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Procedural Variation May Contribute to 6-Minute Walk Distance Variability in Real-World Pediatric Pulmonary Arterial
Cynthia Kleppinger1, Dunbar Ivy2, Norman Stockbridge1
1US Food and Drug Administration Silver Spring, Maryland, United States of America.
Insights
Procedural variations in the six-minute walk test (6MWT) for pediatric pulmonary arterial hypertension (PAH) impact results. Standardizing the 6MWT in children is crucial for consistent exercise capacity assessments.
Area of Science:
- Pediatric Cardiology
- Pulmonary Hypertension Research
- Clinical Exercise Physiology
Background:
- The six-minute walk test (6MWT) is a key assessment for exercise capacity in pediatric pulmonary arterial hypertension (PAH).
- Current guidelines for the 6MWT are not specific to pediatric populations.
- Variations in test procedures may affect outcomes in children with PAH.
Purpose of the Study:
- To evaluate the impact of procedural variations on 6MWT outcomes in pediatric PAH.
- To identify potential sources of variability in the six-minute walk distance (6MWD) in a real-world clinical setting.
Main Methods:
- Observational pilot study involving 33 children with PAH across five centers.
- Collected 6MWT data, analyzing range, quantiles, and standard deviation for 6MWD variability.
- Compared data from sites with differing procedural elements (e.g., environment, parental involvement).
Main Results:
- Significant differences in mean 6MWD and variability were observed between sites with distinct procedural variations (Site D vs. Site E: 547m vs. 432m, p=0.03).
- Procedural variations, such as testing environment and caregiver involvement, appear to influence 6MWD results.
- Data showed considerable range and standard deviation in 6MWD across participating centers.
Conclusions:
- Procedural variations in the pediatric 6MWT are associated with variability in 6MWD results.
- Standardization of pediatric 6MWT protocols is necessary for reliable and comparable assessments.
- Further research with larger sample sizes is needed to confirm these findings.
Abstract:
The six-minute walk test (6MWT) is a common method to assess submaximal exercise capacity in children and adults with pulmonary arterial hypertension (PAH) and other chronic diseases. There is no guideline specifically for 6MWT in children. In this observational pilot study, we evaluated the impact of procedural variations on the outcome of the 6MWT in the real-world clinical setting at pediatric PAH programs. We collected 6MWT data from 33 children with PAH participating in a multicenter, prospective, non-interventional study. Data range/quantiles and standard deviation (SD) were used to describe distribution of the six-minute walk distance (6MWD) and data variability. Levene's test was used to test for heterogeneity of variance with the two sites of similar altitude and their age/height/weight-matched Panama Function Class II participants. We analyzed all 33 eligible participants and their qualified first walks at five centers (A-E) with 6MWD ranges of 420-570, 357-683, 418-481, 400-700, 377-549 m, respectively. Site D performed the 6MWT in a busy hallway and allowed parental/caregiver's cheering, while Site E performed the 6MWT in a secluded area with no parental/caregiver involvement. Mean 6MWD and SD for Sites D and E were 547 (125) and 432 (67.5) meters, respectively (p = 0.03). In conclusion, procedural variations seem to associate with 6MWD data variability. Although interpretation of our results is limited by the small sample size, our findings suggest that standardizing pediatric 6MWT procedures are needed.
