Spirometry use among older adults with chronic obstructive pulmonary disease: 1999-2008

Abstract

Rationale: Clinical practice guidelines recommend spirometry to diagnose chronic obstructive pulmonary disease (COPD) and facilitate management. National trends in spirometry use in older adults with newly diagnosed COPD are not known.

Objectives: To examine the rate and beneficiary characteristics associated with spirometry use in subjects with newly diagnosed COPD between 1999 and 2008.

Methods: We examined newly diagnosed beneficiaries with COPD using a 5% Medicare population from 1999 to 2008. A new COPD diagnosis required two outpatient visits or one hospitalization with primary International Classification of Diseases, 9th edition code 491.xx, 492.xx, or 496 occurring at least 30 days apart with none in the prior 12 months. The primary measurement was spirometry performed within 365 days (±) of the first claim with a COPD diagnosis.

Measurements and main results: Between 1999 and 2008, 64,985 subjects were newly diagnosed with COPD. Of these, 35,739 (55%) had spirometry performed within 1 year before or after the initial diagnosis of COPD. Spirometry use increased from 51.3% in 1999 to 58.3% in 2008 (P < 0.001). Subjects with younger age, men, whites, those with higher socioeconomic status, and those with a greater number of comorbidities were more likely to have spirometry. In a multivariable analysis, compared with 1999, subjects diagnosed in 2008 had 10% higher odds (odds ratio, 1.10; 95% confidence interval, 1.06-1.13) of having spirometry performed.

Conclusions: Despite an increase in the use of spirometry over time in newly diagnosed older adults with COPD, spirometry use remains low. Clinical practice guidelines and educational efforts should focus on increasing the use of spirometry to diagnose and manage COPD.

Figure 1.

Percent of patients with spirometry within one year (±365 d) of diagnosis of chronic obstructive pulmonary disease (COPD) by (A) age, (B) sex, (C) race, and (D) number of comorbidities and year of diagnosis of COPD. All P values of trend test were < 0.0001.

Figure 2.

(A) Percent of patients newly diagnosed with chronic obstructive pulmonary disease (COPD) who had spirometry (±365 d) by U.S. states (1999–2001). (B) Percent of patients newly diagnosed with COPD who had spirometry (±365 d) by U.S. states (2006–2008). Insufficient data is defined as fewer than 100 patients in the region.