Is the Perfect the Enemy of the Good?: Using the Data You Have

This chapter offers instructions on how to find the data needed for a particular public health improvement program. The chapter starts by defining two systems of data collection: primary and secondary. However, it is important to remember that all data has limitations. There is no such thing as perfect data. The use of primary data in practice or policy decision-making is often constrained by resources and time, as collecting robust data typically takes years. Although secondary data poses limits, such that it might be data not collected specifically for a particular health question, or not being representative of the population of interest, or perhaps there is a lag in data availability. However, the chapter concludes, things can always be improved even if perfection is never reached.