The tactics of large randomized trials.

Single-center studies and small randomized controlled trials often provide contradictory or inconclusive results. In contrast, large randomized controlled trials are designed to definitively answer a relevant and practice-changing research question. These studies rely on large sample sizes to gain adequate precision of the results and substantial funding to support the research infrastructure necessary to minimize bias. Tactics for successfully completing a large randomized controlled trial are outlined with examples from recent orthopaedic trials.