title: Sample size determination for clinical research.
abstract: Calculating the sample size is a most important determinant of statistical power of a study. A study with inadequate power, unless being conducted as a safety and feasibility study, is unethical. However, sample size calculation is not an exact science, and therefore it is important to make realistic and well researched assumptions before choosing an appropriate sample size accounting for dropouts and also including a plan for interim analyses during the study to amend the final sample size.
authors.affiliation: Department of Medical Statistics, London, UK.
authors.forename: Duolao
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Medical Statistics, London, UK.
authors.forename: Ameet
authors.initials: A
authors.lastname: Bakhai
authors.affiliation: Department of Orthopaedic and Trauma Surgery, Campus Biomedico University of Rome, Rome, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Del Buono
authors.affiliation: Centre for Sports and Exercise Medicine, Queen Mary University of London, Barts and The London School of Medicine and Dentistry, Mile End Hospital, London, UK ; Department of Physical and Rehabilitation Medicine, University of Salerno, Salerno, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Maffulli
keywords: randomized control trials; sample size; statistics