Late HIV diagnosis

Export Indicator

Percentages of people living with HIV with the initial CD4 cell count <200 cells/mm³ and <350 cells/mm³ during the reporting period
What it measures

Proportions of people with a CD4 cell count <200 cells/mm³ and <350 cells/mm³  of those who had an initial CD4 count during the reporting period 

Rationale
As countries scale up HIV services, it is important to monitor whether people are diagnosed at an earlier stage and what percentage of the people are still diagnosed at a late stage.
Numerator

1. Numbers of people living with HIV with an initial CD4 cell count <200 cells/mm³

2. Numbers of people living with HIV with an initial CD4 cell count <350 cells/mm³ during the reporting period

Denominator

Total number of people living with HIV with an initial CD4 cell count during the reporting period

Calculation

Numerator/denominator

Method of measurement
Based on data from laboratory information systems and from the records of people in treatment. Data can be compiled from health services registries, case report forms or laboratory information systems.
Measurement frequency

Annual

Disaggregation
  • 0-14 years for children and 15 years and older by sex (men and women) for adults
Explanation of the numerator

People living with HIV whose initial CD4 lymphocyte count was less than 200 cells/mm³ and people living with HIV whose initial CD4 lymphocyte count was less than 350 cells/mm³ in the reporting period. Reporting on the number of people with a CD4 lymphocyte count less than 350 cells/mm³ also should include those with a CD4 lymphocyte count less than 200 cells/mm³

Explanation of the denominator

Number of people living with HIV who had an initial CD4 lymphocyte count in the reporting period.

Strengths and weaknesses
The initial CD4 count is not necessarily calculated at the time of diagnosis or in a timely manner. The available data may not correspond to all individuals diagnosed in the reporting year.
 
This indicator does not distinguish between people given a late diagnosis and those who sought treatment late. Differentiating them requires examining the diagnosis date and the date of the initial CD4 lymphocyte count. Dates differing by more than one month may indicate a delay in being linked to care. A difference of less than one month suggests a late diagnosis. In addition, late diagnosis and late linkage to care may coincide in the same person.
 
The available data may not include all individuals diagnosed in the reporting period.