title: Development and application of a new measure of engagement in out-patient HIV care.
abstract: Commonly used measures of engagement in HIV care do not take into account that the frequency of attendance is related to changes in treatment and health status. This study developed a new measure of engagement in care (EIC) incorporating clinical factors.
  
  
  
  We conducted semi-structured interviews with eight HIV physicians to identify factors associated with the timing of patients' next scheduled appointments. These factors informed the development of an algorithm to classify each month of follow-up as "in care" (on or before the time of the next expected attendance) or "out of care" (after the time of the next expected attendance). The EIC algorithm was applied to data from the UK Collaborative HIV Cohort (UK CHIC) study, a large clinical cohort study.
  
  
  
  The interviews indicated that time to next appointment varied depending on psychosocial and physical comorbidities, and clinical factors (time since diagnosis, AIDS diagnosis, treatment status, CD4 count and viral load). The resulting EIC algorithm was applied to 44 432 patients; 83.9% of the 3 021 224 person-months were "in care". Greater EIC was independently associated with older age, white ethnicity, HIV acquisition through sex between men, current use of antiretroviral therapy (ART), a higher nadir CD4 count, later calendar year and being seen at the clinic for the first time within the last year.
  
  
  
  This algorithm describing engagement in HIV care incorporates a time-updated measure of patients' treatment and health status. It adds to the options available for measuring this key performance indicator.
authors.affiliation: Research Department of Infection and Population Health, University College London, London, UK.
authors.forename: A R
authors.initials: AR
authors.lastname: Howarth
authors.affiliation: Research Department of Infection and Population Health, University College London, London, UK.|Royal Free London NHS Foundation Trust, London, UK.
authors.forename: F M
authors.initials: FM
authors.lastname: Burns
authors.affiliation: Barts Health NHS Trust, London, UK.
authors.forename: V
authors.initials: V
authors.lastname: Apea
authors.affiliation: Research Department of Infection and Population Health, University College London, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Jose
authors.affiliation: Research Department of Infection and Population Health, University College London, London, UK.
authors.forename: T
authors.initials: T
authors.lastname: Hill
authors.affiliation: Public Health England, London, UK.
authors.forename: V C
authors.initials: VC
authors.lastname: Delpech
authors.affiliation: Royal Free London NHS Foundation Trust, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Evans
authors.affiliation: Research Department of Infection and Population Health, University College London, London, UK.
authors.forename: C H
authors.initials: CH
authors.lastname: Mercer
authors.affiliation: Centre for Behaviour Change, University College London, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Michie
authors.affiliation: Department of Applied Health Research, University College London, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Morris
authors.affiliation: UK Community Advisory Board, London, UK.
authors.forename: M
authors.initials: M
authors.lastname: Sachikonye
authors.affiliation: Research Department of Infection and Population Health, University College London, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Sabin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000553:Ambulatory Care / Q000706:statistics & numerical data*; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000175:diagnosis* / Q000188:drug therapy*; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D010342:Patient Acceptance of Health Care; D006113:United Kingdom; D055815:Young Adult
keywords: 
  HIV
  ; cohort study; out-patient care; patient engagement; retention measure