Predicting virologic failure in an HIV clinic.
BACKGROUND
We sought to use data captured in the electronic health record (EHR) to develop and validate a prediction rule for virologic failure among patients being treated for infection with human immunodeficiency virus (HIV).


METHODS
We used EHRs at 2 Boston tertiary care hospitals, Massachusetts General Hospital and Brigham and Women's Hospital, to identify HIV-infected patients who were virologically suppressed (HIV RNA level < or = 400 copies/mL) on antiretroviral therapy (ART) during the period from 1 January 2005 through 31 December 2006. We used a multivariable logistic model with data from Massachusetts General Hospital to derive a 1-year virologic failure prediction rule. The model was validated using data from Brigham and Women's Hospital.We then simplified the scoring scheme to develop a clinical prediction rule.


RESULTS
The 1-year virologic failure prediction model, using data from 712 patients from Massachusetts General Hospital, demonstrated good discrimination (C statistic, 0.78) and calibration (chi(2)= 6.6; P= .58). The validation model, based on 362 patients from Brigham and Women's Hospital, also showed good discrimination (C statistic, 0.79) and calibration (chi(2)= 1.9; P= .93). The clinical prediction rule included 7 predictors (suboptimal adherence, CD4 cell count < 100 cells/microL, drug and/or alcohol abuse, highly ART experienced, missed > or = 1 appointment, prior virologic failure, and suppressed < or = 12 months) and appropriately stratified patients in the validation data set into low-, medium-, and high-risk groups, with 1-year virologic failure rates of 3.0%, 13.0%, and 28.6%, respectively.


CONCLUSIONS
A risk score based on 7 variables available in the EHR predicts HIV virologic failure at 1 year and could be used for targeted interventions to improve outcomes in HIV infection.
Robbins
Gregory K
GK
Harvard Medical School, Boston, Massachusetts, USA. grobbins@partners.org
Johnson
Kristin L
KL
Chang
Yuchiao
Y
Jackson
Katherine E
KE
Sax
Paul E
PE
Meigs
James B
JB
Freedberg
Kenneth A
KA
D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D001900:Boston; D003625:Data Collection / Q000379:methods; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology*; D006801:Humans; D008297:Male; D008404:Massachusetts; D016347:Medical Records Systems, Computerized; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors; D017211:Treatment Failure; D019562:Viral Load
D019380:Anti-HIV Agents