JMIR Publications

ABSTRACT

Background:

Text- and internet-based self-reporting systems can supplement existing vaccine safety surveillance systems, but real-world participation patterns have not been assessed at scale.

Objective:

This study aimed to describe the participation rates of a new text- and internet-based self-reporting system called the Kaiser Permanente Side Effect Monitor (KPSEM) within a large integrated healthcare system.

Methods:

We conducted a prospective cohort study of Kaiser Permanente Southern California (KPSC) patients receiving a COVID-19 vaccination from April 23, 2021, through July 31, 2023. Patients received invitations via flyer, text message, email, or patient healthcare portals. After consenting, patients received regular surveys to assess adverse events up to five weeks after each dose. Linkage with medical records provided demographic and clinical data. In the current study, we describe KPSEM participation rates, defined as providing consent and completing at least one survey within 35 days of COVID-19 vaccination.

Results:

Approximately 8% (N= 783,602/2,091,975) of all vaccinated patients provided consent and completed at least one survey within 35 days. The lowest participation rates were observed for parents of children aged 12–17 years (N= 1,349/152,928; 0.9% participation rate), and the highest participation was observed among older adults aged 61–70 years (N= 39,844/329,487; 12.1%). Persons of Non-Hispanic White race/ethnicity were at least twice as likely to participate compared with other races and ethnicities (13.1% vs. 3.9-7.5%, respectively; p<.0001). Additionally, patients residing in areas with a higher neighborhood deprivation index were less likely to participate (5.1% [N=16,503/323,122] vs. 10.8% [N= 38,084/352,939] in the highest vs. lowest deprivation quintiles, respectively; p<0.0001).Invitations by text message and the individual’s Kaiser Permanente healthcare portal account were associated with the highest participation rates (19.2% [N= 70.248/366,377] and 10.5% [N=96,169/914,793], respectively), followed by email (N= 19,464/396,912; 4.9%) and then QR codes on flyers (N=25,882/2,091,975; 1.2%). Text-based surveys demonstrated the highest sustained daily response rates compared with internet-based surveys.

Conclusions:

This real-world prospective study demonstrated that a novel digital vaccine safety self-reporting system implemented through an integrated healthcare system can achieve high participation rates. Linkage with participants’ EHR is another unique benefit of this surveillance system. We also identified lower participation among selected vulnerable populations, which may have implications when interpreting data collected from similar digital systems. Clinical Trial: N/A