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Confirming the Diagnosis of COPD by Spirometry : A Clinical Review. Cary Peterson, DO FP PGYIII Supervising Physician: Keith Felstead, DO June 11, 2009. Introduction.
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Confirming the Diagnosis of COPD by Spirometry: A Clinical Review Cary Peterson, DO FP PGYIII Supervising Physician: Keith Felstead, DO June 11, 2009
Introduction Chronic Obstructive Pulmonary Disease (COPD) is a preventable and treatable disease. The disease is characterized by airfow limitation that is not fully reversible. The airflow limitation is usually progressive in nature (7).
Background • COPD was the 4th leading cause of death in 2002 and represents a significant economic burden, with an estimated $18 billion in direct and $14.1 billion in indirect costs annually (1). • According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD), “A diagnosis of COPD should be considered in any patient who has dyspnea, chronic cough or sputum production, and/or history of exposure to risk factors for the disease”. The diagnosis should by confirmed by: “SPIROMETRY” • Underuse may lead to an inaccurate COPD diagnosis
Diagnosis of COPD EXPOSURE TO RISK FACTORS SYMPTOMS cough tobacco sputum occupation shortness of breath indoor/outdoor pollution è è è SPIROMETRY
Changes in Lung Parenchyma in COPD Alveolar wall destruction Loss of elasticity Destruction of pulmonary capillary bed ↑ Inflammatory cells macrophages, CD8+ lymphocytes Source: Peter J. Barnes, MD
Why Perform Spirometry? - Measure airflow obstruction to help make a definitive diagnosis of COPD - Confirm presence of airway obstruction - Assess severity of airflow obstruction in COPD - Detect airflow obstruction in smokers who may have few or no symptoms - Monitor disease progression in COPD - Assess response to therapy (FEV1) in COPD - Perform pre-operative assessment
Types of Spirometers - Bellows spirometers: Measure volume; mainly in lung function units - Electronic desk top spirometers: Measure flow and volume with real time display - Small hand-held spirometers: Inexpensive and quick to use but have no print out
Standard SpirometricIndicies - FEV1 - Forced expiratory volume in one second: The volume of air expired in the first second of the forced expiration - FVC- Forced vital capacity: The total volume of air that can be forcibly exhaled in one breath - FEV1/FVC ratio: The fraction of air exhaled in the first second relative to the total volume exhaled
Spirometric Diagnosis of COPD - Confirmed by post–bronchodilator FEV1/FVC < 0.7 - Post-bronchodilator FEV1/FVC measured 15 minutes after 400µg salbutamol or equivalent - Helps to differentiate COPD from asthma • Must be interpreted with clinical history • Neither asthma nor COPD are diagnosed on spirometry alone
Reference Study 1 • “Spirometry Use in Clinical Practice Following Diagnosis of COPD” (4) • Published in Chest 2006 • Todd A. Lee, Brian Bartel and Kevin B. Weiss • Methods: • Cohort of pts > 40 years of age associated with Veterans Affairs Hospital • Diagnosed with COPD • Spirometry was identified over a 12 month period • Of 197,878 Pts only 33.7 % underwent spirometry • The use of spirometry for newly diagnosed COPD pts decreased with age and was 3.3 times higher for those visiting a pulmonologist • Conclusion: • Spirometry is inconsistently used in the diagnosis of COPD
Reference Study 2 • “Spirometry Utilization for COPD”(5) • Published in Chest 2007 • Meilan K. Han • Methods: • Subject data was collected on patients > 40 years of age from 5 different health plans recruited by “The National Committee for Quality Assurance” • New Diagnosis of COPD • Was spirometry done during the interval 720 days prior to diagnosis and ending 180 days after the dx. • Of the 5,039 pts studied, approximately 32% of the new diagnosis of COPD had undergone spirometry in the specified time frame. • Spirometry frequency was lowest in older patients, with the lowest frequency in those > 75 yoa. • Conclusion: • Study showed that spirometry is infrequently used in clinical practice for diagnosis of COPD and suggests opportunities for practice improvement.
Other Reasons for Spirometry Performance Measures: As of May 2009, Catholic IPA of Western NY collected data on 1,662 Medicare members with COPD and of those pts, 889 (53%) had spirometry (6).
Guidelines for Spirometry • In 2007, the American College of Physicians strongly recommended that pts with respiratory symptoms, particularly dyspnea, spirometry should by used to diagnose airflow obstruction (2). • However, the evidence did not support periodic spirometry after the initiation of therapy to monitor ongoing disease or to modify therapy (2). • But according to the GOLD, spirometry can be used to monitor disease progression, but to be reliable the intervals between measurements must be at least 12 months (6). • The US Preventive Services Task Force (USPSTF) recommends against screening adults for chronic obstructive pulmonary disease using spirometry (Grade D)(8).
Purpose of the Review The purpose of this review is to determine whether or not spirometry is adequately used to confirm the diagnosis of COPD in a small outpatient primary care setting.
Materials and Methods Chart Review (EMR From May 2007 – March 2009) Involved 1 Primary Care Outpatient Clinic Participants: Ages 43-89 yoa 55 patients were included Males-26 (47%) Females-29 (53%) Inclusion Criteria: 1. All patients had to have Electronic Medical Records (EMR) EMR defined as having PMHX tab completed 2. All patients had to have an EMR diagnosis of COPD – 496 Spirometry or pulmonary function testing (includes spirometric indices) @ anytime as documented in the EMR Chart was included as long as the inclusion criteria was met.
Results • Primary end points: • 14 patients (25%) had spirometry documented • 17 patients (31%) had pulmonary function testing documented • Total of 31 (56%) of the 55 patients had either PFT’s or spirometry documented in EMR with a corresponding diagnosis of COPD
Results • Secondary Endpoints: • 45 of 55 patients (82%) were on COPD medications • 30 patients (55%) in this study had a diagnosis of Smoking use (305.1)
Comments • It should be noted that there was a much smaller studied population than with the 2 larger studies. • Also, in this study, the inclusion population only included those who were completely EMR. • There are large numbers who are still in paper charts that were not accounted for which could have also affected the results. • Incomplete EMR conversion and a lack of spirometry/PFT entry also could have affected the study. • The time line in our study was broader, with a 2 year window for spirometry to confirm the COPD diagnosis.
Conclusion • As shown in the references articles, spirometry use in outpatient primary care offices has been less than adequate to either establish or support the diagnosis of COPD. • In this review, the clinic did have a higher percentage of documented spirometry or pulmonary function testing then the 2 reference studies as well as the CIPA study group. • Men and women were tested equally. • There is also abundant information that smoking is a major contributor to COPD and was once again confirmed in this study as noted in the secondary endpoints. • It does appear that COPD and it’s diagnosis, however it is made was documented to be treated aggressively in our studied outpatient setting with almost 82% of subjects on some form of COPD treatment. • Smoking must continually be addressed in whatever medical setting one is involved. • There must be added emphasis in assuring that COPD is confirmed in our primary care community through the use of spirometry and/or PFT’s. • Physicians in the future can be assured that they are employing gold standard care to their patients when they use spirometry in their offices.
References • Chronic obstructive pulmonary disease: national clinical guideline on management of chronic obstructive pulmonary disease in adults in primary and secondary care. National Collaborating Centre for Chronic Conditions. Thorax 2003, 59 (suppl 1); 1-232. • Diagnosis and Management of Stable Chronic Obstructive Pulmonary Disease: A Clinical Practice Guideline from the American College of Physicians. Annals of Internal Medicine 2007; 633-638. • Global Initiative for Chronic Obstructive Lung Disease. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease (updated 2008). • Lee TA, Bartle B, Weiss KB. Spirometry use in clinical practice following diagnosis of COPD. Chest 2006; 129 (6): 1509-15.
References • Han MK, Kim MG, Mardon R, et al. Spirometry utilization for COPD: How do we measure up? Chest 2007; 132: 403-09. • Medicare Data on Spirometry and COPD from Catholic Independent Practice Association, Dr. Mike Edbauer (Medical Director), May 27, 2009. • Pocket Guide to COPD Diagnosis, Management, and Prevention; A Guide for Health Care Professionals. Global Initiative for Chronic Obstructive Lung Disease (Updated 2008). 8. Screening for Chronic Obstructive Pulmonary Disease Using Spirometry: U.S. Preventative Services Task Force Recommendation Statement. Annals of Internal Medicine 2008; 148: 529-534.