Box 1. Risk analysis

Failure Mode and Effects Analysis (FMEA) or Hazard Analysis and Critical Control Points (HACCP) are two examples of risk analysis tools to identify potential weaknesses in a process. Procedures for conducting FMEA were described in US Armed Forces Military Procedures document MIL-P-1629 in 1949. During the 1970s, use of FMEA and related techniques spread to other industries. HACCP is the adaptation of the FMEA to the food industry

The aim of these analyses is to identify all possible failures or hazards in each part of a system, during its design stage, in order to ensure that they can be prevented from occurring in the first place. Applied to an epidemiological study, this can be done by systematically questioning, for each step in the survey process (e.g. study preparation, data collection, data analysis, etc.): what can go wrong (failure modes in FMEA, hazards in HACCP)? How can this be prevented? How can we check that we are doing things right (detection in FMEA)? How can we fix things if they go wrong (mitigation in FMEA and corrective actions in HACCP)?