Skip to main content
. Author manuscript; available in PMC: 2013 Sep 1.
Published in final edited form as: Contemp Clin Trials. 2012 Jul 5;33(5):942–948. doi: 10.1016/j.cct.2012.07.004

Fig. 3.

Fig. 3

Relationship between ad renewal and responses to the ad. (A) Response rate per ad renewal. The distribution of the response rate per ad renewal, defined as the number of responses attributed to the latest renewal of the study advertisement, was examined. (B) Effect of increasing time since ad renewal on daily ad response rate. The relationship between the response rate per day and the number of days from latest ad renewal was summarized by mean and standard error of the mean. (C) Effect of month of ad renewal on ad response rate. The relationship between the response rate per ad renewal and the month of placement of the ad renewal was examined. (D) Workload associated with ad placement. The burden of work resulting from ad renewals was assessed by examining the number of work days on which one or more ad responses were received. The majority of work days were associated with three or fewer responses.