• Ability of Patients with HIV Infection to Predict Changes in Their Own CD4+ Lymphocyte and Viral Load Measurements (Poster 716)
  Authored by D. Kaswan, L. Strasfeld, J. Shuter, Montefiore Medical Center, Bronx, NY

This was an unusual presentation. The authors, from the Montefiore Medical Center in New York, wanted to know if patients were able to predict changes in their own CD4+ lymphocyte and viral load measurements. Patients predicted their own CD4 and viral load count using a scale with five possibilities:

1. Much higher than the last visit.

2. Higher than the last visit.

3. Same as the last visit.

4. Lower than the last visit.

5. Much lower than the last visit.

They analyzed 195 CD4+ predictions and 198 viral load predictions by 161 HIV-infected patients.

They discovered that patients were able to predict better than just by chance what their viral load and CD4 were going to be. In fact, they were remarkably consistent: predictions of higher CD4+ counts were associated with actual CD4+ increases in 65% of the cases, and predictions of lower CD4+ counts were associated with actual CD4+ decreases in 73% of the cases (p=0.002). Predictions of higher viral load were associated with actual viral load increases in 45% of the cases, and predictions of lower viral load were associated with actual viral load decreases in 87% of the cases (p<0.001).

It is obvious that no one can "sense" his or her own viral load or CD4 count and that asking our patients will never substitute any actual determinations of viral load and CD4 cell counts. This probably represents a surrogate marker of adherence to antiretroviral therapy. What probably happened is that these patients made their predictions based on their adherence since their last CD4 and viral load count results.

Can this be used in clinical practice? Maybe. Especially if this test (a very simple question which is simple to administer) correlates well with other more standard markers of adherence like pill counts, MEDCAPS, etc. That type of study will be necessary to validate the results of this rather unusual study.

Adherence is the strongest predictor of virologic success. Finding ways to better evaluate it and defining interventions that would improve it in patients at high risk for failure is one of the most important goals in antiretroviral therapy now.