Introductory postcards: do they increase response rate in a telephone survey of older persons?
One of the regular annoyances of contemporary life is the unsolicited telephone call requesting participation in a survey. The survey is generally presented as a disinterested service to the community, but in fact is usually part of a sales technique for anything from double glazing to life insurance. As telephone surveys are a useful tool for researchers working in the field of public health, possible methods of establishing the legitimacy of the survey, and hence it is hoped reducing the refusal rate, are of considerable interest. In this Australian study, 208 people aged 60 and over were sent a postcard before telephone contact was made, while a control group of 140 were not. The proportion of older people agreeing to participate was higher in the former group. The authors argue that an introductory postcard provides a cost-effective method of increasing participation rates, and therefore of minimising potential biases.