Muscle Loss Phenotype in COPD May Increase Mortality, Costs

In patients with chronic obstructive pulmonary disease (COPD) who are hospitalized for an exacerbation, mortality, length of stay (LOS), and cost all have been shown to be considerably higher in those with a muscle loss phenotype, according to study results published in Respirology.

Recognizing that the effect of muscle loss on adverse outcomes in patients with COPD has not been systematically assessed, the investigators sought to explore whether patients who were admitted to the hospital for a COPD exacerbation with a secondary diagnosis of muscle loss phenotype would have higher rates of mortality and healthcare costs compared with those without a muscle loss phenotype. Therefore, they conducted an analysis of national trends via use of the US Nationwide Inpatient Sample database was conducted between January 1, 2011, and December 31, 2011.

The primary study outcome was in-hospital mortality in patients with COPD exacerbations with or without a muscle loss phenotype. Additional outcomes included LOS and cost of care.

All of the study participants were aged ≥35 years. The mean age of the hospitalized patients was 67.5±14.5 years. During the study year of 2011, a total of 174,808 hospitalizations for a COPD exacerbation were reported. Overall, 6.3% (11,066 of 174,808) of the hospitalizations for a COPD exacerbation was associated with in-hospital mortality.

The prevalence of a muscle loss phenotype was significantly higher in patients with a COPD exacerbation compared with a random sample of general medical hospital inpatients (7.4% vs 4.1%, respectively; P <.001). Following adjustment for sex, age, and comorbidities, the odds ratio for a muscle loss phenotype in patients with COPD compared with general medical inpatients was 1.39 (95% CI, 1.32-1.45).

Of those patients who were hospitalized for an exacerbation of COPD, 7.4% (12,977 of 174,808) of them were determined to have a muscle loss phenotype. Those individuals with a COPD exacerbation and a muscle loss phenotype were significantly older compared with those without any muscle loss (P <.001). Further, those patients with COPD who were hospitalized with a muscle loss phenotype vs those without a muscle loss phenotype were significantly more likely to require transfer to a skilled nursing facility (45.3% vs 18.9%, respectively; P <.001) or to require home health care (21.8% vs 16.8%, respectively; P <.001) than to be transferred home to live independently (27.7% vs 60.4%, respectively).

The presence of a muscle loss phenotype vs the absence of a muscle loss phenotype was associated with significantly higher in-hospital mortality (14.6% vs 5.7%, respectively; P <.001), longer LOS (13.3±17.1 days vs 5.7±7.6 days, respectively; P <.001), and higher median hospital charge per patient ($13,947 vs $6610, respectively; P <.001). Per multivariate regression analysis, the presence of a muscle loss phenotype significantly increased mortality by 111% (95% CI, 2.0-2.2; P <.001), LOS by 68.4% (P <.001), and the direct cost of care by 83.7% (P <.001), compared with the absence of any muscle loss.

The investigators concluded that the findings from this study support the development of strategies and the allocation of resources at the national level, which are intended to improve clinical outcomes and decrease healthcare resource utilization and costs in patients with COPD.

Reference

Attaway AH, Welch N, Hatipoğlu U, Zein JG, Dasarathy S. Muscle loss contributes to higher morbidity and mortality in COPD: an analysis of national trends [published online June 16, 2020]. Respirology. doi:10.1111/resp.13877