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

Summary 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 more intensive treatment.