Patient Recruitment in Clinical Trials: Areas of Challenges and Success, a Practical Aspect at the Private Research Site

Enrolling in clinical trials could be time-sensitive and time-demanding tasks for the research site, especially if it is a private research organization compared to the research conducted at an academic or medical center. Every study differs in various aspects, such as phases, study indication, eligibility criteria, etc. In terms of meeting the enrollment deadline, typically, the study indication and availability of the patient’s population at the geographical area of the research site would decide if the trial could be time-consuming. Patient recruitment and retention are critical for the success of every clinical trial;however, worldwide, this area is facing tremendous pressure and challenges. Globally 55% of clinical trials terminated due to low recruitment, with an average enrollment success rate of 40% for Phase III and IV trials. Over 80% of clinical trial attempts fail to enroll, extending the study and adding new study sites. In the United States, more than 80% of clinical trials fail to achieve targeted patient enrollment, and 30% of study participants discontinue participation. This article reviewed various factors hindering clinical trial recruitment and retention and suggested strategies to make the research site successful.

A Novel Open C-shaped Molar Band for Orthodontic Applications： Mechanical Characterizations and Clinical Trials

To evaluate the retention properties of the novel ‘C＇-shaped molar bands at a laboratory level. Resin-modified glass ionomer cement（RMGIC） was used as a luting agent for the novel C-shaped molar band. The mechanical properties of the band were examined and the retention performance was characterized in the mesial, distal and vertical directions. A clinical trial was conducted using a spilt-mouth design on 50 patients. The novel C-shaped molar bands fit most molars without a repeated try-in process.The use of both nanoHA coating and RMGIC enhanced the tensile（8.00 ± 1.8 MPa） and shear strengths（27.17 ± 8.6 MPa） of the molar bands, leading to high retention in vertical, mesial and distal directions（ p 〈 0.001）. In clinical trials, the C-shaped molar bands had a failure rate（15%） comparable to that of traditional bands, and 93% of the failed bands demonstrated an adhesive remnant index score of 0, corroborating the observation that no luting agent residue remained on the tooth surface in most cases. The novel C-shaped molar bands appear to be a promising appliance that requires further clinical investigations, and may be used effectively in orthodontics.