Bmc Health Serv Res
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Bmc Health Serv Res · Nov 2004
Randomized Controlled Trial Clinical TrialIncreasing response to a postal survey of sedentary patients - a randomised controlled trial [ISRCTN45665423].
A systematic review identified a range of methods, which can influence response rates. However, analysis specific to a healthcare setting, and in particular, involving people expected to be poor responders, was missing, We examined the effect of pre-warning letters on response rates to a postal survey of sedentary patients whom we expected a low rate of response. ⋯ The relatively low cost method of sending a pre-warning letter had a modest impact on increasing response rates to a postal questionnaire sent to a group of patients for whom a low response rate was anticipated. Investigators should consider incorporating this simple intervention when conducting postal surveys, to reduce the potential for nonresponse bias and to increase the study power. Methods other than postal surveys may be needed however when a low response rate to postal surveys is likely.
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Bmc Health Serv Res · Nov 2004
Randomized Controlled Trial Clinical TrialA randomised controlled trial to determine the effect on response of including a lottery incentive in health surveys [ISRCTN32203485].
Postal questionnaires are an economical and simple method of data collection for research purposes but are subject to non-response bias. Several studies have explored the effect of monetary and non-monetary incentives on response. Recent meta-analyses conclude that financial incentives are an effective way of increasing response rates. However, large surveys rarely have the resources to reward individual participants. Three previous papers report on the effectiveness of lottery incentives with contradictory results. This study aimed to determine the effect of including a lottery-style incentive on response rates to a postal health survey. ⋯ This RCT, using a large community based sample, found that the offer of entry into a lottery style draw for pound 100 of High Street vouchers has no effect on response rates to a postal health questionnaire.