BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a chronic respiratory condition characterised by shortness of breath, cough and recurrent exacerbations. People with COPD often live with one or more co-existing long-term health conditions (comorbidities). People with more severe COPD often have a higher number of comorbidities, putting them at greater risk of morbidity and mortality.
OBJECTIVES: To assess the effectiveness of any single intervention for COPD adapted or tailored to their comorbidity(s) compared to any other intervention for people with COPD and one or more common comorbidities (quantitative data, RCTs) in terms of the following outcomes: Quality of life, exacerbations, functional status, all-cause and respiratory-related hospital admissions, mortality, pain, and depression and anxiety. To assess the effectiveness of an adapted or tailored single COPD intervention (simple or complex) that is aimed at changing the management of people with COPD and one or more common comorbidities (quantitative data, RCTs) compared to usual care in terms of the following outcomes: Quality of life, exacerbations, functional status, all-cause and respiratory-related hospital admissions, mortality, pain, and depression and anxiety. To identify emerging themes that describe the views and experiences of patients, carers and healthcare professionals when receiving or providing care to manage multimorbidities (qualitative data).
SEARCH METHODS: We searched multiple databases including the Cochrane Airways Trials Register, CENTRAL, MEDLINE, Embase, and CINAHL, to identify relevant randomised and qualitative studies. We also searched trial registries and conducted citation searches. The latest search was conducted in January 2021.
SELECTION CRITERIA: Eligible randomised controlled trials (RCTs) compared a) any single intervention for COPD adapted or tailored to their comorbidity(s) compared to any other intervention, or b) any adapted or tailored single COPD intervention (simple or complex) that is aimed at changing the management of people with COPD and one or more comorbidities, compared to usual care. We included qualitative studies or mixed-methods studies to identify themes.
DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods for analysis of the RCTs. We used Cochrane's risk of bias tool for the RCTs and the CASP checklist for the qualitative studies. We planned to use the Mixed Methods Appraisal tool (MMAT) to assess the risk of bias in mixed-methods studies, but we found none. We used GRADE and CERQual to assess the quality of the quantitative and qualitative evidence respectively. The primary outcome measures for this review were quality of life and exacerbations.
MAIN RESULTS: Quantitative studies We included seven studies (1197 participants) in the quantitative analyses, with interventions including telemonitoring, pulmonary rehabilitation, treatment optimisation, water-based exercise training and case management. Interventions were either compared with usual care or with an active comparator (such as land-based exercise training). Duration of trials ranged from 4 to 52 weeks. Mean age of participants ranged from 64 to 72 years and COPD severity ranged from mild to very severe. Trials included either people with COPD and a specific comorbidity (including cardiovascular disease, metabolic syndrome, lung cancer, head or neck cancer, and musculoskeletal conditions), or with one or more comorbidities of any type. Overall, we judged the evidence presented to be of moderate to very low certainty (GRADE), mainly due to the methodological quality of included trials and imprecision of effect estimates. Intervention versus usual care Quality of life as measured by the St George's Respiratory Questionnaire (SGRQ) total score may improve with tailored pulmonary rehabilitation compared to usual care at 52 weeks (mean difference (MD) -10.85, 95% confidence interval (CI) -12.66 to -9.04; 1 study, 70 participants; low-certainty evidence). Tailored pulmonary rehabilitation is likely to improve COPD assessment test (CAT) scores compared with usual care at 52 weeks (MD -8.02, 95% CI -9.44 to -6.60; 1 study, 70 participants, moderate-certainty evidence) and with a multicomponent telehealth intervention at 52 weeks (MD -6.90, 95% CI -9.56 to -4.24; moderate-certainty evidence). Evidence is uncertain about effects of pharmacotherapy optimisation or telemonitoring interventions on CAT improvement compared with usual care. There may be little to no difference in the number of people experiencing exacerbations, or mean exacerbations with case management compared with usual care (OR 1.09, 95% CI 0.75 to 1.57; 1 study, 470 participants; very low-certainty evidence). For secondary outcomes, six-minute walk distance (6MWD) may improve with pulmonary rehabilitation, water-based exercise or multicomponent interventions at 38 to 52 weeks (low-certainty evidence). A multicomponent intervention may result in fewer people being admitted to hospital at 17 weeks, although there may be little to no difference in a telemonitoring intervention. There may be little to no difference between intervention and usual care for mortality. Intervention versus active comparator We included one study comparing water-based and land-based exercise (30 participants). We found no evidence for quality of life or exacerbations. There may be little to no difference between water- and land-based exercise for 6MWD (MD 5 metres, 95% CI -22 to 32; 38 participants; very low-certainty evidence). Qualitative studies One nested qualitative study (21 participants) explored perceptions and experiences of people with COPD and long-term conditions, and of researchers and health professionals who were involved in an RCT of telemonitoring equipment. Several themes were identified, including health status, beliefs and concerns, reliability of equipment, self-efficacy, perceived ease of use, factors affecting usefulness and perceived usefulness, attitudes and intention, self-management and changes in healthcare use. We judged the qualitative evidence presented as of very low certainty overall.
AUTHORS' CONCLUSIONS: Owing to a paucity of eligible trials, as well as diversity in the intervention type, comorbidities and the outcome measures reported, we were unable to provide a robust synthesis of data. Pulmonary rehabilitation or multicomponent interventions may improve quality of life and functional status (6MWD), but the evidence is too limited to draw a robust conclusion. The key take-home message from this review is the lack of data from RCTs on treatments for people living with COPD and comorbidities. Given the variation in number and type of comorbidity(s) an individual may have, and severity of COPD, larger studies reporting individual patient data are required to determine these effects.
