Focus on Asthma and COPD
Issue 4
November 2011

Tools for Diagnosis and Assessment of Asthma and Chronic Obstructive Pulmonary Disease in Clinical Practice

Gabriel Ortiz

Gabriel Ortiz

Pediatric Pulmonary Services,
El Paso, Texas

Gabriel Ortiz serves as the American Academy of Physician Assistants (AAPA) liaison to the American Academy of Allergy Asthma and Immunology (AAAAI) and as the AAAAI liaison to the AAPA. He has served previously as the AAPA liaison to the National Asthma Education and Prevention Program.

Other articles by the same author in this e-newsletter series:

Summary Information for Inhaled Corticosteroid and Long-Acting β2-Adrenergic Agonist Combination Product Use in Patients in the United States Who Have Asthma or Chronic Obstructive Pulmonary Disease.

Available at:

Applying the 2009 Global Initiative for Chronic Obstructive Lung Disease (GOLD) Guidelines for the Pharmacological Management of Chronic Obstructive Pulmonary Disease in Clinical Practice.

Available at:

The Importance of Accurate Obstructive Respiratory Disease Diagnoses: A Comparison of Asthma and Chronic Obstructive Pulmonary Disease.

Available at:

Key Points

  • A detailed medical history and physical examination can identify patients who may have asthma or chronic obstructive pulmonary disease (COPD). The diagnosis of asthma or COPD should be confirmed with spirometry.
  • Asthma diagnosis in children younger than 5 years is based primarily on symptoms and a therapeutic trial of medications; it may be difficult to perform spirometry with patients in this age group.
  • Spirometry is valuable to track lung function over time in patients with asthma or COPD.
  • Validated questionnaires are helpful tools to screen for COPD and asthma, assess the effect of asthma or COPD on a patient’s health status and quality of life, and measure disease control.
Case Study

J.L. is a 15-year-old girl who lives in the suburban Northeast and attends high school. She has a history of seasonal allergic rhinitis, which is treated on an as-needed basis. She presents to her health care practitioner (HCP) with a chief complaint of coughing that is most bothersome at night. Her mother expresses concern that she is not as interested in playing field hockey as she was in previous years. Her HCP asks more probing questions about her exercise tolerance, and J.L. states that she sometimes feels short of breath while running with the team. Her HCP suspects the presence of airway obstruction based on her medical history and symptoms.


Asthma and COPD are the most common obstructive respiratory diseases, affecting approximately 24.6 and 12 million people in the United States, respectively [1, 2]. The burden of these diseases on the health care system is substantial. In 2010, national projected annual costs for asthma were $20.7 billion and those for COPD were $49.9 billion [2-4]. The National Asthma Education and Prevention Program (NAEPP) and the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines recommend the use of physical examination, medical history, and spirometry for the diagnosis of asthma or COPD [5, 6]. Despite these recommendations, evidence suggests that patients with clinically important lung disease are either undiagnosed or misdiagnosed [6-8]. Establishing an accurate diagnosis of obstructive lung disease leads to the appropriate use of medications that can improve symptom control, lung function, and quality of life in patients [8]. Tools for diagnosing and assessing asthma and COPD used in primary care, specialty practice, or clinical asthma or COPD trials are discussed in this newsletter.

Tools for Diagnosing Asthma

The diagnosis of asthma is based on establishing airflow obstruction that is at least partially reversible [6]. Medical history, physical examination, and spirometry are the tools used to make an accurate asthma diagnosis. A detailed medical history for a patient suspected of having asthma should address symptoms and their pattern of occurrence; precipitating or aggravating factors; exacerbation type, severity, and frequency; family history; social history; and patient’s assessment of illness [6]. The key indicators of asthma include symptoms of wheezing, difficulty in breathing, chest tightness, and cough, which may be particularly worse at night [6]; in children, chronic night cough is considered a “variant” of asthma and may be caused by bronchoconstriction or excessive mucus [9]. Asthma symptoms should be recurrent and may worsen in the presence of exercise, viral infection, or exposure to allergens, such as animal fur or hair, dust mites, mold, smoke, pollen, or airborne chemicals. Physical examination should be focused on abnormalities of the nose, throat, upper airway, chest, and skin [6].

Spirometry is recommended to establish the diagnosis of asthma, characterize the degree of airflow obstruction, assess reversibility, and exclude other diagnoses [6]. The basics of spirometry are reviewed in a module that is available at Spirometry measures the amount of air exhaled during the first second (forced expiratory volume in 1 second [FEV1]) and the maximum volume of air that is exhaled (forced vital capacity [FVC]) [6]. The FEV1 is reported as the absolute value (L) and as a percentage of predicted reference values based on age, height, sex, and race [10]. In asthma, clinically significant reversibility is defined as an increase in FEV1 of ≥12% and >200 mL from baseline (pre- to postbronchodilator) [6, 11] after administration of an inhaled short-acting bronchodilator [6]. Asthma is usually associated with reversibility of airflow limitation after bronchodilator administration; however, spirometric findings must be combined with history for an accurate diagnosis [6].

Case Study Continued

J.L. performs spirometry, which yields the following results: prebronchodilator FEV1 = 73% predicted and postbronchodilator FEV1 = 85% predicted. Her postbronchodilator FEV1 value increased by ≥12% and >200 mL from baseline, suggesting significant bronchodilator reversibility [10]. Based on these results and her symptoms, J.L. is diagnosed with asthma and starts appropriate treatment based on the NAEPP guidelines.

In children younger than 5 years of age, asthma diagnosis is guided by history, symptoms, physical examination, and quality of life assessment [6]. The symptoms of wheeze and cough are highly nonspecific, and lung function tests are unreliable in this age group to rule out alternate diagnoses, which commonly include viral respiratory infections and gastroesophageal reflux disease [6, 12]. A therapeutic trial of medication may assist in the diagnosis [6]. The Modified Asthma Predictive Index (mAPI) is a simple tool that has been developed to identify children 2 or 3 years of age with recurrent wheeze and who are likely to experience improvements in symptoms and exacerbations with daily inhaled corticosteroid therapy [13-15]. The original asthma predictive index (API) assesses the likelihood of a child with frequent wheezing in the first 3 years of life developing symptoms of persistent asthma at school age [16] and may be a useful tool for primary care. Differences between the original API and the mAPI are outlined in Table 1.

Table 1. The Modified Asthma Predictive Index vs the Original Asthma Predictive Index [13, 14, 16]

The child must have a history of ≥ 4 wheezing episodes during the previous 12 months, with ≥ 1 episode confirmed by a physician. In addition, the child must meet ≥ 1 of the following major criteria or ≥ 2 of the minor criteria.
mAPI: Major criteria Original API: Major criteria
  • Parental history of asthma
  • Physician-diagnosed atopic dermatitis
  • Allergic sensitization to ≥ 1 aeroallergen
  • Parental history of asthma
  • Physician-diagnosed atopic dermatitis
mAPI: Minor criteria Original API: Minor criteria
  • Allergic sensitization to milk, egg, or peanuts
  • Wheezing unrelated to colds
  • Blood eosinophils ≥ 4%
  • Physician-diagnosed allergic rhinitis
  • Wheezing unrelated to colds
  • Blood eosinophils ≥ 4%

Differences are in bold.

Adapted with permission from Elsevier. Copyright 2004 [13].

Measurement of the fraction of exhaled nitric oxide (FeNO) has been studied as a diagnostic tool for asthma [17]. NO plays a role in regulating airway function, and FeNO concentration is considered a surrogate for airway inflammation [18, 19] and is also known to increase during asthma exacerbations [18]. FeNO measurements are quick and easy to take, making them attractive for use in children [20]. In the 10-year follow-up of a prospective birth cohort study in Oslo (n = 331), increased FeNO concentrations differentiated children with allergic asthma from those with asthma in remission or nonallergic asthma [21]. In a study of 150 school-aged children with symptoms of asthma, FeNO was better than FEV1 in identifying children with asthma [19]. Despite these findings, community-based studies of FeNO as a diagnostic test have produced conflicting results, with the identification of allergic disease as a major confounding factor [20]. Thus, measurement of FeNO is an emerging tool for the diagnosis of asthma [6, 19]. The American Thoracic Society recently published guidelines for interpretation of FeNO for clinical applications, and particularly recommends it for diagnosis of eosinophilic airway inflammation [22].

Tools for Diagnosing COPD

The clinical manifestations of COPD are variable and often complicated by comorbid conditions [5]. Patients may attribute their respiratory symptoms to another disease, aging, or simply lack of exercise. Screening tools are recommended to help identify patients with respiratory symptoms—particularly progressive or persistent dyspnea, chronic cough, and chronic sputum production—who may have COPD [5]. In addition to symptomatic patients, screening for COPD is recommended for healthy adults who are aged 40 years or older, current or former smokers, and those with a history of exposure to environmental risk factors [23]. Two validated screening tools are available [24]: the Lung Function Questionnaire (LFQ) [25] and the COPD Population Screener (COPD-PS) questionnaire [26]. Both tools have 5 questions related to a patient’s smoking history, age, and symptoms, and can be completed independently by patients. The COPD-PS is available in English and Spanish through the COPD Alliance at [21]. Patients who score ≥ 5 [26] on the COPD-PS or ≥ 3 on the LFQ [25] are at risk for airflow obstruction and should undergo full pre-and postbronchodilator spirometry testing according to established guidelines [4, 5] to confirm a diagnosis of COPD. Caucasian patients who develop COPD at <45 years of age also should be screened for alpha-1 antitrypsin deficiency [5].

COPD is characterized by airflow limitation that is not fully reversible, recorded on spirometry as a postbronchodilator FEV1/FVC < 0.70 [5]. Spirometry also is useful in determining the severity of illness, differentiating between asthma and COPD, and monitoring response to treatment as reviewed in the third article in this series (click to view: The third issue of this series also reviews the simple 4-item questionnaire developed by Beeh et al to assist HCPs in differentiating between asthma and COPD (Click here to view Issue 3, Table 2) [27]. Total scores range from 0 to 15; higher scores support a diagnosis of COPD and lower scores support a diagnosis of asthma.

Once a diagnosis has been made and the severity of disease defined, treatment recommendations should be based on national guidelines as reviewed in the first article for asthma and COPD (click to view: and the second article for COPD (click to view: Once asthma or COPD has been diagnosed, HCPs need to continue to monitor and assess disease control. This newsletter continues with a discussion of available assessment tools.

Tools for Assessment of Asthma

The pathological process of asthma varies over time, underscoring the need for routine assessment of disease control and response to treatment [6]. Tools used to assess asthma control include standardized questionnaires (eg, Asthma Control Test [ACT], Asthma Control Questionnaire [ACQ], and Asthma Therapy Assessment Questionnaire [ATAQ]) and spirometry, including forced expiratory volumes and flows [6]. Asthma control is determined by reviewing current levels of impairment—pulmonary function, asthma symptoms, use of quick-relief medication, and the effect of asthma on physical activity and quality of life—and the patient’s risk for exacerbations [6]. Characteristics of well-controlled asthma by age group are presented in Table 2.

Table 2. Characteristics of Well-Controlled Asthma by Age Group [6, 28-30]

of Control
Children Aged
0 to 4 Years
Children Aged
5 to 11 Years
Youth Aged
≥ 12 Years and Adults
Symptoms ≤ 2 days/week ≤ 2 days/week, but not more than once on each day ≤ 2 days/week
Nighttime awakenings ≤ 1 time/month ≤ 1 time/month ≤ 2 times/month
Interference with normal activities None None None
Short-acting β2-agonist use for symptom control (not exercise-induced bronchospasm) ≤ 2 days/week ≤ 2 days/week ≤ 2 days/week
Lung function as assessed by spirometry (FEV1) or peak flow NA > 80% predicted or personal best
FEV1/FVC > 80%
> 80% predicted or personal best
Validated Questionnaires
C-ACT or ACT NA C-ACT ≥ 20a ACT ≥ 20
TRACK ≥ 80a,b NA NA
ACQ NA NAa ≤ 0.75a
Exacerbations 0–1 per year 0–1 per yearc 0–1 per yearc

ACQ, Asthma Control Questionnaire; ACT, Asthma Control Test; ATAQ, Asthma Therapy Assessment Questionnaire; C-ACT, Childhood Asthma Control Test; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; TRACK, Test for Respiratory and Asthma Control in Kids.

aThe C-ACT and TRACK are relatively new instruments and are not included in the NAEPP guidelines; the ACQ and ATAQ also are not included in the NAEPP guidelines for patients aged 5 to 11 years. ACQ values of 0.76–1.4 are indeterminate regarding well-controlled asthma.

bTRACK has been developed and validated for assessing control in children < 5 years of age only.

cConsider severity and interval since last exacerbation. There are inadequate data to correlate the frequency of exacerbations with the level of asthma control. In general, more frequent and intense exacerbations indicate poorer disease control. Patients with ≥ 2 exacerbations requiring oral systemic corticosteroids in the past year should be considered to have not-well-controlled asthma.

  • The level of control is based on the most severe component. The patient’s or caregiver’s recall of the components of control should be based on the previous 2 to 4 weeks.
  • Medication side effects should be considered in the assessment of risk for adverse outcomes. The level of intensity of side effects does not correlate with specific levels of asthma control.

ACT is a reliable and validated measure of asthma control for patients aged 12 years and older (Table 3) [6, 32, 33]. The 5-item questionnaire measures key elements of asthma control, including daytime and nighttime symptoms and the effect of asthma on daily activities [6, 32]. A score of 20 or higher indicates that asthma is well controlled (Table 2) [6, 28]. A version of the ACT has been developed and validated for children aged 4 to 11 years (Childhood ACT [C-ACT]) [28]. The ACT and C-ACT are easy for patients to access (Table 3 provides links). For children younger than 5 years who have symptoms consistent with asthma, the Test for Respiratory and Asthma Control in Kids (TRACK) has been developed and validated for assessing control (Table 3) [29, 30]. This 5-question tool can be completed by caregivers at home or in the waiting room, and interpreted by the child’s HCP. A score of < 80 on TRACK suggests that a child has uncontrolled respiratory or asthma symptoms [29, 30].

Table 3. Select Tools Available to Assist in the Assessment of Asthma or Chronic Obstructive Pulmonary Disease (COPD)

Tool Acronym Link
Asthma Control Test
(aged ≥ 12 years)
Childhood Asthma Control Test
(aged 4 to 11 years)
Asthma Control Questionnaire ACQ
Asthma Therapy Assessment Questionnaire (aged 5–17 years) ATAQ Pediatric/
Asthma Therapy Assessment Questionnaire (aged ≥ 18 years) ATAQ Adult
Test for Respiratory and Asthma Control in Kids
(aged < 5 years)
Clinical COPD Questionnaire CCQ
Medical Research Counsel Dyspnea MRC-D
St. George’s Respiratory Questionnaire SGRQ

The ACQ is an instrument validated for measuring asthma control for patients aged ≥ 6 years [34-36]. The questionnaire assesses the patient’s experience over the past week via 7 questions (the patient or guardian answers 6 questions, the HCP answers 1 question) on a 7-point scale. The mean of the 7 items is the ACQ score, with 0 = well controlled and 6 = extremely poorly controlled [34, 35]. The ATAQ, developed to assess the level of disease control and for use in disease management, is a validated questionnaire that adults can self-administer [37, 38]. The instrument consists of questions relating to the patient’s past month of asthma control and is scored on a scale of 0–4 [37, 38], with a higher score meaning more control issues. Both tools are available in interviewer-administered versions for younger patients [35, 39]. The ACQ and ATAQ are longer questionnaires than the ACT, and may be inconvenient for use in primary care.

J.L. returns for a routine follow-up examination and her HCP has her complete the 5-item ACT. Her score is 17 and her answers reveal that she is still having symptoms of shortness of breath and cough. These symptoms awaken her at night once a week. She also confides to her HCP that she has smoked occasionally with friends. Her overall rating of asthma control is "somewhat controlled."

J.L.'s HCP discusses the effect of smoking and other potential aggravating factors on asthma and asks about her exercise tolerance. The HCP makes adjustments to her medications, provides her with a written asthma action plan, and requests additional follow-up in 3 to 4 weeks.

HCPs should develop a written asthma action plan for at-home self-monitoring for all patients, especially those with moderate or severe persistent asthma, a history of severe exacerbations, or poorly controlled asthma. Children also should receive an action plan catered to their school setting [6]. These plans encourage patient awareness of disease status and control by providing instructions for daily symptom-based monitoring, peak flow meter monitoring, or a combination of both. Results from randomized controlled trials in patients with asthma have shown that self-management of asthma, including action plans, resulted in fewer days of restricted activity, [40] improved adherence to therapy with inhaled corticosteroids, [41] and increased asthma control [40, 41] compared with usual care. Peak flow–based monitoring is recommended for patients with moderate or severe persistent asthma, a history of severe exacerbations, or poor perception of airflow obstruction [6]. However, patients should be able to effectively use the meters or measurements, which are dependent on effort and technique [6] and may therefore be inaccurate. Action plans should include instructions for handling acute symptoms (or changes in peak expiratory flow) through self-adjustment of medications, and for identifying when an HCP should be contacted [6]. Patients should be instructed to seek medical care early if the exacerbation is severe, the treatment does not provide quick and sustained results, or the exacerbation worsens [6]. Example asthma action plans for children and adults are provided by the National Asthma Education and Prevention Program of the National Heart, Lung, and Blood Institute in the Expert Panel Report 3 ( See Section 3, Component 2, Figures 3–10a–c.) [6]

Long-term daily peak flow monitoring is recommended for the patients with moderate to severe persistent asthma, and also can be helpful to detect early changes in disease states, evaluate responses to therapy changes, and measure impairment [6]. However, spirometry is recommended for asthma monitoring when there is ongoing or progressive loss of asthma control and should be used to track lung function at a minimum of every 1 to 2 years [6]. Older patients and those who have severe exacerbations may not recognize symptoms of airflow obstruction, and therefore may be candidates for more frequent spirometry [6].

Tools for Assessment of COPD

The phrase “preventable and treatable” has been added to the definition of COPD in the updated GOLD guidelines to provide a positive outlook for patients and encourage HCPs to effectively manage the disease [5]. Routine monitoring enables HCPs to adjust therapy and identify complications [5]. Yearly measurement of lung function with spirometry is useful to track disease progression [5], especially because patients may only report severe symptoms and impairment or may adapt their lifestyles to subtle changes in symptoms [42]. However, if a substantial increase in symptoms is observed or complications are identified, spirometry should be performed at that time. As COPD progresses, other measurements may include diffusing capacity, lung volumes, arterial blood gases, and pulmonary hemodynamics [5]. Appropriate imaging techniques may be used to exclude differential diagnoses, to establish the presence of significant comorbidities, and to evaluate the distribution of emphysema [5].

Several questionnaires or wellness tools have been developed to assess respiratory symptoms and disability in COPD and are recommended for use by the International Primary Care Respiratory Group (IPCRG) [31]. The IPCRG has rated 9 tools based on the following 6 criteria: (1) validity (ie, does it measure what it intends to measure?) and reliability (ie, is the measurement reproducible?), (2) responsiveness (ie, does it respond to changes in the patient’s condition?), (3) applicability to the primary care population with the full range of COPD, (4) practicality and ease of administration, (5) tested in practice, and (6) availability in other languages. A full description of these criteria, how each tool ranks, and where HCPs can access the tool can be found on their website (

Of the tools ranked by the IPCRG, the Clinical COPD Questionnaire (CCQ) was the only instrument to receive a “highly recommended” rating for all 6 criteria. The CCQ measures disease-related health status in patients with COPD to help patients and practitioners understand symptom severity and disease limitations [31]. Patients respond to 10 items based on their previous week’s symptoms. Higher scores represent worse health status and have been associated with frequent symptoms of chest tightness, persistent colds, cough, sleeping problems, and fatigue [43]. The CCQ can be scored online and printed (see Table 3). The Medical Research Council Dyspnea (MRC-D) scale also was highly recommended for primary care. The MRC-D contains 5 statements that describe varying degrees of breathlessness (Table 4) [43, 44]. The MRC-D is validated to quantify disability associated with dyspnea and correlates with lung function measurements and walking distance [44].

Table 4. Medical Research Council Dyspnea (MRC-D) Scale for Assessment of COPD [44].

Grade Degree of Breathlessness Related to Activities
1 Not troubled by breathlessness except on strenuous exercise
2 Short of breath when hurrying on the level or walking up a slight hill
3 Walks slower than most people on the level, stops after a mile or so, or stops after 15 minutes walking at own pace
4 Stops for breath after walking about 100 yards or after a few minutes on level ground
5 Too breathless to leave the house, or breathless when undressing

Reproduced with permission from Oxford University Press [44].

The St. George’s Respiratory Disease Questionnaire (SGRQ) is a more extensive quality of life instrument that provides domain scores for symptoms, activity, and psychosocial impact and a total score [31]. The instrument takes about 10 minutes to complete and contains 76 items [45]. The domain and total scores are calculated based on weighted responses, with scores range from 0 to 100 (0 [no impairment] and 100 [ worst possible impairment]) [46]. In patients with COPD, SGRQ has been shown to have varying degrees of association with symptoms, lung function measurements [45], frequency of exacerbations [47, 48], and hospital readmission [49]. This tool is frequently used in clinical trials of patients with COPD, particularly the symptom domain [31]; the length of the instrument may make it inconvenient for regular use in primary care, particularly for patients who are elderly or who may otherwise have difficulty concentrating.

The ATS also provides an online resource for tools that have been used in the assessment of patients with pulmonary disease ( These instruments assess quality of life, health-related quality of life, or functional status. To be included on the ATS site, information regarding the instrument’s development, reliability, validity, and use in patients with pulmonary disease or critical illness must be published in the peer-reviewed literature [50].


The airflow obstruction of asthma or COPD leads to symptoms of cough, shortness of breath, and, in COPD particularly, sputum production. Findings on physical examination and review of medical history also can indicate asthma or COPD, but the diagnosis of these diseases is dependent on the results of spirometry. For asthma, a reversible airflow obstruction is defined as an increase in FEV1 ≥12% and >200 mL from baseline after bronchodilator administration (pre- to postbronchodilator maneuver). For COPD, postbronchodilator spirometry recordings of FEV1/FVC < 0.70 are diagnostic. Routine monitoring of these diseases can be achieved with a number of tools, including questionnaires, asthma action plans, peak expiratory flow, and spirometry. Use of these assessment tools helps to achieve treatment goals, track pulmonary function over time, and monitor disease control or health status.

Acknowledgements and Disclosures

Gabe Ortiz has served on the COPD advisory board for Boehringer Ingelheim and Pfizer; has attended the COPD Alliance Steering Committee Meeting for American Academy of Physician Assistants; is a consultant to Dey, Merck, Sunovion, and Teva; and is on the speakers’ bureaus of Genentech, Merck, Phadia United States, and Teva. He received writing assistance from Marissa Buttaro, MPH, from Scientific Connexions (Newtown, PA) and Michelle McDermott, PharmD, through funding from AstraZeneca LP (Wilmington, DE).


  1. Akinbami LJ, Moorman JE, Liu X. Asthma prevalence, health care use, and mortality: United States, 2005–2009. Natl Health Stat Rep. 2011;32:1-14.
  2. American Lung Association. Trends in COPD (Chronic Bronchitis and Emphysema): Morbidity and Mortality. February 2010. Accessed February 21, 2011.
  3. American Lung Association. Trends in Asthma Morbidity and Mortality. February 2010. Accessed February 21, 2011.
  4. Celli BR, MacNee W; ATS/ERS Task Force. Standards for the diagnosis and treatment of patients with COPD: a summary of the ATS/ERS position paper. Eur Respir J. 2004;23(6):932-946.
  5. Global Initiative for Chronic Obstructive Lung Disease. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease. 2010. Accessed June 20, 2011.
  6. National Heart, Lung, and Blood Institute, National Asthma Education and Prevention Program. Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma—Full Report 2007. NIH Publication Number 08-4051, 2007.
  7. American Lung Association. Chronic Obstructive Pulmonary Disease Fact Sheet. February 2011. Accessed June 19, 2001
  8. Tinkelman DG, Price DB, Nordyke RJ, Halbert RJ. Misdiagnosis of COPD and asthma in primary care patients 40 years of age and over. J Asthma. 2006;43(1):75-80.
  9. Toop LJ, Howie JGR, Paxton FM. Night cough and general practice research. J R Coll Gen Pract. 1986;36:74-77.
  10. American Thoracic Society. Lung function testing: selection of reference values and interpretive strategies. Am Rev Respir Dis. 1991;144(5):1202-1218.
  11. Pellegrino R, Viegi G, Brusasco V, Crapo RO, Burgos F, Casaburi R, Coates A, van der Grinten CP, Gustafsson P, Hankinson J, Jensen R, Johnson DC, MacIntyre N, McKay R, Miller MR, Navajas D, Pedersen OF, Wanger J. Interpretative strategies for lung function tests. In: Brusasco V, Crapo R, Viegi G, series eds. ATS/ERS Task Force: standardisation of lung function testing. Number 5 in the series. Eur Respir J. 2005;26(5):948-968.
  12. Levy ML, Fletcher M, Price DB, Hausen T, Halbert RJ, Yawn BP. International primary care respiratory group (IPCRG) guidelines: diagnosis of respiratory diseases in primary care. Prim Care Respir J. 2006;15(1):20-34.
  13. Guilbert TW, Morgan WJ, Zeiger RS, Bacharier LB, Boehmer SJ, Krawiec M, Larsen G, Lemanske RF, Liu A, Mauger DT, Sorkness C, Szefler SJ, Strunk RC, Taussig LM, Martinez FD. Atopic characteristics of children with recurrent wheezing at high risk for the development of childhood asthma. J Allergy Clin Immunol. 2004;114(6):1282-1287.
  14. Guilbert TW, Morgan WJ, Krawiec M, Lemanske RF Jr, Sorkness C, Szefler SJ, Larsen G, Spahn JD, Zeiger RS, Heldt G, Strunk RC, Bacharier LB, Bloomberg GR, Chinchilli VM, Boehmer SJ, Mauger EA, Mauger DT, Taussig LM, Martinez FD; Prevention of Early Asthma in Kids Study, Childhood Asthma Research and Education Network. The Prevention of Early Asthma in Kids study: design, rationale and methods for the Childhood Asthma Research and Education network. Control Clin Trials. 2004;25:286-310.
  15. Guilbert TW, Morgan WJ, Zeiger RS, Mauger DT, Boehmer SJ, Szefler SJ, Bacharier LB, Lemanske RF Jr, Strunk RC, Allen DB, Bloomberg GR, Heldt G, Krawiec M, Larsen G, Liu AH, Chinchilli VM, Sorkness CA, Taussig LM, Martinez FD. Long-term inhaled corticosteroids in preschool children at high risk for asthma. N Engl J Med. 2006;354(19):1985-1997.
  16. Castro-Rodríguez JA, Holberg CJ, Wright AL, Martinez F. A clinical index to define risk of asthma in young children with recurrent wheezing. Am J Respir Crit Care Med. 2000;162(4 pt 1):1403-1406.
  17. Reddel HK, Taylor DR, Bateman ED, Boulet LP, Boushey HA, Busse WW, Casale TB, Chanez P, Enright PL, Gibson PG, de Jongste JC, Kerstjens HA, Lazarus SC, Levy ML, O'Byrne PM, Partridge MR, Pavord ID, Sears MR, Sterk PJ, Stoloff SW, Sullivan SD, Szefler SJ, Thomas MD, Wenzel SE; American Thoracic Society/European Respiratory Society Task Force on Asthma Control and Exacerbations. An official American Thoracic Society/European Respiratory Society Statement: asthma control and exacerbations: standardizing endpoints for clinical asthma trials and clinical practice. Am J Respir Crit Care Med. 2009;180(1):59-99.
  18. Barnes PJ, Dweik RA, Gelb AF, Gibson PG, George SC, Grasemann H, Pavord ID, Ratjen F, Silkoff PE, Taylor DR, Zamel N. Exhaled nitric oxide in pulmonary diseases: a comprehensive review. Chest. 2010;138(3):682-692.
  19. Sivan Y, Gadish T, Fireman E, Soferman R. The use of exhaled nitric oxide in the diagnosis of asthma in school children. J Pediatr. 2009;155(2):211-216.
  20. Turner S. The role of exhaled nitric oxide in the diagnosis, management and treatment of asthma. Mini Rev Med Chem. 2007;7(5):539-542.
  21. Sachs-Olsen C, Lødrup Carlsen KC, Mowinckel P, Håland G, Devulapalli CS, Munthe-Kaas MC, Carlsen KH. Diagnostic value of exhaled nitric oxide in childhood asthma and allergy. Pediatr Allerg Immunol. 2010;21(1 pt 2):e213-e221.
  22. Dweik RA, Boggs PB, Erzurum SC, Irvin CG, Leigh MW, Lundberg JO, Olin AC, Plummer AL, Taylor DR on behalf of the American Thoracic Society Committee on Interpretation of Exhaled Nitric Oxide Levels (FeNO) for clinical applications. An official ATS clinical practice guideline: interpretation of exhaled nitric oxide levels (FeNO) for clinical applications. Am J Respir Crit Care Med. 2011;184(5):602-615.
  23. U.S. Preventive Services Task Force. Screening for chronic obstructive pulmonary disease using spirometry: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2008;148(7):529-534.
  24. COPD Alliance. Online COPD Screener. Accessed February 21, 2011.
  25. Yawn BP, Mapel DW, Mannino DM, Martinez FJ, Donohue JF, Hanania NA, Kosinski M, Rendas-Baum R, Mintz M, Samuels S, Dalal AA; Lung Function Questionnaire Working Group. Development of the lung function questionnaire (LFQ) to identify airflow obstruction. Int J Chron Obstruct Pulmon Dis. 2010;5:1-10.
  26. Martinez FJ, Raczek AE, Seifer FD, Conoscenti CS, Curtice TG, D'Eletto T, Cote C, Hawkins C, Phillips AL; COPD-PS Clinician Working Group. Development and initial validation of a self-scored COPD Population Screener Questionnaire (COPD-PS).
    COPD. 2008;5(2):85-95.
  27. Beeh KM, Kornmann O, Beier J, Ksoll M, Buhl R. Clinical application of a simple questionnaire for the differentiation of asthma and chronic obstructive pulmonary disease. Respir Med. 2004;98(7):591-597.
  28. Liu AH, Zeiger R, Sorkness C, Mahr T, Ostrom N, Burgess S, Rosenzweig JC, Manjunath R. Development and cross-sectional validation of the Childhood Asthma Control Test. J Allergy Clin Immunol. 2007;119(4):817-825.
  29. Murphy KR, Zeiger RS, Kosinski M, Chipps B, Mellon M, Schatz M, Lampl K, Hanlon JT, Ramachandran S. Test for Respiratory and Asthma Control in Kids (TRACK): a caregiver-completed questionnaire for preschool-aged children. J Allergy Clin Immunol. 2009;123(4):833-839.
  30. Chipps B, Zeiger RS, Murphy K, Mellon M, Schatz M, Kosinski M, Lampl K, Ramachandran S. Longitudinal validation of the Test for Respiratory and Asthma Control in Kids in pediatric practices. Pediatrics. 2011;127(3):e737-47.
  31. International Primary Care Respiratory Group. IPCRG user’s guide to COPD “wellness” tools. Accessed June 17, 2011.
  32. Nathan RA, Sorkness CA, Kosinski M, Schatz M, Li JT, Marcus P, Murray JJ, Pendergraft TB. Development of the Asthma Control Test: a survey for assessing asthma control. J Allergy Clin Immunol. 2004;113(1):59-65.
  33. Schatz M, Sorkness CA, Li JT, Marcus P, Murray JJ, Nathan RA, Kosinski M, Pendergraft TB, Jhingran P. Asthma Control Test: reliability, validity, and responsiveness in patients not previously followed by asthma specialists. J Allergy Clin Immunol. 2006 Mar;117(3):549-556.
  34. Juniper EF, O’Byrne PM, Guyatt GH, Ferrie PK, King DR. Development and validation of a questionnaire to measure asthma control. Eur Respir J. 1999;14(4):902-907.
  35. Juniper EF, Gruffydd-Jones K, Ward S, Svensson K. Asthma Control Questionnaire in children: validation, measurement properties, interpretation. Eur Respir J. 2010;36(6):1410-1416.
  36. Juniper E, Gruffydd-Jones K, Ward S, Thomas M. Developing an interviewer-administered version of the asthma control questionnaire (ACQ) for children ≤10 years [abstract]. Poster presented at: the European Respiratory Society (EAC); September 17, 2007; Stockholm, Sweden. Available at: Accessed August 18, 2011.
  37. Vollmer WM, Markson LE, O’Connor E, Sanocki LL, Fitterman L, Berger M, Buist AS. Association of asthma control with health care utilization and quality of life. Am J Respir Crit Care Med. 1999;160(5 pt 1):1647-1652.
  38. Vollmer WM, Markson LE, O’Connor E, Frazier EA, Berger M, Buist AS. Association of asthma control with health care utilization: a prospective evaluation. Am J Respir Crit Care Med. 2002;165(2):195-199.
  39. Skinner EA, Diette GB, Algatt-Bergstrom PJ, Nguyen TT, Clark RD, Markson LE, Wu AW. The Asthma Therapy Assessment Questionnaire (ATAQ) for children and adolescents. Dis Manag. 2004;7(4):305-313.
  40. Thoonen BPA, Schermer TRJ, van den Boom G, Molema J, Folgering H, Akkermans RP, Grol R, Van Weel C, Van Schayck CP. Self-management of asthma in general practice, asthma control and quality of life: a randomised controlled trial. Thorax. 2003;58(1):30-36.
  41. Janson SL, Fahy JV, Covington JK, Paul SM, Gold WM, Boushey HA. Effects of individual self-management education on clinical, biological, and adherence outcomes in asthma. Am J Med. 2003;115(8):620-626.
  42. Yawn B, Mannino D, Littlejohn T, Ruoff G, Emmett A, Raphiou I, Crater G. Prevalence of COPD among symptomatic patients in a primary care setting. Curr Med Res Opin. 2009;25(11):2671-2677.
  43. Miller DP, Mannino DM, Althoff B. Factors associated with a higher CCQ score in patients with COPD from the US COPD REVEALED survey. Am J Respir Crit Care Med. 2010;181:A5932.
  44. Stenton C. The MRC breathlessness scale. Occup Med. 2008;58(3):226-227.
  45. American Thoracic Society. Quality of Life Resource. St. George’s Respiratory Questionnaire. Accessed February 21, 2011.
  46. Jones PW, Quirk FH, Baveystock CM, Littlejohns P. A self-complete measure of health status for chronic airflow limitation. Am Rev Respir Dis. 1992;145(6):1321-1327.
  47. Anzueto A, Leimer I, Kesten S. Impact of frequency of COPD exacerbations on pulmonary function, health status and clinical outcomes. Int J Chron Obstruct Pulmon Dis. 2009;4:245-251.
  48. Brusse-Keizer MG, van der Palen J, van der Valk PD, Hendrix R, Kerstjens HA. Clinical predictors of exacerbation frequency in chronic obstructive pulmonary disease. Clin Respir J. 2010, Nov 25. doi: 10.1111/j.1752-699X.2010.00234.x.
  49. Osman LM, Godden DJ, Friend JAR, Legge JS, Douglas JG. Quality of life and hospital re-admission in patients with chronic obstructive pulmonary disease. Thorax. 1997;52(1):67-71.
  50. American Thoracic Society. Quality of Life Resource. Instruments. Criteria for Inclusion. Available at: Accessed June 19, 2011.