitudes. Interpretation: Interventions designed to increase adoption of health measures can be successful, but behavioral change is challenging and may require frequent reinforcement.