Time Of Day, Year Matters For Asthma Testing

MONDAY, March 17, 2025 (HealthDay News) -- The time of day -- or year -- an asthma test takes place can affect its accuracy, a new study says.

Routine asthma testing is more reliable when done in the morning, researchers reported in the journal Thorax.

Starting at 8:30 a.m., the chances of the test accurately detecting a person’s asthma decreases by 8% for every subsequent hour that passes, results show.

People are also 33% less likely to have a positive result on an asthma test if it is done during the autumn compared to the winter, researchers found.