methods Archives - Critical Care Science (CCS)
Abstract
Crit Care Sci. 2024;36:e20240246en
DOI 10.62675/2965-2774.20240246-en
To discuss the strengths and limitations of ventilator-free days and to provide a comprehensive discussion of the different analytic methods for analyzing and interpreting this outcome.
Using simulations, the power of different analytical methods was assessed, namely: quantile (median) regression, cumulative logistic regression, generalized pairwise comparison, conditional approach and truncated approach. Overall, 3,000 simulations of a two-arm trial with n = 300 per arm were computed using a two-sided alternative hypothesis and a type I error rate of α = 0.05.
When considering power, median regression did not perform well in studies where the treatment effect was mainly driven by mortality. Median regression performed better in situations with a weak effect on mortality but a strong effect on duration, duration only, and moderate mortality and duration. Cumulative logistic regression was found to produce similar power to the Wilcoxon rank-sum test across all scenarios, being the best strategy for the scenarios of moderate mortality and duration, weak mortality and strong duration, and duration only.
In this study, we describe the relative power of new methods for analyzing ventilator-free days in critical care research. Our data provide validation and guidance for the use of the cumulative logistic model, median regression, generalized pairwise comparisons, and the conditional and truncated approach in specific scenarios.
Abstract
Crit Care Sci. 2024;36:e20240246en
DOI 10.62675/2965-2774.20240246-en
To discuss the strengths and limitations of ventilator-free days and to provide a comprehensive discussion of the different analytic methods for analyzing and interpreting this outcome.
Using simulations, the power of different analytical methods was assessed, namely: quantile (median) regression, cumulative logistic regression, generalized pairwise comparison, conditional approach and truncated approach. Overall, 3,000 simulations of a two-arm trial with n = 300 per arm were computed using a two-sided alternative hypothesis and a type I error rate of α = 0.05.
When considering power, median regression did not perform well in studies where the treatment effect was mainly driven by mortality. Median regression performed better in situations with a weak effect on mortality but a strong effect on duration, duration only, and moderate mortality and duration. Cumulative logistic regression was found to produce similar power to the Wilcoxon rank-sum test across all scenarios, being the best strategy for the scenarios of moderate mortality and duration, weak mortality and strong duration, and duration only.
In this study, we describe the relative power of new methods for analyzing ventilator-free days in critical care research. Our data provide validation and guidance for the use of the cumulative logistic model, median regression, generalized pairwise comparisons, and the conditional and truncated approach in specific scenarios.
Abstract
Rev Bras Ter Intensiva. 2012;24(2):157-161
DOI 10.1590/S0103-507X2012000200010
OBJECTIVE: Because patients hospitalized in intensive care units are at risk for poor nutrition, and nutritional therapy is not always started at an appropriate time, the present study aimed to correlate nutritional status, early nutrition, and hyperglycemia with patient mortality in an intensive care unit. METHODS: This archival cohort study used the secondary database of 453 patients who stayed at least 48 hours in an intensive care unit and were assessed for 8 days of hospitalization. Patient nutritional status was defined according to the body mass index. Early nutrition was defined as an feeding energy within the first 48 hours of hospitalization, regardless of the administration route. Blood glucose levels were monitored using a glucometer. RESULTS: A majority of patients were male (54.2%), and approximately half of patients were overweight (48.4%). At the end of the first 48 hours, 69.4% of patients had received nutrition, and only 13.5% of patients still exhibited hyperglycemia. The patients who received early nutritional therapy exhibited lower a mortality risk (p = 0.002), regardless of the presence of other factors associated with mortality. CONCLUSIONS: The significant correlation between early nutritional therapy and survival emphasizes the importance of nutrition in severely ill patients. The low frequency of hyperglycemia found in this study might indicate that the prescription of nutritional therapy and the application of an insulin protocol are appropriate at institutional intensive care units.
Abstract
Rev Bras Ter Intensiva. 2012;24(2):157-161
DOI 10.1590/S0103-507X2012000200010
OBJECTIVE: Because patients hospitalized in intensive care units are at risk for poor nutrition, and nutritional therapy is not always started at an appropriate time, the present study aimed to correlate nutritional status, early nutrition, and hyperglycemia with patient mortality in an intensive care unit. METHODS: This archival cohort study used the secondary database of 453 patients who stayed at least 48 hours in an intensive care unit and were assessed for 8 days of hospitalization. Patient nutritional status was defined according to the body mass index. Early nutrition was defined as an feeding energy within the first 48 hours of hospitalization, regardless of the administration route. Blood glucose levels were monitored using a glucometer. RESULTS: A majority of patients were male (54.2%), and approximately half of patients were overweight (48.4%). At the end of the first 48 hours, 69.4% of patients had received nutrition, and only 13.5% of patients still exhibited hyperglycemia. The patients who received early nutritional therapy exhibited lower a mortality risk (p = 0.002), regardless of the presence of other factors associated with mortality. CONCLUSIONS: The significant correlation between early nutritional therapy and survival emphasizes the importance of nutrition in severely ill patients. The low frequency of hyperglycemia found in this study might indicate that the prescription of nutritional therapy and the application of an insulin protocol are appropriate at institutional intensive care units.
