In patients with pulmonary hypertension (PH) undergoing rehabilitation, greater inclusion of outcome measures that reflect activity and participation in society, rather than body functions/structure, is needed to facilitate accurate assessment of the wider effect of this intervention. A systematic review of the literature was performed to identify studies of rehabilitation conducted in patients with PH between 2006 and 2019. Results of the analysis were published in the Annals of the American Thoracic Society.
Recognizing that the World Health Organization International Classification for Functioning, Disability and Health identifies 3 different health domains — body functions/structures, activity, and participation in society — investigators sought to ensure that the study end points used to evaluate patients with PH undergoing rehabilitation were reflective of all 3 of these measures. Searches were performed across 5 databases and yielded a total of 2564 articles, with 34 meeting eligibility criteria.
A total of 50 different outcome measures were identified. The studies used an average of 5 outcome measures (minimum=1; maximum=9), providing a total of 176 instances of outcome measure usage across the studies. The most often used measures were exercise testing (n=56), quality of life (QoL) measures (n=31), and biomarkers (n=23), with a few different outcomes appearing within each category. In 32 of the 34 studies, the 6-minute walking distance (6MWD) was used as a gauge. Of the remaining 2 studies, 1 used cardiopulmonary exercise testing and 1 used attainable treadmill speed. In 26% (9 of 34) of the studies, no QoL measure was used. In fact, 2 of these studies used symptom-specific patient-reported outcomes.
A majority of the publications evaluated (94%) had been conducted in the last 10 years, which reflects an increased number of randomized controlled studies during that time. The studies were most often carried out in patients with pulmonary arterial hypertension (56%) or in those with PH of a nonspecified cause (29%). Although the rehabilitation interventions used differed in their content and length, they were most often a type of whole-body exercise training that involved a combination of cardiovascular, respiratory, and resistance training, along with education about the disease and management of its symptoms.
Of the 34 studies included in the review, 48% of the instances of outcome usage were measures of body function/structure, 33% were measures of activity, and 18% were measures of participation. In fact, 7 of the 34 studies did not include any measures of participation.
The investigators concluded that future studies of rehabilitation in individuals with PH need to evaluate change across a broad spectrum of patients’ lives. Once ideal measures are used to capture rehabilitation outcomes, this will allow the design, commissioning, and delivery of services that best meet the needs of individual patients with PH.
Keen C, Harrop D, Hashmi-Greenwood MN, Kiely DG, Yorke J, Sage K. Outcome measures used in studies of rehabilitation in pulmonary hypertension: a systematic review. Ann Am Thorac Soc. Published online September 18, 2020. doi: 10.1513/AnnalsATS.202005-541OC