Enhanced collection of laboratory data through the utilization of data in existing databases, strengthened active surveillance efforts, the identification of labs not reporting to surveillance, and an increased number of electronic reports, improved the completeness of CD4, VL, and OI data in national HIV surveillance. Although no true standard was available for comparison, the percentages of persons diagnosed with HIV who had stage of disease assigned or who were linked to care were up to 10% higher with the enhanced data collection.
The collection of more complete data provides a more accurate picture of disease severity and linkage to care. Based on CD4 and VL laboratory tests performed within 3 months following diagnosis, we estimated that 78.5% of persons diagnosed in the five states were linked to care. This finding is somewhat higher than what was observed through an analysis of persons newly diagnosed with HIV infection in New York City, where the time between the first positive Western blot test and the first CD4 and/or VL result reported to surveillance was used to indicate the time period from the initial HIV diagnosis (non-AIDS) to the first HIV-related medical care visit [6
]. Of 1,928 newly diagnosed persons in New York City in 2003, an estimated 63.7% initiated care within 3 months of diagnosis.
Overall, linkage to care needs strengthening to reach the goal outlined in the National HIV/AIDS Strategy of 85% of newly diagnosed patients linked to clinical care within 3 months of diagnosis [7
]. We found a significantly higher proportion of persons with no CD4 or VL test results among blacks/African Americans as compared to whites which suggests that a racial disparity may exist among newly diagnosed persons who receive care. This finding is consistent with other studies that have documented an association between racial factors and disparities in HIV-related healthcare [8
] and may be related to a complex interaction between health care, public health, and social factors [12
]. These data also show that younger persons aged 15-29 were less likely to have a CD4 or VL test, as compared to persons aged 30 and above. The disparity seen in age may be a function of the large proportion of young adults that are uninsured [13
], and serves to highlight the potential gap in accessing care between age groups. Additional interventions are needed to meet the goals of the National HIV/AIDS Strategy on linkage to care and the reduction of HIV-related disparities.
The initiation and frequency of laboratory testing and interpretation of laboratory results can be used to make inferences about the quality of health care that HIV-infected persons receive. Laboratory testing that occurs shortly after HIV diagnosis implies the successful linkage to health care. Serial CD4 and VL testing suggests utilization of ongoing care compared with a one-time visit. If the frequency of serial laboratory tests meet clinical management testing guidelines (e.g., every 3-4 months after initial diagnosis baseline measurement), it suggests receipt of higher quality care than less frequent laboratory testing would.
Persons without CD4 or VL testing following HIV diagnosis may represent persons with unmet healthcare needs. To address unmet healthcare needs and develop effective interventions, it is important to understand the barriers to accessing care such as lack of health insurance coverage [14
], unsuccessful patient notification of positive HIV test results [16
], denial, poverty, mental illness, lack of transportation, and homelessness [19
]. States have a responsibility to provide unmet health care need estimates to the Health Resources and Services Administration (HRSA), which oversees the Ryan White CARE Act. Surveillance data could be used to provide estimates of persons not in care and, therefore, assist states in meeting this federal reporting obligation.
OI data can be a useful indicator of clinical outcomes for HIV-infected persons in care. Based on OI data reported within 3 months following diagnosis, we estimated that 12.3% of persons diagnosed in the five states had at least one OI; PCP was the most frequently reported. A similar finding was observed through an analysis of a population-based survey of persons in HIV-related medical care in King County Washington, selected health districts in Louisiana, and the state of Michigan [22
]. Of all HIV-infected persons in care in these areas in 1998, 11.3% (CI, 8.8–13.9) had at least one OI diagnosis and PCP was the most commonly diagnosed.
There are some limitations to consider when interpreting our findings. First, if laboratory data reported to surveillance are incomplete, the methods outlined may underestimate the prevalence of persons with access to medical care. In addition, the contribution of individuals who may be diagnosed in a jurisdiction reported to a state HIV program but then leave the state is unknown. From the local surveillance perspective, these individuals may not have begun care (i.e., evidence of lab testing) but received care after they moved out of jurisdiction. In Louisiana, the number of cases reported to surveillance and the completeness of laboratory data collected after August 2005 was impacted by Hurricane Katrina, as several clinical sites were closed and complete medical record abstraction was not possible.
In jurisdictions that have laws or regulations for laboratory reporting of all HIV-related tests, private and public laboratories must report all test results to the respective health departments. During the data collection period, changes in CD4 and VL reporting laws may have contributed to improvements seen in the completeness of laboratory reporting. For example, the laboratory reporting requirements were significantly broadened in New York State in June 2005, the start of the 12-month diagnosis period, to require the reporting of any VL result and all CD4 counts and percentages. Prior to this change, only detectable VLs and CD4 counts less than 500 cells/µL or percentages less than 29% were reportable. In July 2005, Michigan also revised their regulations to require the reporting of all CD4 and VL results.
In general, surveillance programs believe they are receiving the vast majority of HIV test results; but, unless a state is actively monitoring the number of laboratories reporting to them and the volume of reports, they cannot know for certain. Instances where laboratory testing may change (e.g., the provider decides to use another laboratory or the primary laboratory contracts with a new laboratory for specialized testing) may not necessarily be identified by a surveillance program. Active surveillance and medical record abstraction can help to obtain more complete laboratory data and identify laboratories that may not be reporting to HIV surveillance. The electronic transmission of HIV-related laboratory test results enhances the completeness, timeliness, and accuracy of reporting to surveillance programs [23
]. Although many surveillance programs have received data electronically for years, many still need improvements or enhancements to implement and maintain the system. HIV surveillance programs are currently using software called eHARS that has the capacity for storage of all laboratory results and the ability for electronic laboratory data to be imported. To ensure that all laboratory results are reported to surveillance at the national level, state and local surveillance programs must ensure that all laboratory results, including those stored in auxiliary databases, are entered into eHARS software and transmitted to CDC.
The National HIV/AIDS Strategy proposes to reduce new HIV infections, increase access to care and improve health outcomes for people living with HIV, and reduce HIV-related disparities [8
]. Data collected through the national HIV surveillance system can be used to monitor the outcomes of the national strategy; however the validity of these measures is dependent upon the completeness and quality of surveillance data. Monitoring outcomes such as linkage to care and racial/ethnic disparities among persons who are virally suppressed is particularly dependent upon complete reporting of all HIV-related laboratory results to surveillance.