Abstract
OBJECTIVE: Monitoring adverse reactions is essential to confirm vaccine safety profiles. Studies using electronic tools for data collection may reach a broader audience, improving data efficiency and integrity, reducing study costs and simplifying data collection compared with nonelectronic methods. This study aimed to validate electronic versus paper diaries for reporting postimmunization reactions in Panama. METHODS: An experimental design was conducted with three groups (children, pregnant women, and older adults). Groups were divided into one subgroup using paper diary and one using electronic diary. Diary assignments were subsequently reversed in children group, which parents completed. Symptoms and reporting frequency were collected in 2020 and 2021. Information reported in paper diaries was entered into an electronic case report form and reconciled. Users' adherence, differences between reported symptom frequency and users' acceptability of diaries were evaluated. RESULTS: A total of 180 participants were included: 79 children, 21 pregnant women, 80 older adults. Children group showed greater adherence to both diaries. No significant differences were found in response times in the electronic diary between groups. More symptoms were reported in the electronic diary. The experience of using diaries, no matter which one, was similar. CONCLUSIONS: Results indicate young people adapt better to technological tools than older adults, suggesting tools should be adjusted according to the user's age. Furthermore, electronic applications for reporting postimmunization reactions offer suitable pharmacovigilance alternatives, providing real-time information, and requiring fewer staff, leading to improved health outcomes, patient compliance, and data for research and public health analysis, supporting global vaccine development.