Recruiting Phobic Research Subjects: METHODS

In: Anesthesia

23 Dec 2009


The recruitment goal was 180 subjects with specific phobia of dental injections according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). The initial expectations were not met. After 3 years, 108 subjects were enrolled and the goal revised downward to 144. Exclusion criteria were (1) obesity, (2) too young/old, (3) drug contraindications, (4) severe untreated depression or bipolar disorder, (6) unreliable jdid not appear for a screening twice), or (7) could not be contacted after repeated efforts. The 911 subjects described include those who responded to recruitment during 45 months of advertising and recruiting.

Advertising Strategy

Multiple methods were used simultaneously. Paid advertising, free publicity, and professional referrals were used. Success was reviewed in weekly meetings. The Institutional Review Board of the University of Washington reviewed the advertisements. viagra soft

Paid advertisements appeared on radio and in newspapers, buses, and on posters on the campus. Advertisements emphasized that participants would receive free therapy. To minimize calls from those only seeking money, the financial incentives were not mentioned in advertisements.

The radio advertisement was 1 minute long and was broadcast 7 times during 3 days on 1 station. It contained a description of the study, an offer of free therapy, and contact information. Information about the study was also delivered in public service announcements (PSAs) based on information from a medical news press release from the University. PSAs were broadcast at the initiation of recruitment and 2 years later. Both announcements were 30 seconds long and followed the style of the paid advertisement. For analyses, subjects recruited using both paid radio advertising and PSAs were combined.

Community newspapers, campus newspapers, major metropolitan daily newspapers and magazines, and free published weekly newspapers were employed. The campaign was continued throughout the recruitment period. To attract attention, the headline was varied. The advertisement was placed in both editorial and classified sections. It included a description of subjects needed, a mention about new therapy, an offer of free therapy, and contact information. Some newspapers also published a news story along with the advertisement. These stories included an interview with a subject from the market area, an interview with a researcher, general information about dental fear, and details about the study as well as contact information. The size of the advertisement varied from 1×2 inches and 2.5 X 5 inches. For analyses, subjects recruited from newspapers were combined.
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Posters were used to advertise at the University. The 8.5 x 11-inch posters were placed in approximately 100 locations. Posters included a brief explanation of the study, an offer of free therapy, and contact information. Each poster also included a cartoon to attract attention. The color and style of the posters were changed periodically. Posters included tear-off telephone reminder slips. Posters were changed frequently and continued throughout the recruitment period.

Posters were also used on bus interiors. These posters were similar to those used on campus but were larger (11 x 33 inch) and were placed on different routes in Seattle and its suburbs. A 3 X 4-inch tear-off pad with the study phone number was attached to each poster. Bus advertising was conducted 4 times during the recruitment process. The bus company guaranteed placement of the posters for 4 weeks, but posters often remained in place up to a year.

The University has a weekend Health Sciences Open House every other year. This study was presented at the Open House event in 1997, and a member of the research group was available to answer questions.

Three television stations contacted the researchers after seeing a university news release. The stations prepared stories 4 times. The 2-3-minute stories were each broadcast once in the morning in a news magazine program and 3 times during the local evening news. Each included an interview with a patient, a description of dental injection fear, and an interview with a researcher. The researchers were also contacted by a company selling television news stories through the Internet (Ivanhoe Broadcast News). The company has an Internet page where it advertises stories about medical breakthroughs. It published a cover story about the research. The story contained a brief explanation of the study, interviews with a subject and researcher, photographs of the study setting, and contact information.

Some recruits reported getting information about the study from a friend, relative, or from some other person. In these cases, the information about the study was delivered by word of mouth, and this was considered to be the primary method of the enrollment.

Professional Referrals

The dental and medical community was informed of the study by placing advertisements in professional association newsletters. The advertisement included an explanation of the study and the need for subjects. These advertisements were placed in the early stages of the study. The Dental Fears Research Clinic at the University also was a referral source. Subjects who had participated in other studies done in the Clinic were also informed about the study.
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A study coordinator was responsible for initial telephone screening and scheduling. The following information was collected during the initial screening: (1) name, (2) date, (3) telephone number and address, and (4) level of interest. Each caller was also asked to identify the source of his or her information about the study. Some subjects mentioned several sources. In that case, the first source each subject mentioned was considered the primary source. Following this, the study protocol and critical inclusion criteria were explained. Subjects interested in participating were sent a brochure and a questionnaire designed to characterize subjects. A 10-minute videotape explaining the study was also sent during the first year of recruitment. This was discontinued because of the costs (prospective subjects did not return the tapes) and the estimated benefits were considered low (eg, material in the video could be covered more succinctly over the phone).

Subjects who returned the questionnaire were contacted again and scheduled for screening. At the screening, the study was explained again and the consent form reviewed. Potential subjects were asked to sign the consent form. The screening appointment also included a medical history and an interview with a psychologist using the Structured Clinical Interview (SCID) for DSM-IV. A diagnosis of specific phobia for dental injections was made based on the SCID and interview. If prospective subjects were accepted and agreed to participate, they were enrolled. The enrolled subjects were randomized to study conditions, and each was asked to continue therapy until he/she was able to receive a dental injection at 2 consecutive appointments or withdrew. Subjects were paid $150 at completion. silagra 100


The original recruitment budget approved by the NIH study section was $17,000 ($94.44/subject). The budget was cut administratively by NIDCR to $12,805 ($71.14/subject). The cost estimate for the videotape was $2300. Therefore, the remaining budget was $10,505 ($58.36/subject). The direct cost of advertising using each method was recorded for each year over 45 months (January 1996-September 1999) and expressed as 1996 dollars using the Consumer Price Index for the Seattle-Tacoma area for the appropriate year as a deflator. Staff time spent designing advertisements and the costs of copying and mailing the questionnaires was not collected.

Data Analyses

Descriptive statistics were obtained using the Statistical Package for the Social Sciences. Contingency table analysis (x2, Pearson) was used to investigate the number of subjects in each phase of the recruitment process and the race, education level, and gender of subjects enrolled using different recruitment sources and methods. The Student t test was used to compare the average age of subjects enrolled by recruitment source and method. suhagra

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Blog invites submissions of review articles, reports on clinical techniques, case reports, conference summaries, and articles of opinion pertinent to the control of pain and anxiety in dentistry.