After implementation of letter grading for restaurant inspections, the rate of Salmonella infections decreased 5.3 percent per year in New York City versus the rest of New York state from 2011-2015, compared with the period before implementation, 2006-2010.

Posting restaurant inspection results as letter grades at the point of service coincides with a decline in Salmonella infections in New York City and warrants consideration for broader use.

Those are among the findings of a study by Melanie J. Firestone and Craig W. Hedberg, both of the Minnesota Integrated Food Safety Center of Excellence and the University of Minnesota School of Public Health, and which are both Minneapolis based. It is published in the December edition of CDC’s Emerging Infectious Diseases.

The authors report that rates of Salmonella infection in the United States have not changed over the past 20 years.

They say restaurants are a typical setting for Salmonella outbreaks and sporadic infections. “Few studies have examined the effect of posting letter grades for restaurant inspections on the incidence of foodborne illness. We compared Salmonella infection rates in New York, New York, USA (NYC), with those in the rest of New York state before and after implementation of a letter grade system for restaurant inspections in NYC. We calculated a segmented regression model for interrupted time series data.”

As of 2014, half of all food expenditures are occurring at restaurants and take-out venues; up from 33 percent in 1970. It means restaurants are ever more responsible for the 48 million Americans who become ill each year from foodborne illnesses along with the 128,000 hospitalizations and 3,000 deaths.

The study says restaurants are often the setting for foodborne illness with 60 percent of all foodborne illnesses outbreaks by 2015 associated with restaurants By 2015, 60 percent of foodborne illness outbreaks involved such commercial food establishments as restaurants.

“Food service establishments play a role in the epidemiology of Salmonella infections, says the study’s abstract. “Salmonella may contaminate a wide range of raw ingredients, infect food workers, survive on contaminated surfaces, and grow in improperly held food items. Nontyphoidal Salmonella infections are the second most common foodborne illness and the leading cause of foodborne illness hospitalizations and death.

It says reducing Salmonella infections is a Healthy People 2020 objective, yet rates have not substantially changed over the last 20 years.

The authors say the inspection of food service establishments to protect food safety is a core function of state and local health departments; the checks help to identify risk factors for foodborne illness, such as those associated with Salmonella transmission, and to correct them, thus protecting consumers and industry.

They report that New York does not have a statewide policy for reporting restaurant inspection results.

In 2005, the Department of Health and Mental Hygiene (DOHMH) in New York City, began using a point-scoring system for food service establishment inspections to weight violations to reflect risk factors for foodborne illness.

New York City began posting letter grade on restaurants in 2010, using categorical rankings of an A, B, or C, or grade pending, to improve restaurant food safety, increase transparency of inspection information, and reduce the risk for foodborne illness transmission in restaurants

The DOHMH required establishments to post a sign with the letter grade in its window so that consumers could see it before entering. Public disclosure programs like this one seek to provide information to consumers when and where they need it so they can make informed decisions about potential risks.

These consumer decisions encourage restaurant operators to improve and maintain sanitary standards, thus improving sanitary conditions in restaurants. The letter grade program has already been shown to lead to improvements in sterile conditions in NYC: 35 percent more restaurants earned A grades in the three years after grading, compared with the three prior years.

The authors say the value of posting restaurant inspection ratings at the point of service has been the subject of “considerable debate.”
However, they say few studies have looked at the impact of posting policies on the incidence of foodborne illness.

Two studies of a letter grade program in Los Angeles County, California, USA, showed a reduction in foodborne-illness hospitalizations. In NYC, a preliminary analysis of letter grading at 18 months suggested a decline in Salmonella infections. The goal of the Minnesota study was to compare the incidence of Salmonella infections in NYC with the incidence in the rest of the state before and after the implementation of posting letter grade placards at the point of service.

The study acknowledges that “overall, Salmonella infections declined in NYC and NYS between 1994 and 2015. Although NYS had declines in Salmonella infection rates after 2010, NYC saw declines greater than those in NYS. Inspection processes were largely unchanged in NYC with the implementation of the point scoring system in 2005 (15). The letter grade placard program begun in 2010 did not change the point scoring system but rather used the points to create a readily comprehensible ranking system accessible at the point of service

“Our analysis supports the hypothesis that having a point scoring system was not associated with declines in Salmonella infections but having a simple way to disclose the results of the inspection publicly was, the authors said.