Gaceta Sanitaria (Dec 2004)
Comparación entre encuestas telefónicas y encuestas «cara a cara» domiciliarias en la estimación de hábitos de salud y prácticas preventivas Telephone versus face-to-face household interviews in the assessment of health behaviors and preventive practices
Abstract
Objetivo: En este estudio se examina la influencia del método de encuesta, telefónica y «cara a cara» domiciliaria, sobre la estimación de los factores de riesgo para la salud asociados al comportamiento y la realización de prácticas preventivas. Material y método: El mismo cuestionario fue administrado en 2 muestras independientes de población de 18-64 años residente en el municipio de Madrid. Una muestra (n = 1.391) realizó la entrevista telefónica y la otra (n = 739), la entrevista «cara a cara» domiciliaria. Se compararon los resultados de las 2 muestras para 28 variables relacionadas con la antropometría, la actividad física, el consumo de alimentos, el consumo de tabaco y alcohol, las prácticas preventivas y la accidentabilidad. Resultados: La muestra telefónica obtuvo una mayor tasa de no contactos (31,8 frente a 22,2%) pero un mayor grado de cooperación que la muestra con entrevista «cara a cara» (83 frente a 74%). En total, 19 de las 28 variables mostraron una variación relativa entre ambas encuestas 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. Material and method: 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.
