Identification of Adverse Drug Events from Free Text Electronic Patient Records and Information in a Large Mental Health Case Register.
OBJECTIVE
Electronic healthcare records (EHRs) are a rich source of information, with huge potential for secondary research use. The aim of this study was to develop an application to identify instances of Adverse Drug Events (ADEs) from free text psychiatric EHRs.


METHODS
We used the GATE Natural Language Processing (NLP) software to mine instances of ADEs from free text content within the Clinical Record Interactive Search (CRIS) system, a de-identified psychiatric case register developed at the South London and Maudsley NHS Foundation Trust, UK. The tool was built around a set of four movement disorders (extrapyramidal side effects [EPSEs]) related to antipsychotic therapy and rules were then generalised such that the tool could be applied to additional ADEs. We report the frequencies of recorded EPSEs in patients diagnosed with a Severe Mental Illness (SMI) and then report performance in identifying eight other unrelated ADEs.


RESULTS
The tool identified EPSEs with >0.85 precision and >0.86 recall during testing. Akathisia was found to be the most prevalent EPSE overall and occurred in the Asian ethnic group with a frequency of 8.13%. The tool performed well when applied to most of the non-EPSEs but least well when applied to rare conditions such as myocarditis, a condition that appears frequently in the text as a side effect warning to patients.


CONCLUSIONS
The developed tool allows us to accurately identify instances of a potential ADE from psychiatric EHRs. As such, we were able to study the prevalence of ADEs within subgroups of patients stratified by SMI diagnosis, gender, age and ethnicity. In addition we demonstrated the generalisability of the application to other ADE types by producing a high precision rate on a non-EPSE related set of ADE containing documents.


BACKGROUND
The application can be found at http://git.brc.iop.kcl.ac.uk/rmallah/dystoniaml.
MRC Social, Genetic & Developmental Psychiatry Centre (SGDP), King's College London, London, United Kingdom.
Ehtesham
E
Iqbal
Pharmacy Department, South London and Maudsley NHS Foundation Trust, London, United Kingdom.
Robbie
R
Mallah
Department of Health Service & Population Research, Institute of Psychiatry, King's College London, London, United Kingdom; NIHR Biomedical Research Centre for Mental Health, South London and Maudsley NHS Foundation, London, United Kingdom; Biomedical Research Unit for Dementia, South London and Maudsley NHS Foundation, London, United Kingdom.
Richard George
RG
Jackson
Department of Health Service & Population Research, Institute of Psychiatry, King's College London, London, United Kingdom; NIHR Biomedical Research Centre for Mental Health, South London and Maudsley NHS Foundation, London, United Kingdom; Biomedical Research Unit for Dementia, South London and Maudsley NHS Foundation, London, United Kingdom.
Michael
M
Ball
MRC Social, Genetic & Developmental Psychiatry Centre (SGDP), King's College London, London, United Kingdom.
Zina M
ZM
Ibrahim
NIHR Biomedical Research Centre for Mental Health, South London and Maudsley NHS Foundation, London, United Kingdom; Biomedical Research Unit for Dementia, South London and Maudsley NHS Foundation, London, United Kingdom.
Matthew
M
Broadbent
Pharmacy Department, South London and Maudsley NHS Foundation Trust, London, United Kingdom.
Olubanke
O
Dzahini
Department of Health Service & Population Research, Institute of Psychiatry, King's College London, London, United Kingdom; NIHR Biomedical Research Centre for Mental Health, South London and Maudsley NHS Foundation, London, United Kingdom; Biomedical Research Unit for Dementia, South London and Maudsley NHS Foundation, London, United Kingdom.
Robert
R
Stewart
MRC Social, Genetic & Developmental Psychiatry Centre (SGDP), King's College London, London, United Kingdom.
Caroline
C
Johnston
MRC Social, Genetic & Developmental Psychiatry Centre (SGDP), King's College London, London, United Kingdom; NIHR Biomedical Research Centre for Mental Health, South London and Maudsley NHS Foundation, London, United Kingdom; Biomedical Research Unit for Dementia, South London and Maudsley NHS Foundation, London, United Kingdom.
Richard J B
RJ
Dobson
D014150:Antipsychotic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D057225:Data Mining / Q000379:methods; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology*; D057286:Electronic Health Records; D006801:Humans; D001523:Mental Disorders / Q000188:drug therapy; D012042:Registries; D012984:Software
D014150:Antipsychotic Agents