Using Automated Text Messages to Monitor Adverse Events Following Immunisation in General Practice

"Active postmarketing surveillance of vaccine safety using SMS technology has the capacity to complement passive reporting systems, potentially enabling more rapid identification of emerging safety signals."

This Australian study sought to assess the performance of SmartVax, a prototypic active monitoring system for adverse events following immunisation (AEFI) using short message service (SMS) text messages and clinical data extracted from commercially available medical practice management software.

In Australia and other countries, post-licensure monitoring of vaccine safety relies largely on passive surveillance. The constraints of passive AEFI reporting systems include underreporting, biased reporting, and the inability to establish rates. These limitations may result in delayed detection of potential safety signals. It was in this context that SmartVax was developed.

As reported here, the Illawarra Medical Centre (IMC) in Perth, Western Australia, administers more than 2,000 vaccinations annually and documents each of these events in the patient's electronic medical record (EMR). Between November 11 2011 and June 10 2013, SmartVax was used to send an SMS to vaccinated patients (or parents of paediatric patients) who had provided a mobile telephone number. The SMS asked patients if there were any reactions to the vaccination and requested a "Yes" or "No" reply by SMS. SMS replies were automatically written back into the SmartVax tool, linked to the patients' vaccination data, and collated in real-time. Routinely, 24 hours were allowed for receipt of a response, after which clinic staff telephoned those who indicated they had experienced a reaction, as well as those who had not responded. During the phone call, a survey was administered to ascertain the nature, duration, and severity of any reaction reported.

Of 3,281 vaccinated patients, 3,226 (98.3%) had a mobile telephone number on record and were sent an SMS. Of 2342 patients (72.6%; 95% confidence interval (CI), 70.0%-75.1%) who responded by SMS, 264 (11.3%; 95 CI, 9.9%-12.7%) reported possible AEFI. The response rate was ≥70% for both paediatric and adult patients. The SMS replies were very timely. Half the patients responded within 10 minutes of receiving the SMS, and more than 80% of responses were received within 2 hours.

"The ability of an AEFI monitoring system to detect potential safety signals early is predicated, in part, on having large numbers of patients included in the surveillance program. By developing an AEFI monitoring system that works with a widely used practice management software application, and that could likely be modified to work with others, there is potential to expand the number of participating practices to achieve a large representative sentinel population....Such a system could make a valuable contribution to assuring vaccine safety when new vaccine formulations are introduced, including any future rollout of pandemic influenza vaccines."