We are conducting a multicenter cross-sectional study in Italy, Romania, and Moldova to evaluate the association between potentially modifiable factors and amyotrophic lateral sclerosis (ALS). This inter-rater reliability analysis as an important part of this study aims to validate a lifestyle habits questionnaire.

We assembled an interviewer-administered questionnaire divided into three parts: the first (current consumption of alcoholic beverages) was validated in Italy, the second (smoking and drinking history) is part of the European Prospective Investigation into Cancer and Nutrition project, the third is an ad-hoc questionnaire collecting information about consumption of antioxidant-rich beverages and foods. The questionnaire was made in Italian and Romanian languages. Forty neurological patients from the Moldovan Center were interviewed by two blinded raters, with a randomized sequence. Intraclass correlation coefficient and Cohen’s kappa statistics were used to determine the level of agreement.

An almost perfect agreement (0.91–1) was obtained for the age at onset and cessation of smoking and drinking, patterns of smoking, number of cigarettes and for all dietary habits. Kappa values varied from 0.88 to 0.91 for the broad indicators of current consumption (yes/no) for each type of alcoholic beverage, whereas the agreement was only moderate (0.57) for the current alcohol intake (g/day), and fair for the daily quantity of beer and spirits (0.24).

The questionnaire is a reliable instrument to measure lifestyle pro-oxidant and antioxidant factors in ALS patients.