| Field Name | Format | Description |
|---|---|---|
| PATIENT | Character or Numeric | *Required Code to identify patient (Cohort Patient ID) |
| CD4_D | YYYY-MM-DD | *Required Date of measurement |
| CD4_D_A | Character < = Before this date D = Exact to the date M = Exact to the month Y = Exact to the year > = After the date U = Unknown | Date approximation for CD4_D |
| CD4_V | Numeric | Value of CD4 measurement |
| CD4_U | Numeric 1 = cells/mm3 2 = % | *Required Unit of measurement |