‘Idiopathic pulmonary fibrosis’ (IPF), one of the prime variants of ‘idiopathic interstitial pneumonia’, is a recurrent, progressive, irreversible and generally lethal lung disease of unknown origin 1. Men and women are frequently affected, with poor median survival; and the survival varies between two and five years 1,2. The incidence of IPF varies across the globe and ranges between 0.2 and 93.7 per 100,000 population per year 2. There is diversity in age standardised mortality rate of IPF between different countries (4.64 to 8.28 per 100,000 population); however, data were mostly available from few high-income countries 2. Increasing trend in IPF has been reported over the years in many countries 2. Cigarette smoking and exposure to metal and wood emissions were the most important environmental threats for developing IPF 1,4,5.
IPF individuals seek treatment for chronic and progressive cough and dyspnoea. Dyspnoea and fatigue deteriorate functional ability and quality of life in individuals with IPF. As fibrosis progresses, dyspnoea and fatigue intensify, individual with IPF become gradually less physically involved and unable to perform physical tasks 3,6,7.
Pharmacotherapy (pirfenidone and nintedanib) is a promising approach in the management of mild to moderately impaired lung function tests among IPF 8. Additionally, IPF involves the application of home-based pulmonary rehabilitation (PR) program to optimise functional outcomes 9,10. Individually tailored exercise training is the cornerstone of PR. The exercise training component included both aerobic and strength training 9,11 and each session may consist of up to 30 minutes of aerobic training 12. PR, a systematic technique, improves dyspnoea, enhances exercise efficiency, and improves health-related quality of life (HRQoL) 13. PR is commonly delivered in an outpatient or community setting and may comprise of two - three sessions per week 14. Disease-specific education and self-management training helps people with IPF to develop and implement the skills necessary to perform the tasks, guide behaviour change and provide support to achieve optimal function 14,15.
Despite the proven benefits of PR for individuals with ‘chronic respiratory diseases’ (CRD), a small percentage of individuals who are eligible to attend PR adhere to it on regular basis 16. Some of the patient-centred barriers to attendance and adherence of PR are related to travel and transport to the rehabilitation centre. Lack of services and suitably trained healthcare professionals, especially in non- metropolitan areas make it difficult to avail the services 16,17. Home-based PR has the potential to overcome known barriers to PR participation and could be a relevant treatment alternative across all CRD including IPF 14.
The empirical research has shown the benefits of PR in enhancing functional capability and HRQoL, thereby minimising hospitalisation and frequency of hospital stay 18. PR programs are demonstrated to be successful by home-based mode of rehabilitation for training, and therefore, previous research had recommended creation of such programmes 19,20,21. Home-based PR programmes, for a larger proportion of IPF individuals living in lesser developed countries or rural and remote surroundings, may contribute to broader provision of PR. Furthermore, unsupervised home-based PR can be a promising approach for a resource-limited remote area of the world.
Previous systematic reviews for supervised exercise training programs have exhibited clinical benefits in ameliorating exercise capacity, dyspnoea and quality of life in individuals with IPF 9,12,22. A systematic review 9 included studies conducted a mixture of centre- and home-based setting to assess the effects of exercise-based PR in individuals with IPF. As the subgroup analysis was not conducted it is difficult to comment on which of the two settings proved to be beneficial. The underlying effects of chronic adaptation to a regular non-supervised home-based PR on functional capacity in IPF has yet to be described by a systematic review level evidence. There has not been a comprehensive assessment of the capacity of non-supervised home-based PR to achieve improvements in functional capacity using 6-minute walk test 23, shuttle walk test 24, incremental shuttle walk test and HRQoL 18,25,26 in people with IPF, or its ability to improve uptake and access to rehabilitation services.
The current systematic review is, therefore, planned to evaluate the effectiveness of an unsupervised selfcare home-based PR training program on the functional capacity in individuals with IPF. The evidence generated from this systematic review will guide policy makers, researchers and public health practitioners in designing evidence-based PR program performed at home, which might help in improving the HRQoL, activity of daily living and bring about functional improvements among people with IPF. It would provide basis for establishing a standard protocol and an alternative to supervised centre-based rehabilitation programs for individuals with IPF.