The Gini Coefficient: A New Approach to Assess Physical Activity Inequality in COPD

Abstract

Increasing physical activity (PA) is a complex and challenging task in patients with chronic obstructive pulmonary disease (COPD). However, some questions are raised regarding the evaluation of PA in these patients: Have all aspects of PA evaluation in patients with COPD already been explored in the scientific literature and clinical practice? What is the clinical importance of assessing PA inequality? PA inequality is defined as the Gini coefficient (Gini_coef) of the PA distribution of a population and is already shown to have implications for public health in the general population. It is a simple tool that might allow a better understanding of PA disparities among different COPD populations, although to our knowledge there is no previous investigation of PA inequality in patients with COPD using the Gini_coef. In this perspective study we have provided examples of the Gini_coef use in different scenarios. Future studies might try to apply it in order to identify subpopulations with higher PA inequality, and perhaps are therefore more prone to benefit most from interventions specifically tailored to promote PA. In summary, we propose the quantification of PA inequality with the Gini_coef as a tool that might allow us to see PA even more comprehensively than we already do, expanding our perspective on PA in patients with COPD.

Keywords:

• Chronic obstructive pulmonary disease
• activity
• statistical methods
• steps/day

Acknowledgements

RPH, JMO, LPS, MPB, AR, LCM, FP and KCF were supported by individual grants from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) or Fundação Nacional do Desenvolvimento do Ensino Superior Particular (FUNADESP).

Disclosure statement

The authors report no conflict of interest.

Supplemental online material

A spreadsheet file is available for download with further explanations about how the Gini coefficient can be calculated as well as an example with real data.

Additional information

Funding

RPH is supported by a scholarship from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), grant number 151647/2019-4; FP is supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), grant number 303131/2017-9; and KCF is supported by Fundação Nacional do Desenvolvimento do Ensino Superior Particular (FUNADESP), grant number 5301164.