[Telephone versus face-to-face household interviews in the assessment of health behaviors and preventive practices].
OBJECTIVE
This study examines the influence of the interview method (telephone or face-to-face in households) on the assessment of health behaviors and preventive practices.


METHODS
The same questionnaire was completed by two independent samples of the population aged 18-64 years living in the municipality of Madrid. One sample (n = 1,391 subjects) completed the questionnaire by telephone interview and the other (n = 739) by face-to-face interview in households. The results of the two samples for 28 variables related to anthropometry, physical activity, food consumption, tobacco and alcohol use, preventive practices and injuries were compared.


RESULTS
The telephone sample had a higher rate of failed contact (31.8% vs. 22.2%) but a greater degree of cooperation than the sample for the face-to-face interview (83.0% vs. 74.0%). In total, 19 of the 28 variables showed a relative variation of less than 10% between the two surveys; the differences found were between 10 and 20% for eight variables and were higher than 20% for one variable. Differences were statistically significant for only four variables (sedentary leisure time, consumption of vegetables, giving up smoking and cholesterol measurement), with a relative variation of 6.1% (p < 0.01), 10% (p < 0.001), 36.7% (p < 0.01) and 8.6% (p < 0.01), respectively. The total cost of the telephone interview was half that of the face-to-face household interview.


CONCLUSIONS
The results of both surveys were very similar. Because of its lower cost, the telephone interview is a good option in public health research when data collection by interview is required.
Galán
Iñaki
I
Servicio de Epidemiología, Instituto de Salud Pública, Consejería de Sanidad de la Comunidad de Madrid, Madrid, Spain. inaki.galan@madrid.org
Rodríguez-Artalejo
Fernando
F
Zorrilla
Belén
B
D000293:Adolescent; D000328:Adult; D005260:Female; D015438:Health Behavior; D006293:Health Promotion; D006801:Humans; D007407:Interviews as Topic / Q000379:methods*; D008297:Male; D008875:Middle Aged; D013689:Telephone