Systematic Review of the Methodological Quality and Outcome Measures Utilized in Exercise Interventions for Individuals with Cystic Fibrosis

Background: The aims of this study were to evaluate the methodological quality of interventional exercise studies in individuals with cystic fibrosis (CF) and link the reported outcome measures of these studies to the International Classification of Functioning, Disability and Health (ICF) model.

Methods: Electronic searches of PubMed, Scopus, Embase, CINAHL, SPORTDiscus, and Cochrane review were performed in the spring of, 2022. The methodological quality of studies was evaluated using the Effective Public Health Practice Project Quality Assessment Tool (EPHPP). Outcome measures were linked to the categories and sub-categories of the ICF model using ICF linking rules.

Results: We screened 4,769 studies and extracted data from 89 eligible manuscripts. Of these. 41% were one group, pre-post design; 36% were RCTs; 11% were two-group pre-post design; 6% were controlled clinical trials; and 6% were either case reports or case series. Using the (EPHPP), 49% were ranked as high quality, 34% moderate, and 17% low. In addition, body function was the most addressed ICF category followed by activities/participation and, subsequently, body structure.

Significance: This review supports the recommendation of exercise as an intervention to improve a variety of outcomes, ranging from Body structure (e.g., body composition) to Participation (e.g., engaging in community, social, and civic life). We recommend that investigators review the spectrum of potential ICF outcomes when designing rehabilitation trials, to both reflect the potential effects of exercise on a variety of outcomes, but also to facilitate mechanistic studies that are able to link which body structures and body functions are most important to improving patient outcomes at the activity and participation domains. Addressing environmental factors within the ICF is also important for people with CF, such as resource allocation towards exercise and rehabilitation resources. Finally, this review highlights the need for more vigorous methodological designs to minimize risk of bias and improve quality of exercise studies in CF.