Medical/Professional Relations

Guide To Pulmonary Function Studies Under Social Security Programs

The Social Security Administration (SSA) administers two disability programs, Social Security Disability Insurance (SSDI) and the Supplemental Security Income (SSI) program. SSDI is a social insurance program financed through Social Security payroll taxes paid by workers and their employers. Eligibility for these disability benefits is based on an individual's work history, and the amount of the benefit is based on the individual's earnings. SSI payments, financed through general revenues of the U.S. Treasury, are paid only to those aged, blind, or disabled individuals with limited income and resources.

The medical definition of disability is the same for both programs; i.e., an individual must be unable "to engage in any substantial gainful activity (work) by reason of any medically-determinable physical or mental impairment which can be expected to result in death or which has lasted or can be expected to last for a continuous period of not less than 12 months." Children applying for SSI benefits must have an impairment that results in marked and severe functional limitations.

Applications for disability benefits are taken in SSA's 1300 field offices. At the point of application, information is gathered on the claimant's impairments, functional restrictions, treating sources, and vocational history. However, the actual development of the claim and the disability determination are made by an agency in each State called the Disability Determination Services (DDS). Although administered by the States, the DDSs are fully funded by the Federal Government and are required to comply with federally-prescribed policies and procedures. The DDSs use a team approach (consisting of a physician and a disability examiner) to make disability decisions.

The DDS begins the disability determination process by requesting medical evidence of record--specifically, information about the claimant's impairment(s)--from the treating sources (those physicians, psychologists, hospitals, clinics, etc., identified by the claimant on his or her application). This evidence is extremely important in the disability process because it provides a longitudinal picture of the claimant's impairment(s).

However, if that evidence is insufficient to render a determination, the DDS will purchase a consultative examination from the treating source or, if the treating source is unable or unwilling to conduct the examination, from an independent source. The DDS relies on respiratory therapists and technicians to perform pulmonary function studies (PFS) needed to evaluate claims involving respiratory impairments.

Role of the Respiratory Therapist/Technician in Disability Evaluation

Although respiratory therapists/technicians take no part in the actual disability determination (those decisions are made by teams of physicians, disability examiners, and often vocational consultants within the DDS), their role in disability evaluation under Social Security is twofold: 1) to ensure that the tests are performed and reported accurately, and 2) to "coach" the disability applicant to ensure he or she understands and follows directions to the best of his or her capability.

PFS should be administered according to SSA's guidelines with the applicant's full cooperation. The test results should be reported and the tracings submitted to enable the physician in the DDS to independently assess the test values for the forced expiratory volume (FEV1 ) and forced vital capacity (FVC) reported by the respiratory therapist/technician who performed the test.

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Proper Documentation: A Need Nationwide

Proper documentation of pulmonary impairments for Social Security disability evaluation purposes is critical. This is particularly true because of the varied types of spirometric equipment and various differences in reporting techniques employed in clinics and hospitals.

In order to ensure that spirometry is performed consistently, particularly for tests that SSA purchases, SSA has published specific guidelines for the performance of spirometry. This pamphlet contains these basic requirements, but a more thorough explanation of the criteria is included in sections 3.00 (Part A for adults) and 103.00 (Part B for children) of the handbook entitled, Disability Evaluation Under Social Security (SSA Publication 64-039). A copy of this handbook may be obtained by contacting the DDS professional relations staff in your State.

The following guidelines have been established to promote consistency in the performance and reporting of spirometry results. When performing spirometry purchased by SSA, we require you to adhere to these guidelines.

Performance of Spirometry

. The one-second FEV1 and FVC values that are used for evaluation of
  disability claims should be expressed in liters (L), body temperature and
  pressure saturated with water vapor (BTPS).

. The reported FEV1 and FVC should represent the largest of at least 3
  satisfactory forced expiratory maneuvers.

. Two of the satisfactory spirograms should be reproducible for both
   pre-bronchodilator tests and, if indicated, post-bronchodilator tests.
   A value is considered reproducible if it does not differ from the largest
   value by more than 5% or 0.1 L, whichever is greater.

. The highest values of the FEV1 and FVC, whether from the same or
  different tracings, will be used to assess the severity of the respiratory
   impairment.

. Peak flow should be achieved early in expiration, and the spirogram
  should have a smooth contour with gradually decreasing flow throughout
  expiration.

. The zero time for measurement of the FEV1 and FVC, if not distinct,
  should be derived by linear back-extrapolation of peak flow to zero volume.
  A spirogram is satisfactory for measurement of the FEV1 if the expiratory
  volume at the back-extrapolated zero time is less than 5% of the FVC or
  0.1 L, whichever is greater.

. The spirogram is satisfactory for measurement of the FVC if maximal
  expiratory effort continues for at least 6 seconds, or if there is a plateau in
  the volume-time curve with no detectable change in expired volume during
  the last 2 seconds of maximal expiratory effort.

. Spirometry should be repeated after administration of an aerosolized
  bronchodilator under supervision of the testing personnel if the
  pre-bronchodilator FEV1 value is less than 70% of the predicted normal
  value.

. PFS should not be performed unless the clinical status is stable (e.g., the
  individual is not having an asthmatic attack or suffering from an acute
  respiratory infection or other acute illness). Wheezing is common in
  asthma, chronic bronchitis, or chronic obstructive pulmonary disease and
  does not preclude testing. The effect of the administered bronchodilator in
  relieving bronchospasm and improving ventilatory function is assessed by
  spirometry. If a bronchodilator is not administered, the reason should be
  clearly stated in the report.

. PFS performed to assess airflow obstruction without testing after
  bronchodilators cannot be used to assess levels of impairment in the
  range that prevents any gainful work activity or in the case of a child
  (usually around age 6 or older) that results in marked and severe
  functional limitations, unless the use of bronchodilators is contraindicated.
  Post bronchodilator testing should be performed 10 minutes after
  bronchodilator administration. The dose and name of the bronchodilator
  administered should be specified.

. The appropriately labeled spirometric tracing, showing the claimant's
  name, date of testing, distance per second on the abscissa and distance
  per Liter on the ordinate, must be incorporated into the file. The
  manufacturer and model number of the device used to measure and
  record the spirogram should be stated.

. The testing device must accurately measure both time and volume, the
   latter to within 1% of a 3 L calibrating volume. If the spirogram was
   generated by any means other than direct pen-linkage to a mechanical
   displacement-type spirometer, the spirometric tracing must show a
   recorded calibration of volume units using a mechanical volume input
   such as a 3 L syringe.

. If the spirometer directly measures flow, and volume is derived by
  electronic integration, the linearity of the device must be documented by
  recording volume calibrations at 3 different flow rates of approximately
  30 L/min (3 L/6 sec), 60 L/min (3 L/3 sec), and 180 L/min (3 L/sec).
  The volume calibrations should agree to within 1% of a 3 L calibrating
  volume. If the accuracy is less than 99%, but within 3% of the calibrating
  syringe volume, appropriate corrections should be made to the recorded
  FVC and FEV1 values.

. The corrected FVC and FEV1 should be computed as follows:
  volume correction factor = actual syringe volume/measured volume.
  The measured FVC and FEV1 should be multiplied by the calibration
  correction factor. If the FVC and FEV1 tracings are at ATPS, the values
  should in turn be multiplied by the BTPS factor. When the measured
  FVC and FEV1 are at BTPS, the BTPS correction factor should not be
  applied again.

. The proximity of the flow sensor to the individual should be noted, and it
  should be stated whether or not a BTPS correction factor was used for
  the calibration recordings and for the individual's actual spirograms.

. The spirogram must be recorded at a speed of at least 20 mm/sec, and
   the recording device must provide a volume excursion of at least
  10 mm/L. If reproductions of the original spirometric tracings are
  submitted, they must be legible and have a time scale of at least
  20 mm/sec and a volume scale of at least 10 mm/L to permit independent
  measurements. Calculation of FEV1 from a flow-volume tracing is
  not acceptable; i.e., the spirogram and calibrations must be presented in
  a volume-time format at a speed of at least 20 mm/sec and a volume
  excursion of at least 10 mm/L to permit independent evaluation.

. A statement should be made in the pulmonary function test report of
  the individual's ability to understand directions, as well as his or her
  effort and cooperation, in performing the pulmonary function tests.

. The height of the individual--without shoes--must be recorded. If an
   individual has marked spinal deformities (e.g., kyphoscoliosis),
   the measured span between the fingertips with the upper extremities
   abducted 90 degrees should be substituted for height when this
   measurement is greater than the standing height without shoes.

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Spirometry Checklist

The following checklist for the criteria listed above, is intended as a quick reference when performing PFS.

The test should not be performed during or soon after acute respiratory illness or if medically contraindicated.

1. Expired volumes must be expressed in liters BTPS.

2. There must be at least 3 satisfactory forced expiratory maneuvers
    pre-bronchodilator.

3. Two of the satisfactory expiratory maneuvers should be reproducible;
     i.e., do not differ from the largest value by more than 5% or 0.1 L,
     whichever is greater.

4. Peak flow must be achieved early in expiration.

5. Spirogram must have smooth contour with gradually decreasing flow
    throughout expiration.

6. Zero time measurement of the FVC and FEV1, if not distinct, should be
    derived from linear back-extrapolation of peak flow to zero volume.
    Spirogram is satisfactory for measurement of FEV1 if the expiratory
     volume at the back-extrapolated zero time is less than 5% of the FVC
     or 0.1 L, whichever is greater.

7. Spirogram is satisfactory for measurement of the FVC if maximal
    expiratory effort continues for at least 6 seconds, or if there is a plateau
    in the volume-time curve with no detectable change in the expired
    volume during the last 2 seconds of maximal expiratory effort.

Calibration

1. Spirometric tracing must show a recorded calibration of volume units
    using a mechanical volume input, such as a 3 L syringe, unless the
    tracing is generated by direct pen-linkage to a mechanical
    displacement-type spirometer.

2. If the spirometer directly measures flow, and volume is derived by
    electronic integration, the linearity of the device must be documented by
    recording volume calibrations at 3 different flow rates:
    (3 L/6 sec)  (3 L/3 sec) (3 L/sec).

3.  Volume calibrations should agree to within 1% of a 3 L calibrating
     syringe volume. If accuracy is less than 1% but within 3% of the
     calibrating syringe, use the following formula: volume correction
     factor = actual syringe volume/measured volume.

    The measured FVC and FEV1 should be multiplied by the calibration
    correction factor. If the FVC and FEV1 tracings are at ATPS, the values
    should in turn be multiplied by the BTPS factor. When the measured
    FVC and FEV1 are at BTPS, the BTPS correction factor should not
    be applied.

4. Proximity of the flow sensor to the individual should be noted.

It should be noted whether a BTPS correction factor was used for the calibration recordings and for the actual test.

Tracings

1. Provide tracings of all 3 FVC attempts, pre and post-bronchodilator.

2. Must be appropriately labeled, showing claimant's name, date of testing,
    distance per second on the abscissa, and distance per liter on the
    ordinate.

3. Must have a time scale of at least 20 mm/sec.

4. Must have a volume scale of at least 10 mm/L.

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NOTE: CALCULATION OF FEV1 FROM A FLOW-VOLUME TRACING IS
            NOT ACCEPTABLE.

Post-bronchodilator

1. Post-bronchodilator studies should be done if the pre-bronchodilator
    FEV1 is less than 70% of the predicted normal value (unless
    contraindicated).

2. Include dose and name of bronchodilator administered in the report.

3. Post-bronchodilator testing should be done 10 minutes after
    administration of the bronchodilator.

Other Reporting Information

1. Manufacturer and model number of device used to measure and record
    the spirogram should be stated.

2. Statement regarding individual's ability to understand directions, as well
    as effort and cooperation, should be included.

3.  If a bronchodilator is not administered, please indicate the reason why.

4.  Height of the individual--without shoes--must be recorded.  If you have
     any questions regarding information presented in this pamphlet or the
     medical criteria used to evaluate disability under Social Security, please
     contact the Professional/Medical Relations Officer in your State.

A complete list of Medical/Professional Relations Officers in your State is also available.

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