[Clinical single case study (n-of-1 trial)]

Area of Science:

• Clinical Medicine
• Medical Research Methodology

Background:

• N-of-1 trials, a type of single-case randomized trial, offer a method for optimizing individualized treatment.
• Evaluating treatment efficacy in complex cases, such as post-transplant complications or undiagnosed symptomatic conditions, presents clinical challenges.

Observation:

• A patient with bronchiolitis obliterans post-lung transplantation showed improvement with inhaled steroids.
• A second patient with symptoms suggestive of HIV-associated Addison's disease improved with cortisone, despite normal adrenocortical function.

Findings:

• The N-of-1 trial confirmed the beneficial effect of inhaled steroids in the first patient.
• The N-of-1 trial demonstrated the inefficacy of cortisone for the second patient, despite initial symptomatic improvement.

Implications:

• N-of-1 trials are a practical tool for physicians to definitively assess treatment effectiveness in individual patients.
• This methodology supports evidence-based decision-making for personalized medicine and complex clinical scenarios.