Age and mini-mental state examination score can predict poor-quality spirometry in the elderly: a cross-sectional study

OBJECTIVES: The goal was to identify predictors of poor-quality spirometry in community-dwelling older adults and their respective cutoffs. METHODS: This was a cross-sectional population-based study involving 245 elderly subjects (age≥60 years). The spirometric data were categorized as good or poor quality, and cognitive status was assessed using an adapted version (scaled to have a maximum of 19 points) of the Mini-Mental State Examination. Multivariate analysis was used to assess the association between poor-quality spirometry and sociodemographic, behavioral and health characteristics. The best cutoff points for predicting poor-quality spirometry were evaluated by the receiver operating characteristic curve. RESULTS: In this population, 61 (24.9%) subjects with poor-quality spirometry were identified. After multiple logistic regression analysis, only age and Mini-Mental State Examination score were still associated with poor-quality spirometry (p≤0.05). The cutoff for the Mini-Mental State Examination score was 15 points, with an area under the receiver operating characteristic curve of 0.628 (p=0.0017), sensitivity of 74.5% and specificity of 49.5%; for age, the cutoff was 78 years, with an area under the receiver operating characteristic curve of 0.718 (p=0.0001), sensitivity of 57.4% and specificity of 79.9%. CONCLUSION: Age and Mini-Mental State Examination score together are good predictors of poor-quality spirometry and can contribute to the screening of community-dwelling older adults unable to meet the minimum quality criteria for a spirometric test.