Conformity of spirometric tests with acceptability criteria and assessment of confounding factors in routine clinical practice.

Background: Spirometry is one of the basic methods used in the diagnosis, treatment, and follow-up of respiratory disease. Spirometric test results that do not comply with international standards may be misinterpreted and lead to misdiagnosis and treatment. We aimed to assess the tests of patients that meet the "American Thoracic Society/European Respiratory Society (ATS/ERS) 2019" recommendations, to identify the most common errors, and to explore patient characteristics possibly associated with failure to reach these standards.

Methods: A total of 1000 spirometries performed between January and December 2023 were randomly selected retrospectively. Spirometric maneuvers were evaluated for meeting the acceptability criteria of the ATS/ERS 2019 guidelines.

Results: The acceptability spirometry rate was 62.5%. The most frequently unmet criterion was failure to meet any of the three ends of forced expiration at 20.7%. There was no significant difference between male and female in terms of the acceptability of maneuvers. The 45-59 and 60-74 age groups were statistically more significant than the younger and older. Smoking, diagnosis of chronic obstructive pulmonary disease, and number of spirometry practices were significantly associated with conformity to test acceptability criteria. The forced expiratory volume in 1 second (FEV1) divided by the forced vital capacity, FEV1, and forced expiratory times had a statistically significant independent effect on the acceptability of spirometric maneuvers.

Conclusion: Nearly one-third of the tests performed by an experienced technician in a tertiary care hospital did not meet the acceptability criteria. Our study shows the importance of the learnability of maneuvers through repeated spirometry experiences.