What impact do questionnaire length and monetary incentives have on mailed health psychology survey response?

Abstract

ObjectivesResponse rates to health‐related surveys are declining. This study tested two strategies to improve the response rate to a health psychology survey mailed through English general practices: (1) sending a shortened questionnaire and (2) offering a monetary incentive to return a completed questionnaire.DesignRandomized controlled trial.MethodsAdults (n = 4,241) aged 45–59 years, from four General Practices in South‐East England, were mailed a survey on attitudes towards bowel cancer screening. Using a 2 × 4 factorial design, participants were randomized to receive a ‘short’ (four A4 pages) or a ‘long’ (seven A4 pages) questionnaire, and one of four monetary incentives to return a completed questionnaire – (1) no monetary incentive, (2) £2.50 shop voucher, (3) £5.00 shop voucher, and (4) inclusion in a £250 shop voucher prize draw. Age, gender, and area‐level deprivation were obtained from the General Practices.ResultsThe overall response rate was 41% (n = 1,589). Response to the ‘short’ questionnaire (42%) was not significantly different from the ‘long’ questionnaire (40%). The £2.50 incentive (43%) significantly improved response rates in univariate analyses, and remained significant after controlling for age, gender, area‐level deprivation, and questionnaire length. The £5.00 (42%) and £250 prize draw (41%) incentives had no significant impact on response rates compared to no incentive (38%).ConclusionsA small monetary incentive (£2.50) may slightly increase response to a mailed health psychology survey. The length of the questionnaire (four pages vs. seven pages) did not influence response. Although frequently used, entry into a prize draw did not increase response. Achieving representative samples remains a challenge for health psychology. Statement of contribution What is already known on this subject Response rates to mailed questionnaires continue to decline, threatening the representativeness of data.Prize draw incentives are frequently used but there is little evidence to support their efficacy.Research on interactions between incentives, questionnaire length, and demographics is lacking. What does this study add Contrary to previous findings, questionnaire length did not influence response rate.A £2.50 incentive increased response, while incentives of £5.00 and a £250 prize draw did not.Achieving representative samples to questionnaires remains a challenge for health psychology.

Beliefs of UK Transplant Recipients about Living Kidney Donation and Transplantation: Findings from a Multicentre Questionnaire-Based Case–Control Study

“…The proportion of missing data was small. However, the study has limitations: (i) Although our response rate was reasonable for an unincentivized postal survey, and compares to the response rate of other postal surveys in the UK [41,42] and that of previous a previous European transplant survey [43], there is a risk of self-selection bias. We have reported in our results that our population appeared population representative (Table S2).…”

Links between self-injury and suicidality in autism

“…The generalizability of the present study is further limited by biases that may have been introduced by our sampling method: sending out email invitations, advertising our study in person at local support groups (this accrued the smallest return), and advertising it on social media. A number of studies have documented that women are generally more likely than men to engage with online surveys [82][83][84], and our disproportionate ratio of females to males would seem consistent with this observation, despite its incongruence with the elevated ratio of males to females diagnosed with autism [85,86]. Notably, studies concerning mental health in non-autistic people have linked the lower up-take by men to the greater stigma that men experience around discussing and seeking help for mental ill-health [87][88][89][90][91][92].…”

Unconditional and conditional monetary incentives to increase response to mailed questionnaires: A randomized controlled study within a trial (SWAT)

“…The relationship between monetary incentive and response to mailed questionnaires may be influenced by the value of the incentive and mediated by participant characteristics . For example, UK participants living in more affluent areas were significantly more likely than those in areas of greater deprivation to respond to a mailed health behaviour questionnaire with a conditional £5 incentive but not with a conditional £2.50 incentive . It is therefore useful to explore whether groups from areas of greater deprivation respond differently to those in affluent areas to more proactive recruitment and data collection methods such as the offer of unconditional monetary incentives.…”

“…Individuals from the most deprived socio‐economic groups can be more difficult to engage in mailed questionnaire research even when monetary incentives are offered. A UK study found a statistically significantly lower response rate in the most deprived quartile (39%) compared with the least deprived quartile (52%) …”