Researchers have found that genetic ancestry significantly affects the performance on the lung function tests. These tests are done to detect signs of illness like asthma and chronic obstructive pulmonary disease. It is based on these tests; doctors make decisions about disability claims and eligibility for lung transplants.

Rajesh Kumar, MD, of Northwestern University and Children's Memorial Hospital in Chicago believes that more effective and efficient care can be taken if there is an improvement in the accuracy of predicted lung function. He also stated that taking a patients’ genetic ancestry into account could result in more accurate prediction of lung function.

Dr. Paul D. Scanlon also considers these findings as a step forward in understanding these diseases.

Presently tests are a very crude tool as they depend on self identified race. Adjustments are based on factors such as age, sex, race and weight. Recent studies have found that adjustments based on genetic ancestry are more accurate in people having mixed ancestry. Dr. Esteban G. Burchard suggests that people throughout the world have a richer genetic heritage and it is very difficult to capture by present definitions of race. He also thinks that doctors would be missing important genetic information by classifying patients into individual boxes, such as ‘African-American’ or ‘Caucasian’.

Kumar and co-authors analyzed several self-identified African-American participants to assess the effect of ancestry versus self identified race on lung functions. They were analyzed in the Coronary Artery Risk Development in Young Adults (CARDIA) study. They conducted 5 studies in which one of most common of the Pulmonary Function Tests (PFTs), spirometry was performed according to American Thoracic Society guidelines.

The results found were astonishing as the severity of asthma would be misclassified for approximately 4% of the patients (roughly around 80,000).The authors concluded saying that the misclassification is bound to affect even more patients with COPD, a condition more common than asthma.