  Over the recent years, the emergence of large language models (LLMs) has
given rise to a proliferation of domain-specific models that are intended to
reflect the particularities of linguistic context and content as a correlate of
the originating domain. This paper details the conception, design, training and
evaluation of DAEDRA, a LLM designed to detect regulatory-relevant outcomes
(mortality, ER attendance and hospitalisation) in adverse event reports
elicited through passive reporting (PR). While PR is a highly cost-efficient
way of eliciting information from a wide and diverse audience -- typically
including not only physicians and healthcare providers but also patients,
family members and other lay stakeholders --, this diversity makes PR corpora
difficult to analyse. Generic language models may not capture the complex
clinical dimensions while specific clinical or biomedical models may not
perform well on lay reports. To evaluate the utility of a subdomain-specific
language model, an adaptive training approach was adapted, wherein base
language model candidates were evaluated on a subset of the corpus, and the
best performer was trained on the entire corpus. This yielded a small but
significant improvement in $F_1$ (+1%), precision (+2.5%) and recall (+3.8%),
at a relatively low training cost and a single-day training time.
Subdomain-specific LLMs continue to be viable options for better results when
analysing highly specialised corpora.
