9.8.5 Chapter 1 – Cardiorespiratory Impairment

Cardiorespiratory impairment generally results from conditions or diseasses that affect the function of a person's heart or lungs.

Conditions to be assessed under Chapter 1

GARP explains what conditions should be assessed under Chapter 1 of the Guide and how the assessment of a client’s condition should be performed to calculate the impairment rating.  In assessing the impairment clinical features of injuries or diseases are to be taken into account and in all cases should be determined by following each of the steps described in the Chapter. Assessors should be aware of the ‘Introduction’ and ‘How To Use This Guide’ sections of GARP and follow these in conjunction with the relevant medical sections of the chapter when assessing and determining the relevant impairment rating.

Exercise tolerance and measurement of lung function

Generally, cardiorespiratory impairment is measured by reference to exercise tolerance.

Spirometry should always be obtained if any condition affecting the function of the lungs is present. The spirometry tests will obtain the usual physiological measurements of lung function which are FEVl, FVC, and MEF 25-75. Chapter 1 sets out the steps for obtaining the readings from spirometry tests and how to find the corresponding impairment rating.

MEF25-75 Measurements

For the purpose of determining a rating under Table 1.1, GARP instructs that first all relevant data/measurements (including MEF25-75) are collected and expressed as a percentage of the predicted measurement.

The Guide states that the person assessing the data should determine the 'appropriateness' of the MEF data in the particular circumstances, and whether it is included in following steps to calculate the impairment rating.  The person undertaking the GARP assessment and determining the level of impairment therefore has scope for the consideration of the inclusion or exclusion of the MEF 25-75 data as a marker of impairment, and this discretion should be exercised on a case-by-case basis, rather than a one-size-fits-all approach

There is no explicit ruling made on the use of the measurement, however the Guide states for the measurements of lung function that readings of spirometry should be consistent with the conditions affecting the veterans and there should be no unexplained inconsistencies between various reports/readings.  The collection and inclusion of the recorded MEF data, if obtained by an assessing doctor should generally be used as part of the GARP assessment where it is consistent with the client's condition and impairment. When the "nature of the Spirometry cannot be reconciled with other relevant information" repeat Spirometry tests should be conducted or Specialist review to reconcile any differences.

There are cases where a discrepancy will exist between the clinical-scientific understanding of a condition or other evidence of the functional impairment and the impairment rating obtained (when including MEF data). Examples below have been provided as a guide that illustrate such cases and where MEF data may or may not be relevant to assessing an impairment rating under GARP.

• Asthma assessments it would more often than not, be appropriate to include the MEF25-75.

There is a strong relationship to other markers of disease severity and FEV1 and FVC are often normal, MEF25-75 can accurately represent the impact of the disease.

• COPD and emphysema where other spirometry readings are normal there is reasonable medical argument to include MEF25-75.

MEF25-75 may well have been used as the diagnostic test and should be used for the impairment assessment. If there is a marked discrepancy between the MEF25-75 rating and a MET rating in the presence of cardiac disease, it would be reasonable to obtain further information in order to reconcile the differences.

• COPD and emphysema where other spirometry readings are reduced there is reasonable medical argument to not include MEF25-75.

In this case, the MEF25-75 may not be a reliable investigation findings (as it is not reproducible), not an accurate marker of the severity of the disease, and not likely to reflect the functional impact.

Note: these are examples only, and should not limit an assessor’s consideration of other or different conditions for which MEF data may or may not be an accurate marker of the disease and included in the assessment.  

If there is medical opinion provided that use of MEF data is not appropriate at Step 4, reasons for this are to be provided by a CMA for excluding the measurement from the GARP assessment rather than disregarding MEF data in all cases.  A CMA opinion ultimately is not an independent decision from the GARP assessment, therefore it is up to the Delegate to determine the final impairment and if the CMA’s opinion is accepted and incorporated into the final assessment. Part of the Delegate’s decision making is to weigh up all of the available medical evidence including input from a CMA when determining impairment.  Delegates should ensure they understand the medical opinion being provided by a CMA and be reasonably satisfied with any justification provided in support of including or excluding MEF 25-75 data.