Epidemiology Question

Question

For the New Jersey case-control study, cases were identified by reviewing laboratory records from all clinical laboratories in the state. Forty-two cases were identified. Two controls were identified for each case through telephone calls to randomly selected households in the community. To be eligible for the study, controls could not have had loose stools during the previous 30 days. Investigators interviewed 30 case-patients and 60 controls by telephone using a standardized questionnaire that asked about possible exposures (including consumption of 17 fruits and 15 vegetables, water and soil exposures, and animal contact) during the period of interest. Case-patients and controls were similar with respect to age, sex, and level of education. Twenty-one (70%) of 30 case-patients and four (7%) of 60 controls had eaten raspberries. The odds ratio for eating raspberries was 32.7 (p-value <0.000001). No other exposures (including strawberries) were associated with illness.

Question 11: In your own words, interpret the results of the New Jersey case-control study.

Question 12: Would you alert the public of this possible public health threat? Defend your answer.

Answer 1

People who had eated rasperries had 32.7 times the odds of being a case compared to people who did not eat raspberries.

As demographic characteristics (age, sex and education) are held constant, the increase in odds is still statistically significant, hence the public should be alerted and the public health agency should conduct further prospective studies and investigations on the potential likelihood of contaminated raspberries.