Resource use and costs of investigator-sponsored randomized clinical trials in Switzerland, Germany, and the United Kingdom: a metaresearch study

Conducting high-quality randomized clinical trials (RCTs) is challenging and resource intensive. Funders and academic investigators depend on limited financial resources and, therefore, need empirical data for optimal budget planning. However, current literature lacks detailed empirical data on resource use and costs of investigator-sponsored RCTs. The aim of this study is to systematically collect cost data from investigator-sponsored RCTs from Switzerland, Germany, and the United Kingdom (UK). Principal investigators were asked to share their RCT cost and resource use data and enter it into an online case report form. We assessed cost patterns, cost drivers, and specific cost items, examined costs by study phase (planning-, conduct-, and finalization phase), compared planned with actual RCT costs, and explored differences in cost patterns across countries, medical fields, and intervention types. We included 93 RCTs which were initiated in Switzerland (n = 53; including eight conducted in low- and lower middle-income countries), Germany (n = 22), and the UK (n = 18). The median total trial cost in our RCT sample was $645,824 [interquartile range (IQR), $269,846–$1,577,924]. The median proportion of the total costs spent for planning phase was 27.5% [IQR, 20.6%–39.7%], for conduct phase 57.3% [IQR, 44.4%–66.3%], and for finalization phase 12.7% [IQR, 8.5%–19.3%] with little variation across countries. The items that contributed most to the total costs were protocol writing (7.2%; IQR 3.8%–10.6%), data management (5.0%; IQR 2.2%–8.1%) and follow-up (4.5%; IQR 2.3%–8.4%). Of the 66 RCTs with an available original budget, 46 (69.7%) exceeded the budget by over 50%. Use of routinely collected data to assess primary outcomes was independently associated with lower per patient- and lower total trial costs. Over a quarter of total trial costs were incurred in the planning phase, which is typically not fully funded. Two-thirds of RCTs exceeded their budget by more than 50%. Investigators and funders should consider empirical cost data to improve budgeting and funding practices. •Over a quarter (27.5%) of total trial costs were incurred in the trial planning phase.•Seventy percentage of RCTs exceeded their budget by more than 50%.•Key costs were protocol writing (7.2%), data management (5.0%), and follow-up (4.5%).•Factors associated with higher total cost included number of centers and longer duration.•Trials using routinely collected data for primary outcomes wer