Balance Impairment in individuals with COPD: A Systematic Review with Meta-Analysis

Background: People with Chronic Obstructive Pulmonary Disease (COPD) are four times more likely to fall than healthy peers, leading to increased morbidity and mortality. Poor balance is a major risk factor for falls. This review aims to quantify the extent of balance impairment in COPD, and establish contributing clinical factors, which at present are sparse. Methods: Five electronic databases were searched, in July 2017 and updated searches were performed in March 2019, for studies comparing balance in COPD with healthy controls. Metaanalyses were conducted on sample mean differences (MD) and reported correlations between balance and clinical factors. Meta-regression was used to quantify the association between mean difference in % predicted forced expiratory volume in 1 second (FEV1) and mean balance impairment. Narrative summaries were provided where data were insufficient for meta-analysis. Results: Twenty-three studies were included (n=2,751). Meta-analysis indicated COPD patients performed worse than healthy controls on Timed Up and Go (MD=2.77 s, 95%CI: 1.46s to 4.089, p=<0.005), Single Leg Stance (MD=-11.75s, 95% CI: -15.12s to -8.38s, p=<0.005) and Berg Balance Scale (MD= -6.66, 95% CI -8.95 to -4.37, p=<0.005). The pooled correlation coefficient between balance and reduced quadriceps strength was weak-moderate (r=0.37, 95%CI: 0.23 to 0.45, p<0.005). The relationship between differences in % predicted FEV1 and balance were negligible (r2 = < 0.04). Conclusions: Compared healthy controls, people with COPD have a clinically meaningful balance reduction, which may be related to reduced muscle strength, physical activity and exercise capacity. Our findings support a need to expand the focus of pulmonary rehabilitation to include balance assessment and training, and further exploration of balance impairment in COPD.