FACE-TO-FACE HOUSEHOLD INTERVIEWS VERSUS TELEPHONE INTERVIEWS FOR HEALTH SURVEYS

The purpose of this study was to compare response distributions in hea lth surveys for two interview modes: face-to-face household interviews and telephone interviews. There were two samples of the Perth metropo litan general population aged 16 to 69 years: a face-to-face household sample (n = 1000) and a telephone sample (n = 222), The samples were generated by probability-based methods commonly used by commercial mar ket research organisations. The surveys occurred in August-September 1 992 as part of a larger statewide survey component of a three-year eva luation of the Western Australian Health Promotion Foundation. Respond ents were drawn from a two-stage cluster sample based on private dwell ings for personal interviews, and from randomly selected listed and un listed private numbers for telephone interviews, Although the samples did not differ significantly on a number of variables, the telephone s ample was significantly higher in residential social status; there was significantly lower reporting of smoking and lower unsafe alcohol con sumption in the telephone sample; significantly higher proportions of the telephone sample were in Prochaska's 'action' stage of change for several health hehaviours; and there was significantly greater recall of health messages in the telephone sample. Health researchers should treat comparisons between different survey modes with caution, and sho uld be aware that campaign evaluations using telephoner surveys and ho usehold surveys may yield substantially different results.