CNICS cohort data are harmonized across eight contributing sites in nine domains as detailed below:
a.     Demographic
b.     Diagnosis
c.     Laboratory
d.     Medication
e.     Health Care Utilization
f.      Vital Status
g.     Patient Reported measures and Outcomes (PROs)
h.     Antiretroviral Resistance
i.      Biologic Specimens

a.     Demographic Data
Demographic information in CNICS is collected at the time a patient initiates care using standard categories and includes: sex, birth year, race and Hispanic data classified by the Health Resources and Services Administration standard coding, and risk factors for HIV acquisition coded according to the
cohort age distribution 2015
1993 Centers for DiseaseControl and Prevention classification system (1993 Revised Classification System for HIV Infection and Expanded Surveillance Case Definition for AIDS Among Adolescents and Adults. MMWR Recomm Rep 1992;41(RR-17):1-19). The distribution of demographic characteristics in the CNICS cohort is linked in an attached table. VIEW TABLE Age distribution of the CNICS cohort at patients' initial visit and most recent visit, at which time 30% of the cohort was >50 years old is depicted at right (click to expand figure).

b.     Diagnosis Data
1.  Diagnoses are prospectively recorded in the Electronic Medical Record (EMR) by the treating clinician
2.  Historical diagnoses are collected at the patient’s initial visit to a CNICS site and coded as ‘patient reported’ with       or without outside documentation
3.  Diagnosis data are mapped to a standardized set of diagnosis codes and harmonized across CNICS sites
4.  Diagnoses collected in CNICS are 1) verified via medical record review and/or adjudication, 2) confirmed via        laboratory test results and/or medications, and 3) unconfirmed. VIEW DATA

c.     Laboratory and Vital Signs Data
Laboratory test results are uploaded directly from clinical laboratory medicine systems and harmonized across CNICS sites implementing standardized units and clinical interpretations. In addition, CNICS captures vital signs including blood pressure, height and weight. VIEW DATA

d.     Medication Data
- Classes of medications captured in CNICS include antiretroviral, antihypertensive, diabetes, psychiatric, and lipid lowering
- Medications prescribed are entered into the EMR by clinicians (including start/stop dates), and pharmacy prescription fill/refill data are available at some sites, which are used to compute courses of therapy
- Antiretroviral medication data are verified through medical record review, and historical antiretroviral treatment collected at the patient’s initial visit to a CNICS site is coded as to completeness and level of date precision
- The addition of new classes of medications in CNICS is guided by the expanding research agenda. Medication data captured in CNICS are compiled in a downloadable table. VIEW DATA

e.     Health Care Utilization Data
Outpatient encounter and appointment systems, as well as inpatient systems, are the source of health care utilization data in CNICS. VIEW DATA

f.     Vital Status
- CNICS sites use local procedures to track deaths and maintain death registries
- CNICS subscribes to the Social Security Death Index (SSDI) that CNICS sites query semiannually to ensure complete ascertainment of death dates
- Sites collect cause of death data from State Death Certificates, the National Death Index (NDI)+ as ICD-10 codes, and through medical record review. The completeness of cause of death data varies by CNICS site with cause of death unknown for approximately 25% of the CNICS cohort overall

g.     Patient Reported measures and Outcomes (PROs)
PROs are collected at CNICS sites during routine clinical encounters using validated instruments administered by touch-screen tablets or PCs connected to a wireless network with SSL/TLS encryption.  Patients complete PRO assessments every four to six months and results are available at the time of the encounter for use in clinical care. Over 70,000 PRO assessments completed by over 14,000 patients are available for research in the following domains: VIEW DATA

h.     Antiretroviral Resistance Data
CNICS has made considerable progress in overcoming the proprietary and technical challenges of collecting resistance data from commercial laboratories for each site.  CNICS captures diverse viral resistance data including full nucleotide genotype, phenotype, and tropism assays with the capability for expansion to include new drug targets

i.     Biologic Specimens
CNICS provides access to biologic specimens linked to a patient’s comprehensive clinical data in the CNICS Research Platform. Information about the CNICS specimen repository is available HERE