Table 1.

Characteristics of included studies

Characteristics	No. of studies (%)
Country
Developed	8 (80)
Developing	2 (20)
Latitude (degrees)
⩽23·5	7 (70)
>23·5	3 (30)
Setting
Household	5 (50)
Elementary school	2 (20)
University residential hall	2 (20)
Office	1 (10)
Transmission mode
Primary	6 (60)
Secondary	4 (40)
Interventions evaluated*
Hand sanitizer and facemask	4 (31)
Hand sanitizer, non-antibacterial soap and education	3 (23)
Hand sanitizer	2 (15)
Non-antibacterial soap and education	2 (15)
Non-antibacterial soap, education and facemask	1 (8)
Hand sanitizer, non-antibacterial soap, education and facemask	1 (8)
Outcome assessed*
Laboratory-confirmed influenza	9 (50)
Influenza-like-illness	9 (50)

^*Some studies assess more than one intervention and outcome.