Introduction
Asthma is one of the most common chronic diseases worldwide with an estimated 300 million affected individuals [
1]. Asthma was defined by the Global Initiative for Asthma (GINA) as a heterogeneous disease, usually characterized by chronic airway inflammation and a history of respiratory symptoms that vary over time and in intensity, including wheeze, shortness of breath, chest tightness and cough, together with variable expiratory airflow limitation [
1]. Thus, the diagnosis of asthma is primarily based on clinical symptoms [
2]. In spite of the availability of effective medications, it remains incurable. Various cross-sectional studies have shown a high number of patients with poorly controlled asthma in many countries [
3,
4]. Therefore, new approaches to improve asthma control (AC) are urgently required.
Pulmonary rehabilitation (PR) is widely accepted as an effective treatment for patients with chronic respiratory diseases, especially for chronic obstructive pulmonary disease (COPD) [
5]. In Europe and North America, asthma patients are also commonly enrolled in PR programs [
6], but the available data regarding the effectiveness of PR for asthma patients are sparse. Only very few randomized studies [
7,
8] concerning the effectiveness of a multimodal PR program in asthma have been published. All had certain methodological limitations, so that they weren’t considered for international evidence-based asthma guidelines [
1,
2].
However, the effectiveness of the essential individual components of PR, such as patient education [
9,
10], respiratory physiotherapy [
11,
12] and aerobic exercise training [
13‐
18] has been shown in several randomized controlled trails (RCTs). As a complete PR program is expected to be at least as effective as these single components, the German National Disease Management Guideline [
19] recommends PR for asthma patients if physical, mental or social consequences of the illness are constraining and persist during daily life despite adequate medical therapy.
Besides the two RCTs [
7,
8], a limited number of observational studies have been published in the international [
20‐
24] and German literature [
25‐
27]. They have shown positive effects regarding quality of life, clinical symptoms, physical function, exacerbations, and health care resource utilisation. However, up to now, no RCTs have addressed the question whether and how long asthma control improves after PR. Therefore, such a study was strongly recommended by the German National Disease Management Guideline [
19].
This lack of evidence is of particular relevance since asthma is a common indication for PR in Europe and in the US [
6], and is the most frequent indication for PR in Germany [
28]. Therefore, the main objective of the EPRA-RCT is to fill the knowledge gap for PR in asthma. Moreover, there is little empirical data regarding the long-term course of AC, quality of life and self-management skills after PR for asthma and the cost-effectiveness. As part of the EPRA study a follow-up assessments at 6, 9 and 12 months after PR will be provided.
Study aims
The primary aim of this RCT is to evaluate the effectiveness of PR for patients with asthma on short (end of rehabilitation) and intermediate-term (3 months after rehabilitation) outcomes as compared to a waiting-list control group. We hypothesize that pulmonary inpatient rehabilitation is superior regarding mean change in AC at 3 months after rehabilitation (primary outcome). Furthermore, we expect superior effectiveness of the pulmonary rehabilitation regarding health related quality of life (HRQoL), functional exercise capacity, dyspnea, anxiety, depression, subjective self-management skills, illness perceptions, sick leave, as well as subjective work ability (secondary outcomes). In addition, moderator effects of (a) gender, (b) age, (c) baseline AC, (d) baseline HRQoL and (e) baseline anxiety will be examined. Moreover, in a longitudinal follow-up study, the course of primary and secondary outcomes over one year and the annual costs before and after rehabilitation will be explored.