Knowledge Item: CA-Medical Outcomes-52
CD4 Count Outcomes and Type of Project

CD4 count outcomes are examined to determine how many patients had clinically significant reductions in viral load as a function of participation in the Cooperative Agreement Projects.

Using as a criterion for success that the patient's CD4 count increased at least 50 points from the baseline assessment, 47.2 percent of the male patients and 47.9 percent of the female patients were found to have a clinically significant increase in their CD4 counts. A higher percentage of the patients in the University Comprehensive Healthcare Clinics had a clinically significant increase in CD4 counts than did patients in the Managed Care Clinics; the change was, however, only found among male patients. Analyses controlling for the patient's initial CD4 count do not explain the differences in change in CD4 counts.

The following charts are predictive exhaustive CHAID (CHi-square Automatic Interaction Detector) models. Note that in this diagram the green bars represent a CD4 count change of less than +50 and the blue bars represent a change in CD4 count of +50 or more. 

Dependent Variable CD4 Outcome
Potential Splitter (Predictor) Type of Clinic
Potential Splitter (Predictor) Gender

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Click graphic to expand. (IE 6 users may also have to click the graphic expansion button in the new window.)

Dependent Variable CD4 Outcome
Potential Splitter (Predictor) CD4 Classification
Potential Splitter (Predictor) Type of Clinic

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Click graphic to expand. (IE 6 users may also have to click the graphic expansion button in the new window.)

Dependent Variable CD4 Outcome
Potential Splitter (Predictor) Gender
Potential Splitter (Predictor) Type of Clinic

Click graphic to expand. (IE 6 users may also have to click the graphic expansion button in the new window.)
Click graphic to expand. (IE 6 users may also have to click the graphic expansion button in the new window.)

More Information:     CHAID and CHAID Diagram

The definition of outcome used in this Knowledge Item is based on the medical literature and the attempt to define what is considered a clinically significant outcome for a single patient in treatment. Note that a successful outcome is coded if the patient meets the medical criterion for positive change in health status at least one time during the course of the treatment episode. Other Knowledge Items (for example: Knowledge Item: CA-Medical Outcomes-14, -15, -18, -19, -22, -23) use a technique called Hierarchical Linear Modeling (HLM) which codes outcome as the overall trend in the patient's scores through the observed treatment episode. The HLM definition of a successful outcome is a stringent one that assumes that there is not a relapse, while the current definition acknowledges that in a progressive disease such as HIV/AIDS, there may be relapse to the baseline state even after a positive response to therapy.

A related set of results using an alternate definition of medical outcome is presented in Knowledge Item: CA-Medical Outcomes-14.

Knowledge Item Citation: Huba, G. J., Melchior, L. A., Panter, A. T., and the HRSA/HAB SPNS Cooperative Agreement Steering Committee (1998-2001). Knowledge Item: CA-Medical Outcomes-52 from HRSA/HAB's SPNS Cooperative Agreements on Innovative Models of Care, The Measurement Group Knowledge Base on HIV/AIDS Care, Online at www.TheMeasurementGroup.com.

Last Updated: March 25, 2005; data through June 15, 1999; analyses conducted November 2000.


Knowledge Base Citation: The Knowledge Base and this Knowledge Item were designed and authored by G. J. Huba, Ph.D.; in collaboration with Lisa A. Melchior, Ph.D.; A. T. Panter, Ph.D.; and the staff of The Measurement Group. Cite this work as "Huba, G. J., Melchior, L. A., and Panter, A. T. (1998 - 2001). The Measurement Group Knowledge Base on HIV/AIDS Care. On the World Wide Web: http://www.TheMeasurementGroup.com."

Questions or Comments: Contact The Measurement Group.

Use of Knowledge Base Information: Acceptable Uses and Limitations.

Collaborators from Participating Projects: Cooperative Agreement Steering Committee 1999. 

Participating Projects: This Knowledge Base is based on the service delivery experiences of 27 Cooperative Agreement Projects on Innovative Models of HIV/AIDS Care. These projects and the Evaluation and Dissemination Center which produced this Knowledge Base were funded by the Health Resources and Services Administration (HRSA), HIV/AIDS Bureau (HAB) as Special Projects of National Significance (SPNS) between 1994 and 1999. Click the Model Programs button above for descriptions of the projects that contributed to this specific Knowledge Item, a list of key staff, and project grant numbers.

Why This Evaluation was Conducted: Editorial.

More Information: Design of this Knowledge Base.

Recommended Citation Format for Web Materials: American Psychological Association Publication Manual Section, Revised 2001.

Work on the Knowledge Base and the cross-cutting evaluation was supported in part by Grant Number 5 U90 HA 00030-05 from the Health Resources and Services Administration (HRSA), HIV/AIDS Bureau's (HAB) Special Projects of National Significance (SPNS). The contents of this Knowledge Base are solely the responsibility of The Measurement Group and do not necessarily represent the official views of HRSA or HRSA/HAB's Special Projects of National Significance nor may they represent the positions of the individual grantees whose projects are included in the cross-cutting evaluation.

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