There are other types of pulmonary function tests that patients can perform themselves at home. Home testing may be recommended for people who need to monitor their condition between office visits. These tests are particularly useful for asthma patients, who can chart their test results and monitor them for signs of an impending asthma attack.

Home tests can measure the following aspects of lung function:

• Force of exhalation. Sometimes called a match test, patients attempt to blow out a match held approximately 6 inches away from the face. Results are normal if completed without any trouble.
  
  
• Forced expiratory time (FET). Patients time how quickly they can exhale a deep breath of air through the mouth. Results are normal if all air can be expelled within five seconds.
  
  
• Forced vital capacity (FVC) and forced expiratory volume (FEV). Patients quickly and forcefully blow into a hand-held spirometer and record the resulting measurements. The hand-held spirometer comes with tables that include predicted values to determine whether the patient’s measured values are normal. To calculate the measured values, patients divide the recorded numbers by the numbers that would be expected for someone of their height, weight, age and gender (the predicted values). This home test is normal if the calculated fractions are at least .80 (80 percent).
  
  
• Maximum ventilation volume (MVV). Patients repeatedly inhale and exhale as quickly as possible into a hand-held spirometer for 15 seconds, and record the value (recorded value). Multiplied by four, this value represents "VV" for a full 60 seconds. The hand-held spirometer comes with tables that include predicted values to determine whether the measured value is normal. To calculate the measured value, patients divide the recorded value by the number that would be expected for someone of his or her height, weight, age and gender (the predicted value). This home test is normal if the calculated fractions are at least .80 (80 percent).
  
  
• Peak expiratory flow rate (PEFR). Patients quickly and forcefully blow into a peak expiratory flow monitor and record the resulting measurement. The measurement can be compared to a “personal best” score, which is the highest peak–flow measurement recorded over a two–week period when a condition is under control. A score that is between 80 percent and 100 percent of a patient’s personal best score means the test is normal.
  
  Though it is best to establish a personal best score, peak expiratory flow can also be measured against predicted “normal” peak flow levels. Peak expiratory flow monitors come with tables that include predicted values to determine if the measured value is normal. To calculate the measured value, patients divide the recorded value by the number that would be expected for someone of his or her height, weight, age and gender (the predicted value). This home test is normal if the calculated fractions are at least .80 (80 percent).
  
  

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If abnormal results are obtained for the first time through home testing, or if results suddenly worsen, patients are encouraged to contact their physician.

It is also important to note that these tests are only valid if the effort is consistent between uses, and as long as the technique is good and reproducible.