Prevalence of vertebral fractures among patients with chronic obstructive pulmonary disease in Canada

Patients with chronic obstructive pulmonary disease (COPD) may be at higher risk for osteoporosis. The primary objective of this case-control study was to determine the prevalence of vertebral fractures among patients with COPD admitted to acute care compared with a gender- and age-matched control group.

Subjects were identified by chart reviews from an acute care hospital in Hamilton, Ontario, in 1999, including patients who were over 50 years old. In total, 127 patients with ICD-9 codes specifying COPD were randomly selected and compared with 127 gender- and age-matched controls. Chest radiographs were interpreted by two radiologists who defined and graded vertebral fractures using Genant's method. Medications taken, or prescribed at discharge, were recorded from charts.

The overall prevalence of at least one vertebral fracture was found to be 34/127 (26.8%) in the COPD patients compared with 30/127 (23.6%) in the controls ( p=0.556). A significantly greater proportion of COPD patients had at least one severe vertebral fracture (OR=3.75, 95% CI 1.24 to 11.3). Review of hospital chest X-ray reports indicated that only 12 of 64 (18.8%) patients with vertebral fractures identified by the study radiologists actually had a vertebral fracture noted in the report. The proportion of COPD patients with vertebral fractures who were discharged on osteoporosis therapy was 5/27 (18.5%). There was a suggestion of lower lung function, as measured by forced vital capacity (FVC%), in patients with severe vertebral fractures ( p=0.067).

These data indicate that: (1) There is an increased proportion of COPD patients with severe vertebral fracture, and (2) Documentation and treatment of osteoporosis in acute care COPD patients is low. Therefore, there is a need to target this high-risk group for osteoporosis screening and potential clinical management.