Viral load test reports: a description of content from a sample of US laboratories

Human immunodeficiency virus (HIV) RNA testing (viral load testing) is increasingly important in the care of patients infected with HIV-1 to determine when to initiate, monitor, and change antiretroviral therapy. Patient viral load testing information is communicated to the clinician through the laboratory test report.

To examine the format and information used in reporting viral load testing results and determine the clarity of the information provided in these reports.

Patient test reports with all personal identifiers removed were requested of viral load testing laboratories participating in a telephone survey of laboratory practices. Hospital, independent, health department, and "other type" laboratories identified as university-associated laboratories participated in the telephone survey.

Thirty-seven unique test reports were collected. All laboratories reported results in copies/mL, while 14% also reported results as "log(10) copies/mL." The test kit was identified by only 24% of the laboratories. Reportable ranges were specified by 70% of the laboratories, but there was considerable variation in terminology. One laboratory reported a viral load copy number below the manufacturer's test kit lower limit of sensitivity. The layout and format differed among reports. Some results were expressed in log(10), others contained nonsignificant integers, while others contained exponential numbers. Supplemental information in some reports included previous patient test results and significance of changes from baseline. The format of some reports made it difficult to read the report information and interpret the testing results.

This study emphasizes the importance of standardizing the reporting of HIV-1 viral load test results to minimize result misinterpretation and incorrect treatment.