Use of large language models and synthetic social media to optimize and validate assessment of epidemiological characteristics in social media posts about outbreaks: Infodemiology Study (Preprint)

BACKGROUND Use of online search and social media can help identify epidemics, potentially earlier than clinical methods or even potentially identifying otherwise unreported outbreaks. Monitoring for eye-related epidemics can facilitate early public health intervention to reduce transmission and ocular comorbidities associated with outbreaks. However, use of social media for such monitoring is hindered by costs of laborious manual content review. To address this limitation, we have shown utility of large language models (LLMs) to assess probabilities of an outbreak from social media posts. Knowing the probability alone though may not be as informative to public health actions as also knowing more epidemiological characteristics about them, for example knowing the outbreak type, size or which ones the most severe. OBJECTIVE We assessed if and how well LLMs can classify essential epidemiological features from individual social media posts beyond outbreak probability, including outbreak type, size, severity, etiology and location as well as other health conditions. We employed a validation framework comprising synthetic, Twitter/X and forum posts, comparing an LLMs classification to other independent LLM models and to human experts. METHODS To develop effective prompts and test the capability of multiple LLMs, synthetic social media posts were generated. These synthetic posts were embedded with specific pre-classified epidemiological features to simulate various outbreak and control scenarios. To gauge the LLM’s practical utility in real-world epidemiological surveillance, top performing LLM inter-model comparisons were made using Twitter/X and forum posts. Finally, human graders also classified a subset of posts and their classifications were compared to a leading LLM for validation. Comparisons entailed correlation, or sensitivity and specificity statistics. RESULTS Seven LLMs assessed for effectively classifying epidemiological data from diverse social media posts. Notably, GPT-4 and Mixtral 8x22b exhibited high performance in predicting outbreak characteristics like probability, size, and type. Lower performing LLMs were successful for some classifications but not others. Despite strong correlations in comparative validations and known values, discrepancies were noted in a few categories of human assessments. However, overall, the models demonstrated a reliable capacity for nuanced epidemiological analysis across various data sources. CONCLUSIONS This investigation into the potential of LLMs for public health infoveillance suggests effectiveness in classifying key epidemiological characteristics from social media content about conjunctivitis outbreaks. Future studies may suggest that while LLMs have potential to support public health monitoring, their optimal role may be to act as a first line of documentation, assessment and classification of potential outbreaks, alerting public health organizations for follow-up of LLM-detected and classified small early outbreaks with a focus on the most severe ones. CLINICALTRIAL n/a