Field validity and spatial accuracy of the Food Standards Agency Food Hygiene Rating Scheme data for England

Background Since 2012, the Food Standards Agency have maintained records of all businesses selling food in the UK as part of their Food Hygiene Rating Scheme (FHRS). The study aimed to evaluate the validity and spatial accuracy of these publicly available data through a field audit. Methods A field audit was conducted to record all food premises present in 5 Lower Layer Super Output Areas (LSOAs) in the North East of England. LSOAs were purposively selected from the top and bottom quintiles of the Index of Multiple Deprivation and from urban and rural areas. The FHRS data validity against the field data was measured as Positive Predictive Values (PPV) and sensitivity. Spatial accuracy was evaluated via mean difference in straight line distances between the FHRS coordinates and the field coordinates. Results The PPV was 95%, with a sensitivity of 89%. The mean difference in the geographical coordinates of the field audit compared to the FHRS was 110 metres, and <100 metres for 77% of outlets. Conclusions The FHRS dataset is a useful dataset for surveillance of the food environment and evaluation of interventions of the food environment.