Table 1.

Characteristics of population-based and clinic-based continuum of services.

Characteristic	Population-based surveys	Clinic-based reporting
Population	Survey target population (general population or select key population)	Persons accessing services
Geographic scale	Defined by sampling area	Clinic, sub-national, and national level
Timing of data collection	Periodic	Continuous
Data source	Survey respondents	Routine clinic records
Data level	Individual level	Clinic level (typically)
Data accuracy	Subject to reporting bias, respondent health literacy, sampling error	Subject to clinic logbook quality and transcription errors
Accuracy of biomeasures	Subject to accuracy of recall (CD4+T cell count, viral load) but ameliorated if biomarkers are measured as part of survey	Subject to quality of data entry and data transcription
Estimating proportion accessing services	Yes	Not usually reported or difficult
Assessing determinants of service uptake, lack of service uptake, or exiting the continuum of services	Feasible	Not feasible (service uptake) or not always done (evaluating exits)
Distinguishing between exiting a service and transferring to another provider	Feasible	Often not reported, difficult to transcribe
Estimating (relative) size of population outside each care element	Feasible	Not feasible with clinic-based data alone