Association between Spirometric Parameters and Depressive Symptoms in New Mexico Uranium Workers

Shiva Sharma MD, MPH¹

Xin W. Shore MS²

Satyajit Mohite MD, MPH³

Orrin Myers PhD²

Denece Kesler MD, MPH¹

Kevin Vlahovich MD, MS¹

Akshay Sood MD, MPH⁴

¹Preventive Medicine Section, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM USA

²Department of Family and Community Medicine, University of New Mexico School of Medicine, Albuquerque, NM USA

³Department of Behavioral Health, Psychiatry & Psychology, Mayo Clinic Health System, Mankato, MN USA

⁴Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM USA

Abstract

Background: Uranium workers are at risk of developing lung disease, characterized by low forced expiratory volume in one second (FEV1) and/or forced vital capacity (FVC). Previous studies have found an association between decreased lung function and depressive symptoms in patients with pulmonary pathologies, but this association has not been well examined in occupational cohorts, especially uranium workers.

Methods: This cross-sectional study evaluated the association between spirometric measures and depressive symptoms in a sample of elderly former uranium workers screened by the New Mexico Radiation Exposure Screening & Education Program (NM-RESEP). Race- and ethnicity-specific reference equations were used to determine predicted spirometric indices (predictor variable). At least one depressive symptom [depressed mood and/or anhedonia, as determined by a modified Patient Health Questionnaire-2 (PHQ-2)], was the outcome variables. Chi-square tests and multivariable logistic regression models were used for statistical analyses.

Results: At least one depressive symptom was self-reported by 7.6% of uranium workers. Depressed mood was reported over twice as much as anhedonia (7.2% versus 3.3%). Abnormal FVC was associated with at least one depressive symptom after adjustment for covariates. There was no significant interaction between race/ethnicity and spirometric indices on depressive symptoms.

Conclusions: Although depressive symptoms are uncommonly reported in uranium workers, they are an important comorbidity due to their overall clinical impact. Abnormal FVC was associated with depressive symptoms. Race/ethnicity was not found to be an effect modifier for the association between abnormal FVC and depressive symptoms. To better understand the mechanism underlying this association and determine if a causal relationship exists between spirometric indices and depressive symptoms in occupational populations at risk for developing lung disease, larger longitudinal studies are required. We recommend screening for depressive symptoms for current and former uranium workers as part of routine health surveillance of this occupational cohort. Such screening may help overcome workers’ reluctance to self-report and seek treatment for depression and may avoid negative consequences to health and safety from missed diagnoses.

Introduction

Uranium workers are at risk of pulmonary injury via two primary mechanisms: inhalation of radon daughters causing radiation-induced lung damage (1,2) and dust inhalation (3). Exposed workers are additionally at risk for developing cardiovascular pathology (4). Lung diseases can result in a clinically significant decline in pulmonary function and have been associated with various neuropsychiatric sequelae (5,6). Screening for and treatment of depression in interstitial lung disease (ILD) has been proposed to improve quality of life (6-8). Significant levels of depressive symptoms are described in patients with silicosis (8) and may adversely affect quality of life (9). In a study of patients with ILD, depressive symptoms correlate with dyspnea, forced vital capacity (FVC), sleep quality, and pain (7).

Presence of depressed mood or anhedonia, which is a significant decrease in deriving pleasure from the majority of one’s daily activities, on most days, is requisite for diagnosis of major depressive disorder (10). Individual inquiry of depressed mood has demonstrated 85-90% sensitivity for detection of depression; and addition of another question, specific for anhedonia, raises overall sensitivity to 95% for the two-question inquiry (11).

Our objective was to evaluate the prevalence of depressive symptoms in uranium workers, to examine their association with spirometric values, and examine race/ethnicity interaction with spirometry on depressive symptoms. We studied uranium workers enrolled in the New Mexico Radiation Exposure Screening and Education Program (NM-RESEP). New Mexico workers have been significantly impacted by uranium extraction activities and many are compensated through the Radiation Exposure Compensation Act (RECA) (12). The findings from this study may help elucidate the biopsychosocial impact of uranium-related lung abnormalities in New Mexico workers.

Methods

Study Design:

This is a cross-sectional analysis of baseline evaluation data from former New Mexico uranium workers (i.e., miners, millers, and ore transporters) voluntarily enrolled between 2004 and 2017 in NM-RESEP, a federally-funded health-screening and education program, located at the University of New Mexico (UNM) Health Sciences Center, serving Albuquerque and surrounding communities.

Data Collection:

Data were obtained from a self-reported questionnaire administered by a trained interviewer and confirmed by a physician/nurse practitioner. The questionnaire included demographics, severity of dyspnea via the modified Medical Research Council (mMRC) Dyspnea Scale (13), information on smoking history, cardiovascular status, and screening for depressive symptoms (using the modified Patient Health Questionnaire or PHQ-2) which includes two items on depressed mood and anhedonia (14). Body mass index (BMI) was calculated using measured height and weight. A prebronchodilator spirometry was obtained by trained technicians, utilizing standard guidelines from the American Thoracic Society and the European Respiratory Society (15). Test results were independently reviewed for quality by a pulmonologist. Gender- and race/ethnicity- specific reference equations were used to determine predicted normative values for spirometry (16). Abnormal values were defined by the lower limit of normal obtained from reference standards. Data was entered into a secure web-based Research Electronic Data Capture (REDCap) database.

Predictor and Outcome Variables:

The outcome included a positive response for PHQ-2 item on either depressive symptom, i.e., depressed mood or anhedonia. Predictor variables included spirometric parameters and race/ethnicity, including the absolute and percent-predicted values for FVC), forced expiratory volume in one second (FEV1), and the absolute value of the FEV1/FVC ratio. Lower limits of normal obtained from the reference standards from the Third National Health and Nutrition Examination Survey (NHANES III) were used to define abnormal spirometric values (16).

Statistical Methods:

Frequencies, percentages, means, and standard deviations in a univariate analysis were reported. For the purpose of analyses, the outcome variable was endorsement of either depressive symptom. Chi-Square tests were used to analyze categorical outcome variables and generate p-values to determine significance of the findings. In the multivariable logistic regression analysis, variables that were evaluated for potential confounding included smoking status and pack-years.

Ethical Approval and Funding:

This study was approved by the UNM Institutional Review Board or Human Resources Protections Office (14-058). The study was supported by NM-RESEP, which is funded by the Health Resources Services Administration (HRSA), and UNM Health Science Center CTSC Grant Number: UL1TR001449.

Results

Subject characteristics are shown in Table 1. Of the 570 uranium workers, 97.1% were men, 66.7% were of racial/ethnic minority with the largest group being American Indian (36.6%). Most workers were older (mean age of 68.5 ± 8.1 years) with BMI values in the overweight or obese categories (82.1%). 7.6% of workers reported at least one depressive symptom, with 7.2% and 3.3% reporting depressed mood and anhedonia, respectively. The prevalence of at least one depressive symptom in Hispanic, American Indian, and non-Hispanic White workers were 11.4%, 7.2%, and 4.1%, respectively (p=0.14 for all race/ethnicity group comparison) and post-hoc comparison between Hispanic and non-Hispanic White workers was significant (p=0.001) (not shown in Table 1). 66.9% of workers were either former or current smokers. With regards to previous pulmonary history, 15.3% and 10.0% of workers reported positive history of COPD and asthma, respectively.

Table 1. NM-RESEP Uranium Workers (2004-2017).

Both unadjusted univariate and adjusted multivariable analyses revealed that workers with abnormal FVC were at least 2.9 times more likely to endorse at least one depressive symptom. No associations were found between abnormal FEV1 or abnormal FEV1/FVC ratios and depressive symptoms (Table 2).

Table 2. Unadjusted and Adjusted Associations of the Presence of Depressive Symptoms on Spirometric Indices.

*Covariates in the above multivariable model using logistic regression analysis included: smoking status and smoking pack-years. **Further adjustment for the following covariates: age, gender, and race/ethnicity did not change results in the multivariable model (FVC OR: 2.86, 95% CI: 1.18-6.96, p=0.02).

Although the associations between spirometric indices and depressive symptoms appeared stronger among Hispanic workers than other race/ethnicity subgroups, this was not borne by a formal test of interaction between race/ethnicity and spirometric indices on either depressive symptom. However, interaction testing identified a trend towards significance for Hispanic workers between abnormal FEV1 and self-reporting of depressive symptoms (p=0.07) (Table 3).

Table 3: Interaction between Spirometric Indices and Race/Ethnicity on Depressive Symptoms.

*Logistic regression analysis was used.

Discussion

A minority of uranium workers sampled in this secondary analysis self-reported at least one depressive symptom (7.6%). Depressed mood was reported over twice as much as anhedonia was reported (7.2% vs 3.3%). Abnormal FVC on spirometry was found to be associated with depressive symptoms after adjustment for covariates. There was no significant interaction between race/ethnicity and spirometric indices on depressive symptoms.

Uranium ore extraction in New Mexico occurs in open pit or underground mines. Subsequently, uranium is isolated from ore via milling or heap leaching (17). Most of the workers in this study were subjected to hazardous working conditions marked by lack of provision of personal protective equipment (including respirators) to handle uranium and inhalational dust exposure. Inadequate ventilation in underground mines also led to increased radon and dust exposure and workers were not adequately informed of these occupational exposures by mining companies or federal agencies (i.e. US Atomic Energy Commission, Nuclear Regulatory Commission, US Department of Energy) (12).

Uranium enters the human body primarily via inhalation and ingestion (18). It deposits primarily in the lungs and skeleton (insoluble uranium) and kidneys (soluble uranium) (19) where it causes chemical and radiological damage to these organs (20). In a murine study, uranium was found to enter the central nervous system, crossing the blood-brain barrier and accumulating in the hippocampus, resulting in detrimental neurophysiological effects and changes in REM sleep patterns (21). A case study involving 81 American Indian uranium workers found anxiety and depression to be the most common mental health problems, and respiratory complaints and skin rashes were the most common physical health issues (22). Radon gas, a byproduct of the uranium decay process, attaches to dust particles and when inhaled into the lungs the alpha radiation released by radon daughters damages lung tissue. Like non-uranium industry workers engaged in other types of mining-related activities, uranium workers are at risk for occupational pneumoconiosis, presenting with features similar to silicosis (23), and chronic fibrotic ILD (3). Pneumoconiosis has been associated with increased risk of other pulmonary conditions, including pulmonary emboli (24), lung carcinoma (23), chronic obstructive pulmonary disease (COPD) (26), tuberculosis (27), and clinically significant decline in lung function (28).

Many chronic pulmonary conditions such as asthma, COPD (29), bronchiectasis (30), and lung cancer (31) are associated with depressive symptoms. In a prospective study of patients with bronchiectasis, low FEV1 values were observed among patients with depressive symptoms (30). In a study of French dairy farmers, Guillien (32) found depression was associated with lower FEV1. A 2013 systematic review and meta-analysis revealed that the relationship between COPD and depression is bidirectional (33). Our study did not contain information regarding history of a prior or current diagnosis of depression for enrolled patients, thus our secondary analysis is not a like-for-like comparison to existing literature on this topic. Our study involved individuals with mostly normal lung function, indicating that the association between abnormal FVC and depressive symptoms may be seen relatively early in the disease course.

Psychosocial factors may play a role in the development of workplace-associated disability in workers with respiratory impairment, but evidence-based guidance to address these psychosocial factors is limited (34). The low prevalence of depressive symptoms in our study may reflect the high proportion of men enrolled (97.1%), as overall prevalence of depression in men is approximately half that of women (35). Alternatively, men may under-report due to a lack of awareness and understanding of depression and fear of stigmatization for self-reporting amongst coworkers or wider society. Additionally, use of the standard PHQ-2 and DSM diagnostic criteria in American Indians may not produce reliable results due to potential cultural and linguistic differences (36). The rate of depression in American indigenous populations has found to be 8.9% (which is higher than all other racial/ethnic groups except biracial individuals) and can range from 10-30% (37), however, the prevalence of depressive symptoms in American Indian workers in our study was 7.2%. To the best of our knowledge, no validation studies have been performed for use of any version of the PHQ-2 in New Mexican American Indian populations. The PHQ-2 has been validated in English- and Spanish-speaking Hispanic Americans (38). Perini found ethnic minorities diagnosed with “chronic nonspecific lung disease” exhibited higher absolute prevalence of depressive symptoms than the ethnic majority (29). Our study findings partially agree with Perini’s findings in that Hispanic uranium workers were more likely to endorse depressed mood than non-Hispanic White workers.

Our study was a cross-sectional, secondary analysis of an occupational cohort of mostly elderly, former uranium workers enrolled in NM-RESEP. Longitudinal analysis of this association may further elucidate the direction of the association. Our study could benefit from culture-specific depression diagnostic criteria paired with spirometric measures to specific pulmonary diagnoses. While anhedonia has customarily been associated with loss of pleasure (10), the construct has recently expanded to include interest in activity, effort, and discrimination between anticipation and consummatory forms of pleasure. New approaches for anhedonia assessment are in development (39). Our assessment of anhedonia may have been limited and a more robust screening tool that screens for additional depressive symptoms beyond depressed mood and anhedonia, such as the PHQ-9 or Hospital Anxiety and Depression Scale (HADS) rather than the PHQ-2, could improve result validity. As depression has a complex nature, a more rigorous biopsychosocial assessment would help in determining the role pulmonary pathology plays in depression in this study sample. To the best of our knowledge, this is the first study to examine the association of spirometric indices with depressive symptoms in former uranium workers. The strengths of our study include the robust participation of minority workers due to use of a mobile screening unit, its clinical relevance in light of ongoing uranium-associated activity, and potential future impact on health. Further study on this topic is merited as untreated depression in workers poses potential risks to workplace safety. As industrial use of nuclear material continues in the United States and other countries such as Kazakhstan, Canada, and Australia, this area of study is relevant to occupational health on a global scale. We recommend screening for depressive symptoms in current and former uranium workers as part of routine health surveillance to better address reluctance to self-report and seek treatment for depression, as well as to avoid potential negative consequences to health and safety from a missed diagnosis.

Acknowledgments

Guarantor: Akshay Sood MD, MPH takes responsibility for the content of the manuscript, including the data and analysis.

Author contributions: All authors had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. All authors contributed substantially to the data analysis and interpretation and the writing of the manuscript.

Financial/non-financial disclosures: All authors report no conflict of interest.

Abbreviation List

• BMI: body mass index
• COPD: chronic obstructive pulmonary disease
• CTSC: Clinical and Translational Science Center
• DSM: Diagnostic and Statistical Manual of Mental Disorders
• FEV1: forced expiratory volume in one second
• FVC: forced vital capacity
• HADS: Hospital Anxiety and Depression Scale
• ILD: interstitial lung disease
• mMRC: modified Medical Research Council
• NHANES III: The Third National Health and Nutrition Examination Survey
• NM-RESEP: New Mexico Radiation Exposure Screening and Education Program
• PHQ-2/PHQ-9: Patient Health Questionnaire-2/Patient Health Questionnaire-9
• RECA: Radiation Exposure Compensation Act
• REDCap: Research Electronic Data Capture
• UNM: University of New Mexico

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Cite as: Sharma S, Shore XW, Mohite S, Myers O, Kesler D, Vlahovich K, Sood A. Association between Spirometric Parameters and Depressive Symptoms in New Mexico Uranium Workers. Southwest J Pulm Crit Care. 2021;21(2):58-68. doi: https://doi.org/10.13175/swjpcc015-20 PDF 

Spirometry Use in Patients Prescribed Albuterol

Kevin Park, M.D.

Che' S. Ornelas, M.D.

Richard A. Robbins, M.D.

Phoenix VA Medical Center, Banner Good Samaritan VA Medical Center and the Phoenix Pulmonary and Critical Care Medicine and Research Foundation, Phoenix, AZ

Address correspondence to:     Richard A. Robbins, M.D.

                                             502 E. Vermont Drive

                                             Gilbert, AZ 85295

                                             E-mail: rickrobbins@cox.net

Conflict of Interest Statement: None of the authors have conflicts of interest pertinent to the subject matter of this manuscript. 

Abstract

Background:  Previous studies have shown that spirometry is obtained in only about a third of patients with chronic obstructive pulmonary disease (COPD) in primary care practice. This study evaluated spirometry use in persons prescribed an albuterol inhaler in the primary care clinics at a Veterans Administration (VA) hospital.

Methods: One hundred ninety-seven patients prescribed albuterol were reviewed for age, education level of the primary care practioners, other respiratory medications and diagnosis.

Results: The average age was 63.2 years (SD, 11.5), and 93% of patients were male. Obtaining spirometry was not age or sex-dependent but became more frequent with the use of tiotropium (72.2%), long-acting beta agonists (71.8%), ipratropium (69.4%)  or inhaled corticosteroids (63.5%) compared to albuterol alone (39.4%, p=0.0007). Eighty of the patients had a diagnosis of COPD (40.6%), 40 a diagnosis of asthma (20.3%), 23 other respiratory diagnoses (11.7%) but 54 (27.4%) had no respiratory diagnosis. Patients diagnosed with COPD were more likely to have spirometry performed (71.2%) than patients diagnosed with asthma (35%), other respiratory diagnosis (34.7%) or no respiratory diagnosis (40.7%) (p=0.00068).

Conclusions: The above data demonstrate that spirometry is more frequently used in patients with COPD than previously reported and increases when additional medications are added to albuterol.

Introduction

Spirometry is recommended for the diagnosis of most adult respiratory disease including chronic obstructive pulmonary disease (COPD) and asthma (1-5). However, previous publications have revealed that in patients with COPD spirometry is performed in only about a third of the patients (6-10). Based on this data, we initiated a quality improvement project to examine compliance with spirometry guidelines in primary care.

Most previous investigations have examined patients’ diagnosis of COPD or asthma and examined the percentage of patients who had spirometry. However, the diagnosis of COPD or asthma is frequently incorrect (11-13). Furthermore, these projects may likely both under- and over-diagnose COPD in patients with no symptoms (14). Since albuterol is recommended as initial treatment for both diseases (1-4), we examined recent prescriptions for albuterol at a single VA medical center. Our rationale was that this should eliminate asymptomatic patients or patients with very mild disease. We found that in patients prescribed albuterol who also had a diagnosis of COPD that spirometry was performed over double (72%) of previous reports.

Methods

This project was approved by the institutional review board of the Carl T. Hayden VA Hospital. Using VA records we identified 200 patients seen in primary care who were prescribed an albuterol inhaler and had a primary care visit between November 1-5, 2010 or November 8-12, 2010. The electronic records were reviewed for each patient. Demographic data (age, sex); education level of provider (MD or DO, nurse practioners); diagnosis (COPD, asthma, other respiratory diagnosis or no diagnosis); other respiratory medications, and the presence of spirometry were recorded. When spirometry was available for COPD patients, spirometric values of FEV1/FVC% or FEV1% predicted were recorded and used to classify COPD severity based on the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria (1,15).

Statistical Analysis

Comparisons between the groups with and without spirometry were made with χ2 tests for categoric variables and t tests for continuous variables. The association between having spirometry performed and patient characteristics was evaluated in unadjusted models.

Results

Chart review

Two hundred charts were examined, but 3 patients were excluded, one because they had not been prescribed albuterol and two because of incomplete data. The remaining 197 patients were evaluated.

Demographics

Age was 63+11 years and 7% of the patients were female. Age and sex were not significantly different between those who had spirometry and those who did not (data not shown, p>0.05 both comparisons).

Education Level of Provider

There were 16 MD or DO physician primary care providers and 8 nurse practioners. The physicians saw 136 patients and the nurse practioners 61. Spirometry was present on 73 of the patients seen by physicians (53.7%) and 29 of the patients seen by nurse practioners (47.5%, p=0.45).

Other Respiratory Medications

Numbers of patients with other respiratory medications are shown in Table 1. Many patients were on multiple medications. Patients on albuterol alone were significantly less likely to have spirometry than those on other medications (p=0.0007). Only two patients were receiving theophylline and one oral prednisone.

Table 1. Spirometry and other respiratory medications prescribed

LABA=Long-acting beta agonist

ICS=Inhaled corticosteroid

*p=0.0007 compared to other medications

Diagnosis

COPD was diagnosed in 80 patients (40.6%), asthma in 40 patients (20.3%), other respiratory diagnosis in 23 patients (11.7%) but no respiratory diagnosis was recorded in 54 patients (27.4%). Other respiratory diagnosis included 10 patients with tobacco dependence, 3 with dyspnea, 2 with lung carcinoma, and 2 with obstructive sleep apnea and one each with allergies, cannabis dependence, sinusitis, coin lesion, pulmonary embolus and respiratory disorder not otherwise specified. Patients with COPD were significantly more likely to have spirometry performed than other diagnosis (Table 2).

Table 2. Spirometry and respiratory diagnosis

*p=0.00068 compared to other diagnosis

Of the 57 patients with COPD and spirometry, 5 had very severe disease (FEV1 <30% predicted), 16 had severe disease (30% < FEV1< 50% predicted), 34 had moderate disease (50% < FEV1 < 80% predicted) and 2 had mild disease (FEV1>80% predicted) by GOLD criteria. Six of the 18 COPD patients without spirometry were receiving albuterol alone compared to 11 of the 57 of the COPD patients with spirometry (p=0.5519).

Discussion

The objective of this study was to examine spirometry use in primary care in patients with prescribed albuterol. Overall, the presence of spirometry in patients was low, with only 51.8% of patients having spirometry performed during the analysis period. Patients diagnosed with COPD or who had additional respiratory medications prescribed in addition to albuterol were more likely to undergo spirometry. In the present study, 71.8% of patients with COPD received spirometry.  This is more than twice the percentage of previous reports where only about a third of COPD patients had spirometry performed (6-10).

Spirometry is performed in some general medicine clinics, but in our hospital spirometry is performed in the pulmonary function laboratories or in the pulmonary clinic, a situation that may differ from many health-care systems. However, a previous report from a VA hospital reported only about a third of newly diagnosed COPD patients received spirometry (7). Our study differs in several aspects which might explain at least part of the variance. First, rather than looking at a diagnosis of COPD, we examined patients who were prescribed albuterol. This includes patients with asthma and other respiratory diagnosis. Second, we included patients with long-standing COPD rather COPD recently diagnosed. Previous reports suggest that as the number of visits increases that the likelihood of spirometry also increases (10). Third, many patients are “co-managed”, that is they received health care elsewhere in addition to the VA. It is entirely possible that they may have had spirometry performed elsewhere which is not available in our medical record. However, in contrast to previous studies, chart reviews were performed on each patient. If the patient had a previous spirometry recorded in the chart from another institution this should have been noted in our study. Fourth, the VA pharmacy placed restrictions on primary care physicians prescribing long-acting bronchodilators, especially tiotropium. These patients were usually referred to our pulmonary clinic where spirometry was usually required prior to referral.

Several factors have been previously identified that are related to lower rates of spirometry. Age had been reported as the factor with the most pronounced impact on decreasing the likelihood of undergoing spirometry in a VA population (6). However, we found no influence of age on the likelihood of spirometry performance. COPD diagnosis has also been reported to have a decreased likelihood of spirometry performance (8), but in contrast, we found that COPD actually increased the likelihood of spirometry performance. The use of theophylline has also been associated with decreased levels of spirometry performance. However, only about 1% of our patients were prescribed theophylline.

There are several limitations to our study. First, it is a single site study. It is possible that our primary care physicians are more likely to order spirometry because of increased awareness or restrictions in prescribing long-acting bronchodilators or referral to a pulmonary clinic. Previous reports from the VA have demonstrated that there is a large geographic variation in the use of spirometry to diagnose COPD (8). The location of the present study was in Veterans Integrated Service Network 18 (Arizona, New Mexico and West Texas) where spirometry use (36.9%) approximated the National mean (36.7%). It is unclear whether the results from the present study can be generalized to the VA as a whole or non-VA institutions is unclear. Second, we examined patients prescribed an albuterol inhaler rather than those with a diagnosis of COPD or asthma. This likely eliminates many patients with mild or no symptoms which differs from previous studies. The US Preventive Services Task Forces has recommended against screening asymptomatic patients with spirometry (16).

The patients with no diagnosis given albuterol were a heterogenous group and the indications for the use of albuterol were often absent or unclear. Although albuterol can be empirically prescribed for asthma, cough or COPD, the indications for albuterol were absent in the majority of charts.

This study suggests that in contrast to previous reports, much of the current COPD diagnosis and management is based on spirometric evidence of airway obstruction in addition to symptoms. Although the role of spirometry in routine clinical practice remains unclear, primary care providers at our VA hospital appear to frequently use spirometry in patients with COPD.

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Reference as: Park K, Ornelas CS, Robbins RA. Spirometry use in patients prescribed albuterol. Southwest J Pulm Crit Care 2011;4:25-9. (Click here for a PDF version of the manuscript)