Table 2. ACE questionnaire domains mapped onto Read codes; childhood consequences of ACEs; wider childhood adversity; and adult consequences of ACEs; frequency counts of Read codes recorded and the NLP process
ACE domain Frequency count of Read codes per patient (% sample) Bi/trigram retrieved then sense check edited Bi/trigrams retained after concordance check Conclusion
Mapped onto ACE questionnaire
Sexual abuse1306 (0.19)9/105 bigrams15/119 trigrams retained1 trigram retained‘sexual abuse by’Insufficient to proceed with generating dummy Read code
Physical abuse279 (0.04)1/17 bigrams4/24 trigrams retained0 retainedInsufficient to proceed with generating dummy Read code
Verbal abuse76 (0.01)Insufficient data–NLP not possible
Domestic violence1017 (0.15)Insufficient data–NLP not possible
Parental separation16 (0.002)Insufficient data–NLP not possible
Mental illnessNo Read Code linked to this domain––NLP not possible
Alcohol abuse74 (0.01)0/5 bigrams0/5 trigrams retained–NLP not possible
Drug abuse83 (0.01)1/5 bigrams1/4 trigrams retained1 trigram retained‘on methadone programme’Insufficient to proceed with generating dummy Read code
Incarceration25 (0.003)Insufficient data–NLP not possible
Childhood consequences of ACEs 11 819 (1.72)224/998 bigrams412/998 trigrams retainedData accuracy poor as mixture of ACE exposures and consequences identifiedCodes insufficiently specific to the category of consequences of ACE to proceed
Wider childhood adversity
‘Inadequate childhood experience’231 (0.03)0/4 bigrams0/7 trigrams retained–NLP not possible
Problems at school621 (0.09)1/137 bigrams10/83 trigrams retained1 trigram retained‘by school psychologist’Insufficient to proceed with dummy Read code
Neglect17 (0.002)Insufficient data–NLP not possible
Adult consequences of ACEs 10 163 (1.48)86/1466 bigrams219/1468 trigrams retainedData accuracy poor despite event age method; accuracy of exposure in childhood versus adulthood, and perpetrator versus victim statusCodes insufficiently specific to the category of adult consequences of ACE to proceed

  • ACE = adverse childhood experience. NLP = natural language processing.