A Scoring System To Aid In The Interpretation Of Cardiopulmonary Test Results

Cardiopulmonary analysis during graded exercise testing (CPX) is commonly used to diagnose illness and determine physical working capacity. Given the number of variables generated during CPX it can be difficult to provide concise and meaningful interpretations for health personnel not familiar with its use. We proposed to develop a scoring system yielding a composite score that describes physiological function and working capacity using the results from a two day test-retest CPX. The purpose is to provide a single score that accurately describes performance in order to compare one day‘s performance with the next. METHODS: CPX results from a group of women with chronic fatigue syndrome (n=15) and age-, gender- and weight-matched sedentary controls (n=15) were employed to develop the scoring system. Peak values for oxygen consumption, heart rate and ventilation were compared with age- and gender-predicted values. If an individual achieved at least 85% of predicted values this corresponded to value of 5 points. One point was subtracted for each 10% decrement below the 85% predicted value, and 1 point was added for each 10% increment above 100% of predicted. Scoring for anaerobic threshold (AT) was given a full 5 point value for achieving 40% of predicted peak oxygen consumption and one point deducted for 10% increments below 40% and above 60% of predicted peak oxygen consumption. Reaching 85% of predicted values for every variable resulted in a composite score of 25 points. RESULTS: To be included, each subject reached ACSM criteria for maximal effort on both test days the control subjects achieved an average score of 27.9±4.0 on test 1 and 29.1±5.6 on test 2. The CFS subjects scored 26.0±5.3 on test 1 and 24.7±5.3 on test 2. For the control subjects eleven out of 15 achieved at least 85% of their predicted max and scores of 25 or above for test one. For test two, ten out of 15 achieved values of 25 or above. In the CFS group 10 out of 15 achieved 25 points on test one and 7 out of 15 for test 2. CONCLUSIONS: The scoring system as employed can be used to describe performance compared with age- and gender-predicted values and may be helpful in describing the reduction in physical performance in a test-retest situation. This scoring system better describes the differences in physical capabilities than a previously employed method.