Non-inferiority designs comparing placebo to a proven therapy for childhood pneumonia in low-resource settings.

Background/aims: After a new treatment is recommended to be first-line treatment for a specific indication, outcome and population, it may be unethical to use placebo as a comparator in trials for that setting. Nevertheless, in specific circumstances, use of a placebo group might be warranted, for example, when it is believed that an active treatment may not be efficacious or cost-effective for a specific subpopulation. An example is antibiotic treatment for pneumonia, which may not be effective for many patients taking it due to the emergence of antibiotic-resistant strains or the high prevalence of viral and low prevalence of bacterial pneumonia. Methods: We explore the applicability of different design options in cases where the benefit of an established treatment is questioned, with particular emphasis on issues that arise in a low-resource setting. Using the example of a clinical trial comparing the effectiveness of placebo versus amoxicillin in treating children 2-59 months of age with fast breathing pneumonia in Lilongwe, Malawi, we discuss the pros and cons of superiority versus non-inferiority designs, an intent-to-treat versus as-treated analysis and the use and interpretation of one- versus two-sided confidence intervals. Results: We find that a non-inferiority design using an intent-to-treat analysis is the most appropriate design and analysis option. In addition, the presentation of one- versus two-sided confidence intervals can depend on the results but can maintain type I error. Conclusion: In the setting where the benefit of a previously established beneficial treatment is questioned, a non-inferiority design that includes placebo as the tested treatment option can be the most appropriate design option.