Cost-efficient higher-order crossover designs for two-treatment clinical trials

Introduction: To produce results from clinical trials that are statistically significant, researchers must enroll enough participants; however, it is difficult to recruit sufficient participants. The ADAPTABLE trial is a pragmatic randomized controlled trial designed to compare two aspirin doses in patients with cardiovascular disease. Methods: We used eligibility criteria set forth by the ADAPTABLE study protocol. We then put patients into two groups. Patients with email addresses were group one, and sent an email weekly. Patients without an email address were in group two, and a letter was mailed to their home address. Eligible patients who had a clinic appointment scheduled were also recruited approached in clinic. Most of these patients had already been stratified into the email or letter group, but there was the possibility that they had a new diagnosis and had not been contacted. All were given a link to the ADAPTABLE trial portal with an access code to enroll. An explanatory video about the study and electronic informed consent were on the trial website. Results: As shown in Table 1, four hundred and nine patients enrolled in our trial over a 10-month period. Three hundred and ninety-seven (97.06%) patients enrolled in the study via email. Letters were sent to 7,226 patients and four (0.98%) enrolled in the study. Eight (1.96%) of the patients who were approached in person enrolled in the study. The cost of email campaign was $1.44/patient and the cost per enrollment was the least expensive, at $95.71. In person enrollment cost $23.34/patient and the total cost per enrollment was $417.12. The letter recruitment cost $0.30/patient, however, the cost per enrollment was the highest, at $542.26. Conclusion: Email is an effective and economical way to recruit patients for clinical trials. Email allows researchers to contact more patients about proposed studies promptly and facilitates pragmatic research trials that achieve results in a timely and cost-efficient manner.

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Optimal and/or Efficient Two treatment Crossover Designs for Five Carryover Models

The International Journal of Biostatistics ◽

10.1515/ijb-2018-0001 ◽

2018 ◽

Vol 14 (2) ◽

Cited By ~ 1

Author(s):

Jigneshkumar Gondaliya ◽

Jyoti Divecha

Keyword(s):

Clinical Trials ◽

Computer Code ◽

Crossover Designs ◽

Carryover Effects ◽

Carryover Effect ◽

Test Treatment ◽

Exhaustive List ◽

Code Searches

Abstract Crossover designs robust to changes in carryover models are useful in clinical trials where the nature of carryover effects is not known in advance. The designs have been characterized for being optimal and efficient under no carryover-, traditional-, and, self and mixed carryover- models, however, ignoring the number of subjects, which has significant impact on both optimality and administrative convenience. In this article, adding two more practical models, the traditional, and, self and mixed carryover models having carryover effect only for the new or test treatment, a 5M algorithm is presented. The 5M algorithm based computer code searches all possible two treatment crossover designs under the five carryover models and list those which are optimal and /or efficient to all the five carryover models. The resultant exhaustive list consists of optimal and/or efficient crossover designs in two, three, and four periods, having 4 to 20 subjects of which 24 designs are new optimal for one of the established carryover models, and 34 designs are optimal for newly added models.

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Crossover designs for two-treatment clinical trials

Journal of Statistical Planning and Inference ◽

10.1016/s0378-3758(99)00185-8 ◽

2000 ◽

Vol 87 (1) ◽

pp. 125-134 ◽

Cited By ~ 18

Author(s):

K.C. Carriere ◽

Rong Huang

Keyword(s):

Clinical Trials ◽

Crossover Designs

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Impact of Recent Findings on Study Design of Future Autism Clinical Trials

CNS Spectrums ◽

10.1017/s109285290000835x ◽

2004 ◽

Vol 9 (1) ◽

pp. 49-56 ◽

Cited By ~ 18

Author(s):

Eric Hollander ◽

Ann Phillips ◽

Bryan H. King ◽

Donald Guthrie ◽

Michael G. Aman ◽

...

Keyword(s):

Clinical Trials ◽

Study Design ◽

Lessons Learned ◽

National Institutes Of Health ◽

Crossover Designs ◽

Autism Research ◽

Subject Selection ◽

Adult Autism ◽

Statistical Issues ◽

Multicenter Clinical Trials

ABSTRACTThere are specific challenges to studying the design of pharmacologic trials in child/adolescent and adult autism, such as subject stratification and parallel versus crossover designs. This article describes how optimal study design is influenced by subject selection and outcome measures chosen. Lessons learned in study design from the Research Units on Pediatric Psychopharmacology Autism Network trial with risperidone, Seaver Center trials with fluoxetine and valproate, Dartmouth trials with amantadine, and National Institutes of Health secretin trials are highlighted. The Internet System for Assessing Autistic Children system for managing multicenter clinical trials in autism and statistical issues in autism research are also described.

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Robust sequential crossover designs for clinical trials

Controlled Clinical Trials ◽

10.1016/0197-2456(91)90272-n ◽

1991 ◽

Vol 12 (5) ◽

pp. 694

Author(s):

Tom G. Filloon ◽

Michael P. Meredith

Keyword(s):

Clinical Trials ◽

Crossover Designs

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CONCEPTUAL DESIGN OF A SUPERCONDUCTING QUADRUPOLE WITH ELLIPTICAL ACCEPTANCE AND TUNABLE HIGHER ORDER MULTIPOLES

International Journal of Modern Physics A ◽

10.1142/s0217751x09044395 ◽

2009 ◽

Vol 24 (05) ◽

pp. 923-940

Author(s):

SHASHIKANT MANIKONDA ◽

JERRY NOLEN ◽

MARTIN BERZ ◽

KYOKO MAKINO

Keyword(s):

Conceptual Design ◽

Cross Section ◽

Differential Algebra ◽

Higher Order ◽

New Method ◽

Elliptic Cross Section ◽

Quadrupole Magnet ◽

Charged Particle Beams ◽

Elliptic Cross ◽

Cost Efficient

For charged particle beams that are wider in the dispersive plane compared to the transverse plane it is cost efficient to utilize magnets that accept beams with elliptic cross section. In this paper we presents the conceptual design of a quadrupole magnet with elliptic cross section and with tunable higher order multipoles. The design consists of 18 superconducting race-track coils placed on two hollow concentric rhombic prism support structures. To compute the magnetic field for the proposed design a new method of calculating 2D and 3D fields for the air core magnets based on differential algebra (DA) techniques is developed. We will present the new method and discuss its implementation of new numerical tools based on this method in the code COSY Infinity.

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