Differential effectiveness of telephone prompts by medical and nonmedical staff in increasing survey response rates: A randomised trial

We conducted a randomised trial to determine the differential effectiveness of a telephone prompt by a medical researcher compared with a nonmedical research assistant in improving response rates of general practitioners to a survey and to compare personnel costs. A national random sample of Australian general practitioners was allocated randomly to two intervention groups. In advance of a self-administered questionnaire, Group A (n = 184) received a telephone prompt by a medical researcher and Group B (n = 189) a prompt by an experienced nonmedical research assistant. Other aspects of survey administration were identical for both groups. The five-month cumulative response rate obtained by the medical researcher (81 per cent) was not significantly different from that of 72 per cent obtained by the research assistant (chi(2) = 3.3, 1 df, P = 0.07). For Group A, 279 telephone calls, consuming 23 hours 15 minutes, were made. Group B required more calls (384) and more time (32 hours). Using the relevant award pay scales, the estimated personnel costs for each group were $631 and $601 respectively. We conclude that an experienced nonmedical research assistant is as effective as a medical practitioner in administering telephone prompts to enhance survey response rates, although savings are not necessarily made.