Table 2.

An overview of the eight subsystems before and after the data integration initiative

Subsystem	Purpose	Before integration	After integration
HIV/AIDS case reporting	To collect demographic and health data on individuals who have tested positive for HIV infection. To record follow-up information on cases.	Before 2005, data were collected in paper and pencil format and submitted up the reporting chain by post. In 2005, China instituted a national web-based infectious disease case reporting system that improved data reporting and use.	The statistics module of the case reporting system was supplemented to ensure all relevant statistics are provided. New function modules were developed to supplement the HIV/AIDS component of the national, web-based infectious disease case reporting system. These new modules included: the generation of case follow-up reminders to ensure local health-care workers know when to follow-up cases; and an outbreak alert feature flagging increased case reporting.
HIV sentinel surveillance	To monitor trends over time in HIV prevalence and key risk behaviours among key populations.	Before 2005, local HIV sentinel surveillance sites sent encrypted data in EpiInfo format to the NCAIDS via e-mail.	The HIV sentinel surveillance subsystem and BSS subsystem were integrated into one surveillance subsystem in 2008. Terminal software was developed to collect data offline and submit data online to the platform for higher level CDC downloading and analysing.
HIV BSS	To monitor trends over time in HIV prevalence and risk behaviours among key populations.	Before 2005, local HIV sentinel surveillance sites sent encrypted data in EpiInfo format to the NCAIDS via e-mail.
HIV testing and counselling	To collect data on access to testing services. To monitor service coverage and utilization.	Before 2008, VCT information was reported quarterly using a simple report form by post. Local health-care workers had to fill out one counselling questionnaire and a separate testing questionnaire for a participant, and complete a quarterly reporting form to be submitted via post or e-mail to provincial CDC. Similarly, 32 provincial aggregated forms were then submitted to the central CDC.	An integrated questionnaire was developed to collect both counselling and testing information. All information pertaining to VCT clinics is easy to access ensuring policy makers can easily ascertain and monitor the coverage and efficiency of VCT.
Behavioural interventions among high-risk groups	To collect data on population size, intervention coverage, and key behavioural indicators (e.g. number of sexual contacts).	Before 2008, each county submitted behavioural intervention information via e-mail on a quarterly basis using an Excel spreadsheet. Data were aggregated at each level, with 32 aggregated provincial forms submitted to the NCAIDS.	Each county level CDC reports data on behavioural interventions for high-risk groups to the platform directly, including the estimated size of each high-risk group, the number of contacts with each group, and the related intervention information in their area of jurisdiction. From this, the data are aggregated into prefectural, provincial and national data sets and the CDC at each level is able to review the aggregated data at their level and below. If data has not been submitted, this can be easily identified by the next administrative level of the CDC, ensuring expedient information management.
ART for adults	To provide data on treatment needs for HIV-positive adults. To provide data on the effectiveness of adult ART regimens.	In 2004, the NCAIDS established a nationwide observational cohort of adults on ART. An electronic ART database system was established, and standardized case report forms (CRFs) were completed at each patient visit and faxed to the NCAIDS via DataFax.7,8 As the population of patients receiving ART swelled with the expansion of ART programs across the country, the DataFax system at the NCAIDS was no longer able to handle the volume of CRFs being submitted. By the end of 2008, there were 1574 ART sites and 58 795 HIV-positive adults receiving ART.	A web-based ART treatment information system was implemented in 2009. Terminal software was used to collect data instead of DataFax. Data can be entered and/or uploaded at any time.
ART for children	To provide data on paediatric treatment needs for HIV-positive children. To provide data on paediatric ART regimens.	A subsystem to monitor ART among HIV-positive children was established in 2008.	The data collection tool was modified.
MMT	To provide data on injection drug user treatment needs. To provide data on MMT program operations.	Before 2008, incomplete patient information and clinic information were collected from each MMT clinic using a data collection tool developed by the NCAIDS. The data were compressed and submitted to the NCAIDS via e-mail.	The establishment of the MMT subsystem integrated all MMT clinics into one platform for sharing information for the first time. It is the most complicated of all the subsystems due to its abundance of information, including demographic information with photos, laboratory information of HIV, syphilis and hepatitis C testing results, methadone dosage levels, patient clinic transfer information, clinic information, staff information, logistic information and statistics.
County-level background information	To provide an understanding of the contexts in which local HIV epidemics are unfolding.	Before 2008, there was no such subsystem.	Information from all 2893 counties was annually updated at the platform through internet. County-level background information provides an understanding of the contexts in which local HIV epidemics are unfolding. Information collected includes: demographic information; information on local infrastructure; the number and types of entertainment establishments; HIV/AIDS epidemic characteristics; high-risk population size estimates; AIDS orphan population size estimates; and the number of AIDS orphans receiving care and support.