Department of Clinical and Biomedical Sciences; Barwon Health, The University of Melbourne, Geelong, Australia.
BMC Med Res Methodol. 2009 Nov 25;9:78. doi: 10.1186/1471-2288-9-78.
Randomised, placebo-controlled trials are needed to provide evidence demonstrating safe, effective interventions that reduce falls and fractures in the elderly. The quality of a clinical trial is dependent on successful recruitment of the target participant group. This paper documents the successes and failures of recruiting over 2,000 women aged at least 70 years and at higher risk of falls or fractures onto a placebo-controlled trial of six years duration. The characteristics of study participants at baseline are also described for this study.
The Vital D Study recruited older women identified at high risk of fracture through the use of an eligibility algorithm, adapted from identified risk factors for hip fracture. Participants were randomised to orally receive either 500,000 IU vitamin D3 (cholecalciferol) or placebo every autumn for five consecutive years. A variety of recruitment strategies were employed to attract potential participants.
Of the 2,317 participants randomised onto the study, 74% (n = 1716/2317) were consented onto the study in the last five months of recruiting. This was largely due to the success of a targeted mail-out. Prior to this only 541 women were consented in the 18 months of recruiting. A total of 70% of all participants were recruited as a result of targeted mail-out. The response rate from the letters increased from 2 to 7% following revision of the material by a public relations company. Participant demographic or risk factor profile did not differ between those recruited by targeted mail-outs compared with other methods.
The most successful recruitment strategy was the targeted mail-out and the response rate was no higher in the local region where the study had extensive exposure through other recruiting strategies. The strategies that were labour-intensive and did not result in successful recruitment include the activities directed towards the GP medical centres. Comprehensive recruitment programs employ overlapping strategies simultaneously with ongoing assessment of recruitment rates. In our experience, and others direct mail-outs work best although rights to privacy must be respected.
ISRCTN83409867 and ACTR12605000658617.
需要进行随机、安慰剂对照试验，以提供证据证明安全有效的干预措施可减少老年人的跌倒和骨折。临床试验的质量取决于目标参与者群体的成功招募。本文记录了一项为期六年的安慰剂对照试验，该试验招募了 2000 多名年龄至少 70 岁且有更高跌倒或骨折风险的女性，记录了招募过程中的成功和失败。还描述了研究参与者在基线时的特征。
Vital D 研究通过使用从髋部骨折风险因素中确定的资格算法，招募了有较高骨折风险的老年女性。参与者被随机分为两组，分别口服 500000IU 维生素 D3（胆钙化醇）或安慰剂，每年一次，连续五年。采用了多种招募策略来吸引潜在参与者。
在随机分配到研究的 2317 名参与者中，74%（n=1716/2317）在招募的最后五个月同意参加研究。这主要是由于有针对性的邮寄活动的成功。在此之前，在 18 个月的招募中只有 541 名女性同意参加。由于有针对性的邮寄活动，共有 70%的参与者被招募。在一家公关公司修改材料后，信件的回复率从 2%提高到 7%。通过有针对性的邮寄活动招募的参与者与通过其他方法招募的参与者的人口统计学或风险因素特征没有差异。
最成功的招募策略是有针对性的邮寄活动，在研究通过其他招募策略广泛曝光的当地地区，回复率并没有更高。那些劳动强度大且未成功招募的策略包括针对全科医生医疗中心的活动。全面的招募计划同时采用重叠策略，并持续评估招募率。根据我们的经验和其他经验，直接邮寄效果最好，尽管必须尊重隐私权。
ISRCTN83409867 和 ACTR12605000658617。
