Social determinants of health (SDoH) have an important impact on patient outcomes but are incompletely collected from the electronic health records (EHR). This study researched the ability of large language models to extract SDoH from free text in EHRs, where they are most commonly documented, and explored the role of synthetic clinical text for improving the extraction of these scarcely documented, yet extremely valuable, clinical data. 800 patient notes were annotated for SDoH categories, and several transformer-based models were evaluated. The study also experimented with synthetic data generation and assessed for algorithmic bias. Our best-performing models were fine-tuned Flan-T5 XL (macro-F1 0.71) for any SDoH, and Flan-T5 XXL (macro-F1 0.70). The benefit of augmenting fine-tuning with synthetic data varied across model architecture and size, with smaller Flan-T5 models (base and large) showing the greatest improvements in performance (delta F1 +0.12 to +0.23). Model performance was similar on the in-hospital system dataset but worse on the MIMIC-III dataset. Our best-performing fine-tuned models outperformed zero- and few-shot performance of ChatGPT-family models for both tasks. These fine-tuned models were less likely than ChatGPT to change their prediction when race/ethnicity and gender descriptors were added to the text, suggesting less algorithmic bias (p<0.05). At the patient-level, our models identified 93.8% of patients with adverse SDoH, while ICD-10 codes captured 2.0%. Our method can effectively extracted SDoH information from clinic notes, performing better compare to GPT zero- and few-shot settings. These models could enhance real-world evidence on SDoH and aid in identifying patients needing social support.

本研究使用大型语言模型从电子健康记录中提取社会健康决定因素（SDoH），并研究了合成临床文本对提取这些临床数据的改进作用。最佳模型是经过微调的Flan-T5 XL（宏F1值为0.71）任何SDoH和Flan-T5 XXL（宏F1值为0.70）。这些模型优于ChatGPT系列模型在任务中的零样本和少样本性能，并且对种族/民族和性别描述词的预测不太可能改变，表明较少的算法偏见（p<0.05）。在患者层面上，我们的模型识别出93.8%存在不良SDoH的患者，而ICD-10代码只能覆盖2.0%。我们的方法能有效地从临床记录中提取SDoH信息，相对于GPT的零样本和少样本设置更加优秀。这些模型可以增强关于SDoH的现实世界证据，并帮助识别需要社会支持的患者。

利用大型语言模型识别电子健康档案中的社会决定因素