Hospital admissions and mortality in patients with COPD exacerbations and vertebral body compression fractures

Abstract

Background: Vertebral compression fractures (VCF) are common in COPD patients, with osteoporosis being the main cause. The clinical impact of VCF derives mostly from both pain and chest deformity, which may lead to ventilatory and physical activity limitations. Surprisingly, the consequences of VCF on the quality outcomes of hospital care are poorly known.

Objective: To assess these indicators in patients hospitalized due to a COPD exacerbation (ECOPD) who also have VCF.

Methods: Clinical characteristics and quality care indicators were assessed in two one-year periods, one retrospective (exploratory) and one prospective (validation), in all consecutive patients hospitalized for ECOPD. Diagnosis of VCF was based on the reduction of >20% height of the vertebral body evaluated in standard lateral chest X-ray (three independent observers).

Results: From the 248 patients admitted during the exploratory phase, a third had at least one VCF. Underdiagnosis rate was 97.6%, and patients with VCF had more admissions (normalized for survival), longer hospital stays, and higher mortality than patients without (4 [25th-75th percentiles, 2-8] vs 3 [1-6] admissions, P<0.01; 12 [6-30] vs 9 [6-18] days, P<0.05; and 50 vs 32.1% deaths, P<0.01, respectively). The risk of dying in the two following years was also higher in VCF patients (odds ratio: 2.11 [1.2-3.6], P<0.01). The validation cohort consisted of 250 patients who showed very similar results. The logistic regression analysis indicated that both VCF and age were factors independently associated with mortality.

Conclusion: Although VCF is frequently underdiagnosed in patients hospitalized for ECOPD, it is strongly associated with a worse prognosis and quality care outcomes.

Keywords: COPD; hospitalizations; prognosis; vertebral fracture.

Figure 1

Lateral projection of a chest radiograph. Notes: Wedge fractures can be observed in different vertebral bodies. That of T9 is severe (loss of >40% of its anterior component) and that of L1 can be considered as moderate (25%–40% loss) according to Genant’s classification. No vertebra presents retropulsion of the posterior wall or associated listhesis.

Figure 2

Comparison between patients with and without at least one VCF. Notes: (A) Hospital admissions and (B) Mean length of hospital stays. *P<0.05; **P<0.01. Abbreviation: VCF, vertebral compression fractures.

Figure 3

Mortality in the two cohorts during the two years follow-up of the ECOPD that led to the inclusion in the study. Notes: Continuous bold line, patients with VCF; dashed line, patients without VCF. Abbreviations: VCF, Vertebral compression fractures; ECOPD, COPD exacerbation.