Objective:

To explore the feasibility of daily diaries as an outcome measure in Postural Orthostatic Tachycardia Syndrome (POTS) patients in a clinical trial context. 

Background:

POTS, the most common dysautonomia, predominantly affects young women and may occur with systemic autoimmune disease or recent infection. Symptom severity measured at a single time point may not accurately reflect clinical changes. There is currently no POTS-specific patient reported outcome measure. Patient diaries have been used to help track symptoms and compliance in other disorders, but their reliability and value in POTS has not been evaluated. 

Design/Methods:

This secondary study was conducted during a randomized controlled clinical trial evaluating intravenous immunoglobulin (IVIG) compared to albumin infusions in patients with POTS. In addition to regular visits, participants completed a standardized daily symptom/activity diary. The daily diary entry included daily water intake, exercise type and duration, and Likert rating of overall POTS symptoms from 0 (no symptoms) to 10 (most severe). Completed diaries were collected at each study visit. 

Results:

Daily diary completion was 96.8% during the first 15 weeks of the study (n = 27) and 97.8% for the entire 32 weeks (n = 21). Participants reported compliance with fluid intake recommendations (2 L per day) 75.8% of days during the first 15 study weeks, and 80.1% for the full 32 weeks. Overall, the diary study showed daily symptom severity correlated with primary outcome measures. 

Conclusions:

Use of a daily symptom diary for POTS patients is feasible. A symptom and activity diary may not only provide additional clinical data but may also improve compliance with recommendations for daily fluid intake and exercise. Daily POTS diaries could be used effectively in future intervention trials or as an adjunct to standard practice.