Sep 24, 2001 (CIDRAP News) A recent study conducted in a hospital emergency department in London suggests that in the realm of food safety, there's no place like home. In the 6-month study, patients who were treated for a food-related illness were significantly more likely to have eaten away from home shortly before their illness than were patients treated for other conditions, according to a research letter published in The Lancet.
Peter Leman and David Strachan conducted their case-control study at St. Thomas's Hospital from August 1998 through January 1999. Case-patients included all patients treated for diseases known or believed to be foodborne or waterborne, and controls were all patients with any leg injury who underwent radiographic examination. All the subjects were asked to fill out a questionnaire about consumption of food prepared outside the home in the preceding 7 days. This included food served in all types of restaurants, by street vendors, or at parties (functions).
The researchers enrolled 112 case-patients and 172 controls. The two groups did not differ significantly in the rate of away-from-home eating in the 7 days before treatment (cases, 88.3%; controls, 85.55%; P=0.26). However, case-patients were significantly more likely to have eaten out on the day before or day of treatment than were the controls (cases, 75.9%; controls, 62.8%; odds ratio, 2.41; 95% confidence interval, 1.29-4.50; P=.006). The excess rate of disease due to eating out (population attributable risk fraction) was calculated at 37%.
The researchers gathered data on patients' exposure to food from different types of eating establishments for the whole 7 days, but did not determine where the patients had eaten on specific days. Controls were significantly more likely to have eaten in a restaurant or sandwich shop in the 7-day period, but the two groups did not differ significantly in their exposure to other eating venues (take-aways, canteens, street vendors, and functions). The authors suggest that the apparent protective effect of eating in restaurants and sandwich shops (as opposed to other away-from-home settings) may have been a healthy worker effect, ie, the controls may have had better general health, perhaps because of social class.
Leman P, Strachan D. A case-control study of food poisoning seen at an accident and emergency department. Lancet 2001;358(9279):387-8 [Abstract]