title: Predicting Non-Adherence with Outpatient Colonoscopy Using a Novel Electronic Tool that Measures Prior Non-Adherence.
abstract: BACKGROUND
  Accurately predicting the risk of no-show for a scheduled colonoscopy can help target interventions to improve compliance with colonoscopy, and thereby reduce the disease burden of colorectal cancer and enhance the utilization of resources within endoscopy units.
  
  
  OBJECTIVE
  We aimed to utilize information available in an electronic medical record (EMR) and endoscopy scheduling system to create a predictive model for no-show risk, and to simultaneously evaluate the role for natural language processing (NLP) in developing such a model.
  
  
  METHODS
  This was a retrospective observational study using discovery and validation phases to design a colonoscopy non-adherence prediction model. An NLP-derived variable called the Non-Adherence Ratio ("NAR") was developed, validated, and included in the model.
  
  
  METHODS
  Patients scheduled for outpatient colonoscopy at an Academic Medical Center (AMC) that is part of a multi-hospital health system, 2009 to 2011, were included in the study.
  
  
  METHODS
  Odds ratios for non-adherence were calculated for all variables in the discovery cohort, and an Area Under the Receiver Operating Curve (AUC) was calculated for the final non-adherence prediction model.
  
  
  RESULTS
  The non-adherence model included six variables: 1) gender; 2) history of psychiatric illness, 3) NAR; 4) wait time in months; 5) number of prior missed endoscopies; and 6) education level. The model achieved discrimination in the validation cohort (AUC= =70.2 %). At a threshold non-adherence score of 0.46, the model's sensitivity and specificity were 33 % and 92 %, respectively. Removing the NAR from the model significantly reduced its predictive power (AUC = 64.3 %, difference = 5.9 %, p < 0.001).
  
  
  CONCLUSIONS
  A six-variable model using readily available clinical and demographic information demonstrated accuracy for predicting colonoscopy non-adherence. The NAR, a novel variable developed using NLP technology, significantly strengthened this model's predictive power.
authors.affiliation: Department of Internal Medicine, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Blumenthal
authors.forename: Gaurav
authors.initials: G
authors.lastname: Singal
authors.forename: Shikha S
authors.initials: SS
authors.lastname: Mangla
authors.forename: Eric A
authors.initials: EA
authors.lastname: Macklin
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Chung
mesh_terms: D003113:Colonoscopy / Q000523:psychology*; D057286:Electronic Health Records; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D009323:Natural Language Processing; D010349:Patient Compliance; D012189:Retrospective Studies