Comparison of three interview methods on response pattern to sensitive and non-sensitive questions

الملخص EN

Background : To get more precise responses when gathering information about sensitive topics such as drug use, it is important to use the most optimal method. Objectives : This study was carried out to address the impact of three interview methods (street-based, household, and telephone interviews) on response pattern to sensitive and non-sensitive questions in terms of participation, disclosure and discontinuing rates. Patients and Methods : We selected three culturally diverse main cities of Iran.

Then, we randomly selected 300 subjects, 100 for each type of interview, from each main city (899 in total).

For street-based interviews only pedestrians who were walking alone were recruited; for household interviews only one individual from each house were participated (3-4 houses in each alley were selected) ; and for telephone interviews we selected phone numbers using a random number list.

We asked five non-sensitive and five sensitive (in related to drug use and sexual contacts among their personal networks) questions. Results: In telephone and household interviews, relative to street-based interviews, participants were less likely to disclose alcohol and drug-related behaviors (Adjusted OR = 0.76 ; 95 % CI : 0.60- 0.97) and sexual behaviors among their network (Adjusted OR telephone / street-based = 0.64; 95 % CI : 0.39- 1.07 and Adjusted OR household / street-based = 0.56 ; 95 % CI : 0.33- 0.95).

We found that participants who were interviewed via telephone were more likely (Adjusted OR = 1.24) and those who were interviewed at home were less likely (Adjusted OR = 0.86) to report non-sensitive information comparing to participants who were interviewed at street; however, these findings were not statistically significant.

The largest participation rate and the least discontinuing rate were observed in household interviews.

Conclusions : It seems that the methods of interview have effects on response to both sensitive and non-sensitive questions.

We believe that in street-based interviews respondents may disclose more sensitive information than telephone and household interviews.