title: Migration distorts surveillance estimates of engagement in care: results of public health investigations of persons who appear to be out of HIV care.
abstract: BACKGROUND
  Prevention and clinical efforts are increasingly focused on improving the HIV care cascade, the sequential steps from diagnosis to engagement in care and viral suppression. Monitoring of this cascade is largely dependent on HIV laboratory surveillance data. However, little is known about the completeness of these data or the true care status of individuals for whom no data are reported.
  
  
  METHODS
  We investigated people presumed to be living with HIV/AIDS in King County, WA, who had no laboratory results reported to HIV surveillance for at least 1 year between 2006 and 2010. We determined whether each person had relocated, died, or remained in the county.
  
  
  RESULTS
  Of 7379 HIV-infected people presumed living in King County, 2545 (35%) had 1 or more 12-month gap in laboratory reporting. Among these individuals, 47% had relocated, 7% died, and 38% remained in King County; we were unable to determine the status of 8%. Of individuals remaining in the area, 91% had evidence of returning to or being in HIV care. Case investigations reduced the proportion of individuals thought to be out of care in 2011 from 27% to 16%.
  
  
  CONCLUSIONS
  Investigations of individuals without laboratory results reported to HIV surveillance identified large numbers of people who are no longer living in the area. Our findings suggest that current estimates of the HIV care cascade may be too pessimistic and that individual case investigations are required to accurately define the size and composition of the population of people living with HIV in local areas.
authors: From the *Public Health Seattle & King County, Seattle, WA; †Department of Epidemiology, University of Washington, Seattle, WA; and ‡Department of Medicine, University of Washington, Seattle, WA and Center for AIDS and STD, Seattle, WA.
authors: Susan E
authors: SE
authors: Buskin
authors: James B
authors: JB
authors: Kent
authors: Julia C
authors: JC
authors: Dombrowski
authors: Matthew R
authors: MR
authors: Golden
mesh_terms: D000293:Adolescent; D000328:Adult; D019380:Anti-HIV Agents / Q000008:administration & dosage*; D018791:CD4 Lymphocyte Count; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000453:epidemiology*; D006297:Health Services Accessibility / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D011634:Public Health; D014171:Transients and Migrants; D014481:United States; D019562:Viral Load
chemical_list: D019380:Anti-HIV Agents