Effectiveness of various mailing strategies among nonrespondents in a prospective cohort study. Increasing response rates in physicians' mail surveys: an experimental study. Controlled trial of the effect of length, incentives, and follow-up techniques on response to a mailed questionnaire. A randomized trial of the impact of telephone and recorded delivery reminders on the response rate to research questionnaires. Effects of mailing strategies on response rate, response time, and cost in a questionnaire study among nurses. Increasing response to mailed questionnaires by including a pencil/pen. No increase in response rate by adding a web response option to a postal population survey: a randomized trial. Primer postcard improves postal survey response rates. Initial nonresponders had an increased response rate after repeated questionnaire mailings.
Measures of association in prospective studies can be distorted by incomplete follow-up. Various mailing strategies were used to contact 12,233 cohort members of the Health Professionals Follow-up Study who had not responded to three successive bulk-rate mailings. Response rates were highest, 79.5% overall, from participants who were sent a certified mailing in phase 1 (63.2%), followed by a repeat certified mailing to nonrespondents (44.3%). Although altering the physical appearance of the envelope and using other postal rates were tested, certified mail was the most effective approach for reaching study members who were nonrespondents to a mailed questionnaire. It is becoming increasingly difficult to obtain high response rates in physicians' mail surveys. In 1983-84, we tested the effectiveness of two techniques among 604 Quebec physicians who had not responded to an initial letter. A handwritten thank you note at the bottom of the letter accompanying the questionnaire and a more personalized mailout package increased response rates by 40.7 per cent and 53.1 per cent, respectively, compared to control groups. Mailed questionnaires are an economical method of data collection for epidemiologic studies, but response tends to be lower than for telephone or personal interviews. As part of a follow-up study of volunteers who provided a brief health history and blood sample for a blood specimen bank in 1989, the authors conducted a controlled trial of the effect of length, incentives, and follow-up techniques on response to a mailed questionnaire. Interventions tested included variations on length of the questionnaire, effect of a monetary incentive, and effect of a postcard reminder versus a letter accompanied by a second questionnaire. Response was similar for the short (16-item, 4-page) and long (76-item, 16-page) questionnaire groups. The non-monetary [corrected] incentive did not improve the frequency of response. The second mailing of a questionnaire was significantly better than a postcard reminder in improving responses (23% vs. 10%). It is important to systematically test marketing principles to determine which techniques are effective in increasing response to mailed questionnaires for epidemiologic studies. A range of factors have been shown to affect the response rate to mailed questionnaires, but particular strategies to improve patients' response in trials conducted in general practice require further study.
                Non-responders in a larger trial were randomized to receive a telephone or recorded delivery reminder on the third contact. The cost of administration of each method was estimated.
                Significantly more patients returned completed questionnaires when sent questionnaires by recorded delivery, although the cost per patient contacted was nearly three times more than for contact by telephone.
                Our study indicates that sending reminders by recorded delivery, although more expensive, is more effective than telephone reminders for recruiting patients to a study in general practice using research questionnaires. We conducted a pilot study to determine the most efficient mailing strategy for a postal questionnaire study among nurses in Ontario, Canada. Five mailing strategies involving types of stamps on the return envelopes were considered: no stamp, business-reply stamp, metered stamp, small regular stamp, and large commemorative stamp. We found that paper stamps, especially large commemorative stamps, on return envelopes increased the response rate and reduced the response time, as compared with other mailing strategies. Business-reply stamps had the lowest cost per response received and a low total cost. Nonmonetary incentives lead to small increases in response rates to mailed questionnaires. However, inclusion of a pen or pencil, which may be a facilitating factor as well as a reward, has not been shown to improve response to health surveys in prior trials. In 2001 and 2002, the authors conducted two US trials in which a study-logo pen or pencil was randomly included in a second questionnaire mailed to nonresponders to a first mailing. In the first study, of 10,686 nonresponders to a cohort recruitment mailing, response to the second mailing was 55% with inclusion of a pen versus 40% without one (p < 0.001). In the second study, of 141 nonresponders to a pilot follow-up survey conducted 2 years after entry into a cohort, response was 43% with inclusion of a pencil versus 24% without one (p = 0.02). This 15-19 percentage point increase for mailing 2 translated to a 5-6 percentage point increase after the two mailings combined. In a simulated study of three mailings based on these studies, the overall response rate increased by 4 percentage points at no added cost through inclusion of a pencil in the second mailing. The additional cost of the pencil was compensated for by the reduced number of nonrespondents sent packets at the third mailing. This study supports including a study-logo pen or pencil in a second questionnaire mailing to nonrespondents as a cost-effective method of increasing response rates. There is substantial interest in use of the Internet for surveys, but there have been few health-oriented, large, randomized trials of general population surveys on the Internet. It is unclear whether providing the option to respond via Internet increases the response rate, and to what degree the results will differ.
                The aim of the study was to evaluate changes in response rate and outcomes in a postal respiratory health survey by adding an optional Web response alternative.
                This was a randomized trial of a random sample of 4213 permanent residents of Norway, aged 20-40 years. Participants were randomized into a traditional survey arm, where they were asked to return the survey by mail, and an arm where they were also offered the option to respond via a Web form.
                A total of 1928/4213 subjects responded, a response rate of 45.8% across both arms. The total response rate was 44.8% (944/2105) in the postal plus optional Internet response arm and 46.7% (984/2108) in the usual postal survey arm, with no statistically significant difference between the randomized groups (P = .24). In the optional Internet arm, 8.3% (175/2105) of the sample responded using the Internet and 36.5% (769/2105) responded by post. Thus, Internet response was chosen by 18.5% (175/944) of those who replied in the optional Internet arm. In the multivariate analysis, Internet response was associated with being male, frequency and type of Internet access (home users more likely to respond by Internet than work users), and smoking habit, with current smokers being more likely to be Internet responders. 57% preferred postal response (1102/1928), 38% preferred Internet response (733/1928), and 3% preferred telephone interview (54/1928), with no difference between randomization arms (P = .56). But among those who indicated that they preferred the Internet response and who were randomized to the optional Internet arm, only 47% actually chose the Internet response. Asthma prevalence was higher among participants choosing the Internet response mode (16.7% vs 12.4%).
                We failed to increase survey response rates by adding an optional Internet response. Asthma diagnosis was higher in the Internet response group, suggesting nonresponse bias. Method comparison studies should be carried out before Internet studies are accepted in new populations or new subject matters. This study measures the effect of an intervention to improve mailed survey response rates.
                A randomised controlled trial of a 'primer' postcard was performed as part of a large survey in Victoria in 1997. Prior to the survey mailout, half the sample of 800 general practitioners supplied by the Health Insurance Commission was sent, at random, a primer card to request prompt return of the survey.
                The intervention resulted in a more rapid return of the survey and improved overall response rates from 60% to 66%. The increased cost per returned survey (40 cents) was largely offset by fewer non-responders requiring follow-up.
                A primer postcard is a time and cost-efficient method to increase response rates in general practitioner surveys.
                Public health researchers should consider implementing this intervention to improve response rates to postal surveys. Reports of other response maximising strategies should report the cost per returned survey to allow better comparison. There is a growing evidence base on methods to improve response rates in surveys among patients. This study aimed to determine the additional effect of two intensive follow-up procedures compared to a simple follow-up procedure.
                Randomized controlled trial that compared repeated mailing of the questionnaire and a request to explain nonparticipation with a simple reminder card. The study population comprised 955 elderly adults registered with 26 general practitioners in The Netherlands.
                A total of 530 adults (56%) returned the questionnaire within 3 weeks and a total of 640 (67%) after follow-up. Repeated mailing of the questionnaire had additional effect compared to the simple reminder card in the group of initial nonresponders (relative risk=1.60, 95% confidence interval: 1.11-2.31), but not regarding the overall response rate. A request to explain nonparticipation did not have additional effect.
                Repeated mailing of the questionnaire increased the effectiveness of follow-up among initial nonresponders.
Health researchers using postal and electronic questionnaires can increase response using the strategies shown to be effective in this systematic review.