Original sentence: For example, public authorities may tend to fund preventive medicine studies to improve public health as a whole, while pharmaceutical companies fund studies intended to demonstrate the efficacy and safety of particular drugs.randomized double-blind placebo-controlled trials) may be expensive, so that funding sources play a role in what gets investigated
Edited sentence: For example, public authorities may tend to fund preventive medicine studies to improve public health, while pharmaceutical companies fund studies intended to demonstrate the efficacy and safety of particular drugs.large randomized double-blind placebo-controlled trials) are expensive, so that funding sources play a role in what gets investigated