Alternative ways of expressing forced expiratory volume in the first second and long-term mortality in elderly patients with asthma

Forced Expiratory Volume in One Second Quotient (FEV1Q) as a Prognostic Factor in Amyotrophic Lateral Sclerosis Patients: Comparing Its Predictive Value to Other Lung Function Measurements

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder affecting the first and second motor neurons. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) have conventionally served as indicators of respiratory muscle strength. Recently, FEV1Q (FEV1 divided by the sex-specific first percentile values of absolute FEV1 in adults with lung disease) has been suggested as a predictor of mortality. While FVC has been utilized as a prognostic factor, FEV1Q has not yet been examined.

METHODS

This retrospective unicenter study evaluated FEV1Q as a predictor of mortality in ALS patients, comparing its predictive efficacy with other measurements, including FEV1, FVC, sniff nasal inspiratory pressure, and maximal inspiratory pressure. The study utilized univariate analysis for each variable employing the Cox proportional hazards model to determine the statistical significance and predictive power of each measurement.

RESULTS

Forty-five patients were included, female predominant (60%) and an average age at diagnosis of 69.2 ± 11 years. Almost all (95%) met the criteria for non-invasive ventilation (NIV) and initiated (93%) during the study period, a mean of 137 days after diagnosis. The mortality rate observed was 57%, occurring at a median of 398 days post-diagnosis. On average, patients underwent 1.7 pulmonary function tests, revealing a decline in various parameters, including FEV1, FEV1Q, and FVC. However, only FEV1Q was a statistically significant predictor of mortality (p < 0.0083) in a Cox regression analysis. A negative coefficient for FEV1Q indicated that higher values were associated with a reduced mortality risk, with an average FEV1Q of 2.68 observed at the time of death.

CONCLUSION

FEV1Q emerged as the only statistically significant predictor of mortality among the evaluated respiratory measurements in ALS patients. This study is the first to focus on applying FEV1Q in the clinical evaluation of ALS, marking an initial step in understanding its potential role in patient follow-up. However, further studies are needed before these findings can be incorporated into clinical practice.

GOLD Staging System is Appropriate to Predict Mortality in Older People With Chronic Obstructive Pulmonary Disease

INTRODUCTION

In the new GOLD classification the reduction of FEV1, expressed as percentage of predicted value (FEV1PP), is considered an important prognostic factor. However, the use of FEV1PP may introduce bias, especially if based on equations derived from populations different from the one under study. We evaluated how well the GOLD classification stratifies the mortality risk when FEV1PP is based on an equation developed in the same population that gave rise to cases, externally developed equations, or as FEV1 divided by cubed height (FEV1/Ht3).

METHODS

We studied 882 participants aged ≥65 years. Bronchial obstruction was defined using a fixed cut-off of 0.7 for FEV1/FVC. Predicted values of FEV1 were derived from equations based on the same sample of the cases included in this study and from the European Respiratory Society equations. Severity of bronchial obstruction was also classified according to quartiles of FEV1/Ht3.

RESULTS

All the classification systems showed a non-statistically significant linear tendency with 5-years mortality risk. For the 15-years mortality, the linear trend across severity stages is more evident for GOLD classifications, with significant increments in the hazard ratio. Stratification by FEV1/Ht3 could better discriminate the functional status of participants.

CONCLUSION

The severity of bronchial obstruction according to GOLD classes may stratify mortality risk better than quartiles of FEV1/Ht3, whereas the second seems to be more suited to stratify the risk of clinical outcomes. Concerns about the use of externally developed reference values to calculate FEV1PP do not seem confirmed, at least for GOLD classification.

Short-term prognostic value of forced expiratory volume in 1 second divided by height cubed in a prospective cohort of people 80 years and older

Background

Spirometry-based parameters of pulmonary function such as forced expiratory volume in 1 second (FEV₁) have prognostic value beyond respiratory morbidity and mortality. FEV₁ divided by height cubed (FEV₁/Ht³) has been found to be better at predicting all-cause mortality than the usual standardization as percentage of predicted "normal values" (FEV₁%) and its use is independent of reference equations. Yet, limited data are available on the very old adults (80 years and older) and in association to other adverse health outcomes relevant for this age group. This study aims to investigate the short-term prognostic value of FEV₁/Ht³ for all-cause mortality, hospitalization, physical and mental decline in a cohort of very old adults.

Methods

In a population-based prospective cohort study of 501 very old adults in Belgium, comprehensive geriatric assessment and spirometry were performed at baseline and after 1.7 ± 0.21 years. Kaplan-Meier curves for 3-year all-cause mortality and hospitalization rates and multivariable analysis adjusted for age, sex, smoking status, co-morbidities, anemia, high C reactive protein and creatinine levels examined the association of FEV₁/Ht³ with all-cause mortality, unplanned hospitalization and decline in mental and physical functioning. Physical functioning was assessed by activities of daily living, a battery of physical performance tests and grip strength. Mental functioning was assessed with mini mental state examination and 15 items geriatric depression scale.

Results

Individuals in the lowest quartile of FEV₁/Ht³ had a statistically significant increased adjusted risk for all-cause mortality (hazard ratio [HR] 1.69, 95% confidence interval [CI] 1.10-2.60) and unplanned hospitalization (HR 1.65, 95% CI 1.21-2.25), as well as decline in physical (odds ratio [OR] 1.89, 95% CI 1.05-3.39) and mental functioning (OR 2.39, 95% CI 1.30-4.40) compared to the rest of the study population.

Conclusions

In a cohort of very old adults, low FEV₁ expressed as FEV₁/Ht³ was found to be a short-term predictor of all-cause mortality, hospitalization and decline in physical and mental functioning independently of age, smoking status, chronic lung disease and other co-morbidities. Further research is needed on FEV₁/Ht³ as a potential risk marker for frailty and adverse health outcomes in this age group.