  The health and demographic surveillance system (HDSS) is an old method for
intensively monitoring a population to assess the effects of healthcare or
other population-level interventions - often clinical trials. The strengths of
HDSS include very detailed descriptions of whole populations with frequent
updates. This often provides long time series of accurate population and health
indicators for the HDSS study population. The primary weakness of HDSS is that
the data describe only the HDSS study population and cannot be generalized
beyond that.
  The 2030 agenda is the ecosystem of activities - many including
population-level monitoring - that relate to the United Nations (UN)
Sustainable Development Goals (SDG). With respect to the 2030 agenda, HDSS can
contribute by: continuing to conduct cause-and-effect studies; contributing to
data triangulation or amalgamation initiatives; characterizing the bias in and
calibrating 'big data'; and contributing more to the rapid training of
data-oriented professionals, especially in the population and health fields.
