Comparison of three inducement techniques to improve compliance in a health survey conducted by telephone.

The use of telephone interviews for epidemiologic and public health studies has increased in recent years. Since telephone surveys are susceptible to lower response rates than personal interviews, several attempts have been reported to increase respondents' compliance using various precontact procedures. This investigation evaluates the comparative effectiveness of three techniques to enhance compliance with a relatively long telephone interview on epidemiologic topics. The theoretical and practical applications in the domain of telephone surveys of two techniques, the foot-in-the-door and the low ball, commonly considered nonpressure techniques, are discussed. A newly suggested, combined compliance procedure is also introduced and tested. Results show that compliance was greater for the new method when compared with each of the other two methods. Moreover, each of the three methods outperformed a control condition. The theoretical models developed to devise and explain the new techniques received empirical support in a public health survey employing 335 adult residents of Tel Aviv, Israel, in May 1988.