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The CARE-COAD #1 Study

(The first Chronic Obstructive Airways Disease study)
- a multinational e-mail/web-based study
Copyright ©1998-2002, CARE-COAD #1
* Completed December 1998 *

Notes Study Questions Definition of Disease Sampling of Investigators Sampling of Study Patients Clinical Examination Spirometers and Spirometry Data Recording and Submission Analyses & Reporting of Results

Notes:

This study was completed in November, 1998 and the results of the analysis will be available for all participating investigators to review by the end of January, 1999.
  1. For ease in abbreviation, we shall use the term COAD to denote all of the following terms: Chronic Obstructive Lung Disease/ Chronic Airflow Limitation/ Chronic Airflow Obstruction/ Chronic Obstructive Airways Disease/. It includes patients with underlying asthma and/or partial/complete reversibility with bronchodilators. We are taught to diagnose COAD from a wide array of patient characteristics (our text and journal search unearthed 45 of them!), including our global clinical impressions. We need to bear in mind that in this first "go" we are picking off just a few of them to see how they relate to simultaneous spirometry. Our results will provide the start, not the end, of our attempt to whittle those 45 items down to just the accurate and precise ones. Based on our discussions around these results, we will decide together whether and how to proceed to the next study in the COAD series.
  2. Our definition of COAD is an FEV1 < 5th percentile, and/or FEV1/FVC < 5th percentile (but we also will analyse the results for an FEV1/FVC <70%)
  3. The terms "spirometry" and "spirometrist" will be used to denote any measure of lung function, carried out by anyone with at least rudimentary training in the use of a simple (hand-held) or fancy (pulmonary function lab) device for measuring lung function. It is vital that the spirometrist is blind to the clinical examination (and vice-versa).
  4. Each participant should take responsibility for finding out and adhering to what their local policy is for the ethics approval of this study. Where we work, formal ethics approval is not necessary, but this varies by site. In the rare (we hope!) case in which ethics approval is required only for examining normal patients, participants are encouraged to enter "known" and "suspected" patients while awaiting approval for the "normal" group. (To save yourselves some time, you might want to see about getting blanket approval for future studies)
  5. We would like to have as many patients entered as possible by Nov 15 and participating investigators must have their data collected and entered on the website by 30th November 1998.

 

Study Questions:

  1. Among consecutive patients known* by their examiners to have COAD, what is the accuracy (singly or in combination, and validated against "blind" spirometry) of the following items?
    • Low larynx (by distance from the top of the thyroid cartilage to the suprasternal notch, measured in finger breadths and translated to the nearest lowest centimetre)
    • Laryngeal descent on inspiration (as above)
    • Smoking history (ever smoked cigarettes for more than one year and pack-years smoking history)
    • Age (last birthday)
    • Sex
    • Wheeze (auscultation at four points on the posterior chest)

    * known: known to have an FEV <5th percentile and/or an FEV1/FVC <5th percentile or <0.7; or patient states they've been told they have COAD; or patient is taking inhaled bronchodilators and/or inhaled steriods.

  2. Among consecutive patients not known, but suspected* by their examiners (or by their referring clinicians) to have COAD, what is the accuracy of these items?

    * suspected: satisfies none of the criteria for "known" COAD, but either is referred to you by a clinician for suspected COAD or you, at the conclusion of the history, think that it is clinically sensible to suspect COAD.

  3. Among patients who are neither known nor suspected by their examiners to have COAD, what is the accuracy of these items?

 

Definition of Disease:

  1. We have asked our respirology colleagues to refer us to any "official" definitions.
  2. Our literature search revealed a 1996 review of articles published in Chest and Thorax from July 1991-July 1993 whose titles or summaries referred to "asthma," "chronic obstructive lung disease," or "chronic airflow obstruction." They found 11 different criteria, the most common of which was an FEV1/FVC < 0.7 (Quadrelli SA et al: Respiration 1996;63:131-6.) However, The American Thoracic Society suggests that this is not an appropriate reference standard to use and suggests using an FEV1/FVC < 5th percentile or an FEV1 < 5th percentile (Am Rev Respir Dis 1991;144:1202-18). We will try various definitions based on FEV1/FVC and FEV1 (again, regardless of whether the target disorder is asthma and/or is partially-reversible with bronchodilators).

 

Sampling of Investigators:

  1. Investigators will join the study as "teams" of 2 or more (either 2 clinicians or 1 clinician and one "spirometrist") to enable the independent, blind comparison of the clinical findings with spirometry.
    • However, we will accept applications from solo clinicians as well if they can arrange (for the day(s) of the study) independent, blind spirometry.
  2. The clinical collaborators will be multinational.
  3. The clinical collaborators will include clinicians working in 3 different practice settings:
    • First contact clinicians seeing self-referred patients (primary care): examples include Commonwealth GPs, Family Practitioners, U.S.-style General Internists, some Accident & Emergency clinicians, and others who provide first-contact primary care
    • Second contact with patients referred by other clinicians. Examples include General Physicians, Geriatricians, and some Accident & Emergency Room clinicians who see patients referred to them by primary care clinicians.
    • Respirologists
      • .
  4. Investigators will enroll at least 12 study patients per participating clinician/team (4 patients known to have COAD; 4 suspected of COAD; 4 neither known nor suspected).
  5. Investigators use e-mail and internet for recruitment, data submission, presentation and discussion of study results, and generation of manuscripts.

 

Sampling of Study Patients:

  1. Will be of three sorts:
    • "Known": patients known to have an FEV1 <5th percentile and/or an FEV1/FVC <5th percentile (or < 0.7); or patient states they've been told they have COAD (chronic bronchitis / emphysema); or patient is taking inhaled bronchodilators and/or inhaled steroids.
    • "Suspected": patients who satisfy none of the criteria for "known" COAD, but either are referred to participating clinicians for suspected COAD, or participating clinicians, after taking a history, think that it is clinically sensible to suspect COAD.
    • "Normal": patients neither known nor suspected of COAD.

    Patients "known" or "suspected" of having COAD may have "asthma" as part of their presentation, and its status will be noted during the examination.

    Patients will be admitted consecutively (i.e. consecutive patients that the investigator sees in a time period specified by the investigator) within each category until the pledged sample size has been achieved.
  2. "Known" and "Suspected" patients can be enrolled during exacerbations of their asthma and/or COAD (as long as there is independent, blind spirometry within 30 minutes of the exam, and no bronchodilator treatment in between the exam and spirometry).
  3. Exclusions:
    • Patients who don't want to participate.
    • Patients with a terminal illness whose goals of therapy are confined to comfort and dignity.
    • Patients <18 years of age (no upper age limit).
    • Patients whose respiratory distress is too severe to withold bronchodilators until after spirometry.
    • Patients who are medically unstable from other causes (acute MI, on their way to ITU, etc)
    • Patients admitted for overdose.
    • Patients who are unable (due to cognition, level of consciousness, or language) to co-operate in either the exam or the spirometry.

 

Clinical Examination:

The physical exam manoeuvres should be performed in the following order:

  1. Laryngeal height
    • At end-inspiration with the patient sitting up, looking straight ahead and with hands relaxed in his/her lap, palpate the top of the thyroid cartilage which is readily identified by the notch on it superior edge.
    • Hook your index finger over the thyroid cartilage and using the rest of your fingers, measure the distance from the top of the thyroid cartilage to the sternal notch in finger-breadths.
    • Convert these finger-breadths to centimetres and record this distance.
  2. Laryngeal descent
    • Measure and record this same distance at its lowest point on inspiration
  3. Wheezes
    • Listen on deep respiration over 4 spots on the patient - bilateral upper and lower back
    • Any expiratory wheeze (continuous adventitious lung sound*) heard in any of these spots is considered positive for wheezing
    • Auscultation can be performed on bare skin or through the patient's clothing but this should be noted on the data collection form
* Sapira JD, The Art and Science of Bedside Diagnosis, Urban & Schwarzenberg: Munich, 1990.

 

Spirometers and Spirometry:

  1. Must provide FEV1 and FVC results (PEFR is optional, but insufficient by itself).
  2. Any hand-held spirometers will be checked by/discussed with a local Pulmonary Function Lab before the study.
  3. Spirometry will be carried out by standard protocol:
    • blind to the clinical examination results
    • done at least twice, with the higher result submitted,
    • done with standardised encouragement:
      • "Take a deep breath in - as full as you can"
      • "As soon as you have filled your lungs, put the end of the tube in your mouth and blow the air out as hard and fast as you can"
      • "Keep blowing until your lungs are completely empty"
      • "Keep blowing, keep blowing, etc..." (in a positive, encouraging tone of voice)
  4. Will be carried out within 30 minutes of the clinical examination, with no bronchodilators administered in between.

 

Data Recording and Submission:

This process will be streamlined and simple, with ticks for as many items as possible. The forms will be provided once you have registered.

Keep a copy of your completed data forms in case the journal to which we submit the publication would like random checks done on them.

Data Submission:

Data submission will be by online form.

In recording data, patient identity will be anonymous. Each investigator should have their own method of assigning patient ID numbers which should also be entered on the data collection sheets. To qualify for the study, each patient must have both a clinical exam data collection sheet and a spirometry data collection sheet.

 

Analyses:

Simple analyses will follow the approaches outlined in the JAMA "Primer" (JAMA 1992;267:2638-44). We also will do multivariate analyses looking for combinations of symptoms and signs. Early returns will serve as "training" sets and later returns as "test" sets for more complex combinations of findings.

Reporting the Results and Rules for Credit, Co-Authorship, and Acknowledgement:

  1. First analyses and draft reports will be sent only to participating investigators.
  2. After the investigators are satisfied with the (modified) analyses and reports, powerpoint slides will be sent (electronically) to each investigator (for local presentation), and the study will be summarised on the Internet (in a fashion that will not jeopardise its publication in a journal).
  3. Abstracts will be proposed and submitted to national and international meetings by mutual agreement, with authorship that includes the phrase "on behalf of the CARE-COAD Study #1 Group."
  4. Manuscripts will be submitted by mutual agreement, again with authorship that includes the phrase "on behalf of the CARE-COAD Study #1 Group."
  5. Publications will include a list of all participants, in descending order, who submitted usable data on 12 or more patients and all methodologists involved with the study.