Background
We sought to use data captured in the electronic health record (EHR) to develop and validate a prediction rule for virologic failure in patients being treated for HIV infection.
Methods
We used EHRs at two Boston tertiary care hospitals, Massachusetts General Hospital and Brigham and Women's Hospital, to identify HIV-infected patients who were virologically suppressed (HIV RNA ≤400 copies/mL) on antiretroviral therapy between 1/1/05 and 12/31/06. We used a multivariable logistic model with data from Massachusetts General Hospital to derive a one-year virologic failure prediction rule. The model was validated using data from the Brigham and Women's Hospital. We then simplified the scoring scheme to develop a clinical prediction rule.
Results
The one-year virologic failure prediction model, using data from 712 Massachusetts General Hospital patients, demonstrated good discrimination (c-statistic 0.78) and calibration (χ2 =6.6, p =0.58). The validation model, based on 362 Brigham and Women's Hospital patients, also showed good discrimination (c-statistic 0.79) and calibration (χ2 =1.9, p =0.93). The clinical prediction rule included seven predictors, Sub-optimal Adherence, CD4 count <100/μL, Drug and/or Alcohol Abuse, Heavily ART Experienced, Missed ≥1Appointment, Prior Virologic Failure, and Suppressed ≤12 months, and appropriately stratified patients in the validation dataset into low, medium and high risk groups, with one-year virologic failure rates of 3.0%, 13.0% and 28.6%.
Conclusions
A risk score based on seven variables available in the EHR predicts HIV virologic failure at one year and could be used for targeted interventions to improve outcomes in HIV disease.