Guidelines on surveillance among populations most at risk for HIV

4.2. Step 8: Evaluate the systemAny surveillance activity that is implemented must be evaluated regularly to ensure that it is meeting itsobjectives (86).More informal routine monitoring is also useful. Reflect on these aspects of the surveillance system: Frequency and timeliness of data collection Appropriateness of populations under surveillance Consistency of sites and groups measured over time Coverage/representativeness of the groups for the target populations.When evaluating the HIV surveillance system, include the following: Can the system describe where new infections are occurring? Can the system describe how the epidemic is changing? Are the data being used to inform programming? Are the right data elements being collected? Is the choice of methodology appropriate for the situation? Does the data collection process adhere to the protocol? Has the analysis been conducted with appropriate tools/methods, including weighting, adjustment fordesign effects, etc.? Is data collection restricted to essential data? Is there appropriate process documentation? Does the activity conducted meet ethical standards?Look for additional information on surveillance evaluation guidelines on the WHO and UNAIDS web sitesin 2011.34