The University of Washington HIV Cohort


The University of Washington (UW) HIV Cohortis comprised of HIV-infected patients receiving care at Harborview Medical Centerís Madison HIV Clinic and the University of Washington Medical Centerís Virology Clinic in Seattle Washington from January 1, 1995 to the present. Harborviewís HIV Clinic is the largest single provider of medical care to HIV-infected individuals in the northwestern United States. Comprehensive data on the UW HIV Cohort from the UW Electronic Medical Record (EMR) and other sources are integrated within the University of Washington HIV Information System (UWHIS). The UW EMR was designed to capture standardized HIV-related data including information collected at patientsí initial intake visit regarding prior antiretroviral treatment and diagnosis history.


UWHIS data include:

              Patient demographic and health insurance information

              Provider and social work/case management data

              Outpatient and inpatient-stay visits

              Laboratory and procedure data

              Pharmacy dispensing data

              Diagnosis data

              Routine outpatient measurement of:

o        Vital signs: blood pressure, heart rate, respiratory rate, temperature

o        Weight

o        Height

o        Health-related quality-of-life


UWHIS also integrates data on the UW HIV Cohort from:

              The UW HIV Registry of patients who consent to participate in research

              The UW HIV Historical Database of information obtained from medical record review

              The UW HIV Specimen Repository Index to patientsí stored plasma and PBMCs

              Death database verified with the U.S. Social Security Death Index


Sources of UWHIS Data:

     Laboratory data within the UWHIS are sent via a real-time interface from the UW Laboratory Medicine system and include results of all tests performed on the UW HIV Cohort as part of routine clinical care such as CD4+ T cell count, plasma HIV-1 RNA, and hematologic measurements, serum chemistries and lipid levels, and genotypic viral resistance testing. Laboratory data are verified in the UWHIS using data type-specific methods such as surveillance for coding changes and outliers, and processed for research including codification of free text result fields.


     A major strength of the UWHIS is the electronic transfer of detailed pharmacy dispensing data from the UW Pharmacy system. The UW HIV Cohort is unique in that over 90% of patients receive all their medications from the on-site pharmacy. Prescription fill/refill data including the medication strength, dose, sig, start date, and refill dates for all outpatient medications and inpatient discharge medications dispensed anywhere in the UW system are entered into the UW Pharmacy system by pharmacy staff at the time medications are dispensed, sent via a real-time interface to the UW EMR, and downloaded into the UWHIS. Antiretroviral medications data can be processed to define regimens, courses of treatment, and antiretroviral medication refill adherence.

     Clinician data entry is limited to selecting diagnoses addressed at each clinical encounter from a web-based pick list containing standardized diagnosis labels mapped to International Classification of Diseases 9th revision, Clinical Modification (ICD-9) coding that generates billing data for the visit and automatically updates patientsí problem lists. Comprehensive diagnosis data from all outpatient and inpatient encounters are updated routinely and systematically verified in the UWHIS through event driven audits, monitoring and evaluation of changing incidence rates, and ongoing medical record review.


     Death data are verified with the U.S. Social Security Death Index.


     Blood samples are obtained three times each year from participating patients and plasma and PBMCs are stored in the UW HIV Specimen Repository.


Data from the UWHIS are provided to investigators

              To identify patients meeting entry criteria for recruitment into prospective studies

              To assess study feasibility for grant preparation

              For clinical and translational HIV research requiring longitudinal patient data and biological specimens.


The UW HIV Cohort currently consists of 2,852 patients (May 2005) with the following characteristics:







††††† Female

†††††† 403

†† 14%

††††† Male

††† 2,422

†† 85%

††††† Transgendered

†††††††† 27

†††† 1%




American Indian

†††††††† 65

†††† 2%


†††††††† 60

†††† 2%


††††††† 528

†† 19%


†††††† 278

†† 10%


††† 1,871

†† 66%


†††††††† 50

†††† 2%

Age (at initial visit)




†††††††† 29

†††† 1%


†††††† 552

††† 19%


††† 1,302

††† 46%


†††††† 761

††† 27%


†††††† 206

††††† 7%