Patients with posterior urethral valves (PUV) represent a cohort with wide variability in their clinical presentation. The management of these patients thus varies depending on the severity of pathology. Optimizing the clinical outcomes of individual patients with PUV is challenging in the most severely affected patients. The effectiveness and suitability of aggressive medical treatment with clean intermittent catheterization (CIC) is often questioned by the patient, their family, as well as other healthcare providers. N-of-1 studies are prospective, multiple crossover comparisons of alternative treatment options in a single patient. The main emphasis of the N-of-1 study design is to improve the care being delivered to an individual patient. The objective of this N-of-1 trial was to determine if patients with PUV could be allowed to void and be toilet trained or if they needed to continue with CIC to optimize their renal health.
A prospective IRB-approved N-of-1 study was performed to determine the efficacy of CIC and anti-cholinergic medication in the management of boys with PUV. After discussing the treatment options and selecting a clinical care plan, we collected baseline and post-intervention data. The response to intervention was measured by serum creatinine, cystatin C GFR and renal imaging. The results were shared with the parents and the next phase of the study was decided based on the clinical response. After a series of interventions were studied, the patients were maintained on the intervention that provided them with the best response to therapy. Parents were interviewed after the study to discern their satisfaction with the trial and its processes.
The graph represents the response of two of our patients to withdrawal of CIC with elevation of their GFR indicating hyperfiltration, considered to be an early marker of reversible renal injury. With re-institution of CIC and oxybutynin, the GFR returned to baseline levels. Parents that participated in the N-of-1 trials reported increased knowledge, awareness, and understanding of PUV and its renal implications. This was attributed to involving the families in data collection and also enabling them to actively participate in therapeutic decision-making during the trial.
N-of-1 trials aid in the shared decision making and enhance patient-centered care, by offering objective evidence of individual benefit and harm. These trials increase the involvement of the patient and their family thereby enhancing compliance in patients with chronic conditions such as PUV. We believe that N-of-1 trials are a way of avoiding the arbitrary physician-based decisions prevalent in clinical practice and aid in the development of personalized care plans and objectively help establish the most effective clinical pathway for a given patient. Widespread utilization of this research tool would greatly aid in achieving evidence-based everyday clinical practice, ultimately benefiting all of our patients.