Patient Portal Flu Vaccine Reminders (5)

This trial is taking place in Los Angeles, CA at clinics within the UCLA Health System. The study design is a 2x2 nested factorial design. Patients will be randomized into 1) receiving text based reminder messages with direct scheduling link, 2) portal-based reminder messages with direct scheduling link, or 3) the control group. Patients randomized to the intervention arms will receive reminders if they are due for influenza vaccine. Nested within the portal reminder arm, we will have two additional components for which patients will be randomized separately: 1. A pre-commitment prompt, asking patients which time (September, October, November or December) and which place (UCLA, pharmacy, workplace or school, or other) they plan to get their Influenza vaccine with tailored monthly messages based on responses (pre-commitment message with tailored recall messages with direct scheduling vs. standard portal reminders with direct scheduling). 2. A pre-appointment reminder encouraging patients to ask for their influenza vaccine at their upcoming appointment (pre-appointment reminder encouraging influenza vaccination vs. standard pre-appointment reminder not mentioning influenza vaccination) Nested within the text message reminder arm, we will have one additional component for which patients will be randomized separately: 1\) A pre-appointment reminder encouraging patients to ask for their influenza vaccine at their upcoming appointment (pre-appointment reminder encouraging influenza vaccination vs. standard pre-appointment reminder not mentioning influenza vaccination) Despite the Advisory Committee on Immunization Practices (ACIP) recommendation in 2010 that all people above 6 months of age should receive an annual flu vaccine, vaccination rates remain low: at 6m-4.9 yrs. (70%), 5-17.9 yrs. (56%), 18-64.9 yrs. (38%), and \>65 yrs. (63%). The investigators will assess the effectiveness of MyChart R/R messages and text R/R messages as compared to the standard of care