Comparability of Internet and telephone data in a survey on the respiratory health of children.

BACKGROUND: Mixing survey administration modes has generated concern about the comparability of responses between modes. OBJECTIVE: To explore the differences in respondent profiles, and responses between Internet and telephone questionnaires in a survey on respiratory diseases. METHODS: The data were generated from a mixed Internet and telephone survey of respiratory diseases among children in Montreal (Quebec), in 2006. Comparison of 12 selected questions was performed after standardization for respondent education and income. Stratification of analysis on education and income categories was also performed for the questions with significantly divergent responses. RESULTS: Six questions showed significant differences in responses between modes after standardization. The largest differences among the closed-ended questions were observed for highly prevalent symptoms, dry cough during the night (difference of 9% for positive answer [P<0.01]) and symptoms of allergic rhinitis (difference of 7% for positive answer [P<0.01]). A large discrepancy was also found in the multiple choice question and with an open-ended response (ie, free answer). For the three potentially sensitive questions, a desirability bias was probably present in one question on smoking habits (difference of 2.6 % for positive answer [P<0.05]). CONCLUSION: The differences observed between Internet and telephone responses to selected questions were not completely explained by socioeconomic disparities among the respondents. In a mixed-mode survey (Internet and telephone), caution should be used when formulating sensitive, complex, open-ended and long-ended questions, and those related to highly prevalent and nonspecific symptoms.

Prevalence of pathological gambling in Quebec in 2002.

OBJECTIVE: To assess gambling behaviours and the problems associated with pathological gambling among the adult population of Quebec in 2002. METHOD: In Phase 1 of this 2-phase study, a total sample of 8842 adults was assessed. We used the South Oaks Gambling Screen (SOGS), adapted for telephone interview, to assess one-half of the sample; the other one-half was evaluated with the Canadian Problem Gambling Index (CPGI). In the study's second phase, we compared the classifications obtained from these screening instruments with classifications obtained by a psychologist using a semistructured clinical telephone interview. RESULTS: The results indicate that the prevalence of pathological gambling in 2002 (at which time 0.8% of the adult population were classified as probable pathological gamblers) did not differ from the proportion obtained in 1996 (1.0%), despite the significant decrease in gambling participation in 2002 (81% vs 90% in 1996). The most popular gambling activities were buying lottery tickets (68%), participating in fundraising draws (40%), gambling in casinos (18%), playing cards with family or with friends (10%), playing bingo (9%), and playing video lotteries (8%). The findings obtained from the SOGS and the CPGI revealed that the 2 instruments perform similarly when identifying pathological gambling prevalence. However, the results of the semistructured clinical telephone interviews differed from the results obtained with the screening instruments: 82% of the gamblers initially identified as probable pathological gamblers by the SOGS or the CPGI were not confirmed by a clinical interview. CONCLUSION: The discrepancy between the results of the screening questionnaires and the clinical evaluation is significant, and this difference needs to be addressed before further cross-sectional or longitudinal studies are conducted.