Comparison is the core of all scientific explanations. In the field of public health, comparative evaluation facilitates the process of setting benchmarks, developing guidelines, and exchanging good and best practices. And through comparative evaluation, both between and within countries, we can produce scientific knowledge about the causes of ill-health and consequently develop more effective methods to cure disease, care for the sick and promote health. Comparative health research enables us to explore the similarities and differences in a given domain, and helps us to improve the population’s health status and the functioning of health systems. This knowledge can also be used to substantiate and strengthen argumentation in debates on health policy.

What to compare?

As public health professionals we can compare a large variety of phenomena, indicators and constructs. We can compare over time, between geographical areas, between populations within a society, between countries and between cultures. The following list provides an exemplary overview of topics that could be subjected to a comparative analysis:

  • Health status
  • Health behaviour
  • Health attitudes
  • Health organizations
  • Health systems
  • Health treatments
  • Health policies and reforms
  • Health services
  • Health interventions


Opportunities and pitfalls of cross-country comparisons

When adopting an evaluative international perspective to public health, one quickly touches upon the domain of cross-country comparisons. In the introduction section of this page we already elaborated on the general advantages and opportunities of comparative evaluation in the field of public health. But there are also pitfalls and disadvantages that have to be considered.

Opportunities and advantages of international comparative evaluations in public health:

  • Useful for appraising the potential effects of various policy options as they are applied in other countries
  • Government empowerment: it provides insights on what steps a government could take
  • It provides alternative ways of interpreting and approaching a certain problem
  • It provides insights on how institutional structures shape and implement certain policies


Pitfalls and disadvantages of international comparative evaluations in public health:

  • Language and interpretation differences between countries/cultures
  • Sampling differences and difficulties (sample comparability for instance)
  • Discrepancies in research methodology and data collection procedures
  • Discrepancies in the definition of concepts, indicators and variables
  • Difficulties in deciding to what extent data is comparable
  • Cross-cultural factors and different societal contexts
  • Legislative issues and bureaucratic difficulties


Validity of comparisons

Quite frequently there is too much variation in research designs and data collection procedures to ensure valid comparability of data between countries. This is especially the case when conducting a secondary analysis (this means that the we use recycled data; the data was initially gathered for another purpose). In these cases the validity of the data is often not guaranteed, as we had no control ourselves over the data collection process. When we gather the data ourselves – and specifically for the study we want to conduct – we can conduct a primary analysis of the data. This way, we can build in quality assurance and incorporate ways of ensuring validity and reliability of our findings.

Still, performing a secondary analysis is generally more convenient, faster and cheaper than a primary analysis. It also allows us to include a much larger sample of participants. There are several big international organisations and supranational institutions that coordinate the monitoring of solid and trustworthy country-level data. This data is being incorporated in multiple big public health databases. The European Union tries to harmonise and standardise data collection procedures in the Member States, and  strives for the usage of common definitions and indicators across Europe.