Restaurant inspection frequency: The RestoFreq Study.

Objectives: Foodborne illness is an important contributor to morbidity and health system costs in Canada. Using number of critical hazards as a proxy for food safety, we sought to better understand how to improve food safety in restaurants. We compared the current standard of annual inspections to twice-yearly inspections among restaurants "at risk" for food safety infractions. These were restaurants that had three or more elevated-risk inspection ratings in the preceding 36 months.

Methods: We conducted a two-arm randomized controlled trial between November 2012 and October 2014. The intervention was twice-yearly routine restaurant inspection compared to standard once-yearly routine inspection. Included were all restaurants within Saskatoon Health Region that were assessed as "at risk", with 73 restaurants in the intervention arm and 78 in the control arm. Independent sample t-tests were conducted between groups to compare: i) average number of critical hazards per inspection; and ii) proportion of inspections resulting in a rating indicating an elevated hazard.

Results: Over time we noted statistically significant improvements across both study arms, in number of both critical food safety hazards (decreased by 61%) and elevated-risk inspection ratings (decreased by 45%) (p < 0.0001). We observed no significant differences between the two groups pre- or post-intervention.

Conclusion: Results suggest increasing the number of annual routine inspections in high-risk restaurants was not associated with a significant difference in measures of compliance with food safety regulations. Findings of this study do not provide evidence supporting increased frequency of restaurant inspection from annually to twice annually.