Table 2.
Measurements collected at each data update in the Antiretroviral Therapy Cohort Collaboration
| Update | Cohorts N | Patients N | Data collected |
|---|---|---|---|
| 2001 | 13 | 12 574 | Demographic variables: age, sex, risk factors for transmission |
| Laboratory variables: CD4 cell counts and viral loads at start of ART and at 6 months | |||
| Clinical variables: ART start date, ART drug regimen at baseline, CDC disease stage at start of ART | |||
| Outcome variables: AIDS events, last visit date, death, death date | |||
| 2004 | 12 | 22 217 | As above |
| 2006 | 15 | 49 040 | As above, plus: Demographic variables: Race/ethnicity, geographical origin based on country of birth, nationality |
| Laboratory variables: CD4 cell count closest to event/death and last count during treatment, with dates. At least one 3-year measurement of each prognostic variable (CD4 cell count, HIV-1 RNA plasma viral load, haemoglobin), with dates and an indicator variable for being on/off treatment, and whether patient experienced virological failure (defined as an a viral load of > 500 during treatment) after 6 months and within 3 years of initiating treatment | |||
| Clinical variables: Total number of ART drugs and classes to which patient was exposed at 3 years, whether patient has changed treatment from initial regimen, as ascertained when available | |||
| Outcome variables: Causes of death, loss to follow-up indicator, and reason for loss to follow-up | |||
| 2008a | 18 | 59 483 | As above, plus: |
| Demographic variables: current alcohol, injection-drug use and smoking | |||
| Laboratory variables: longitudinal measurements of CD4 cells and viral load are now available, as well as other longitudinal laboratory measures (such as alanine aminotransferase, creatinine) and virology measures (such HCV/HBV status) | |||
| Clinical variables: Detailed information about start/stop dates of drugs and reasons for drug changes. | |||
| 2010 | 19 | 74 048 | As above |
aData were collected according to the HICDEP (see http://hicdep.org) format from the 2008 update onwards. This enabled collection of longitudinal data.
Abbreviations: ANRS, Agence Nationale de Recherche SIDA; ART, antiretroviral therapy; CDC, US Centers for Disease Control and Prevention; HBV, hepatitis B virus; HCV, hepatitis C virus; IDU, injection-drug user.