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Objective To investigate the effect of circadian heart rate variation on short-term and long-term mortality in intensive care unit (ICU) patients. Methods A retrospective cohort study was conducted. A total of 32 536 ICU patients were recorded from 2001 to 2008 published by Multiparameter Intelligent Monitoring in Intensive Care Ⅱ(MIMIC-Ⅱ v2.6) in April 2011. The circadian heart rate variation was defined as the ratio of mean nighttime (23:00 to 07:00) heart rate to mean daytime (07:00 to 23:00) heart rate. The 28-day mortality and 1-year mortality were defined as outcome events. The information such as age, gender, ethnicity, first sequential organ failure assessment (SOFA) score, first simplified acute physiology score Ⅰ (SAPSⅠ), usage of sedatives and catecholamines within 24 hours admission of ICU, clinical complications [hypertension, chronic obstructive pulmonary disease (COPD), diabetes with or without complications, congestive heart failure, liver disease, renal failure, etc.], and the complete heart rate records within 24 hours after ICU admission were collected. Cox proportional risk regression models were used to investigate the association between circadian heart rate variation and 28-day mortality and 1-year mortality in ICU patients. Besides, subgroup analysis was also performed in patients with different first SOFA scores. Results Totally 15 382 ICU patients in MIMIC-Ⅱ database were enrolled, excluding the patients without heart rate records or death records, using pacemaker with arrhythmia, without SOFA or SAPSⅠ score records. Finally, 9 439 patients were enrolled in the study cohort. ① Cox regression analysis of the whole patient showed that the higher circadian heart rate variation was correlated with the increased 28-day mortality [hazard ratio (HR) = 1.613, 95% confidence interval (95%CI) was 1.338-1.943, P < 0.001] and 1-year mortality (HR = 1.573, 95%CI was 1.296-1.908, P < 0.001). After adjustment for demographic factors (age, gender and ethnicity), severity of illness (SOFA and SAPS Ⅰ scores), clinical complications (hypertension, COPD, diabetes with or without complications, congestive heart failure, liver disease, renal failure, etc.), and influence of medications (sedatives and catecholamines), the night-day heart rate ratio was also correlated with 28-day mortality (HR = 1.256, 95%CI was 1.018-1.549, P = 0.033) and 1-year mortality (HR = 1.249, 95%CI was 1.010-1.545, P = 0.040). ② According to the SOFA score (median value of 5), the patients were divided into two subgroups, in which 5 478 patients with SOFA score ≤ 5 and 3 961 patients with SOFA score > 5. Cox regression subgroup analysis showed that circadian heart rate variation was related with higher 28-day mortality (HR = 1.430, 95%CI was 1.164-1.756, P = 0.001) and 1-year mortality (HR = 1.393, 95%CI was 1.123-1.729, P = 0.003) in patients with SOFA score > 5. After adjustment for covariates, the 28-day mortality (HR = 1.279, 95%CI was 1.032-1.584, P = 0.025) and 1-year mortality (HR = 1.255, 95%CI was 1.010-1.558, P = 0.040) also increased with the increasing of night-day heart rate ratio in patients with SOFA score > 5. However, the relationships did not exist in patients with SOFA score ≤ 5. Conclusion In ICU patients, the 28-day mortality and 1-year mortality increase with the higher circadian heart rate variation, which indicates that the circadian heart rate variation in ICU patients is positively correlated with the short-term and long-term mortality, especially in patients with relatively severe illness.
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Objective@#To investigate the effect of circadian heart rate variation on short-term and long-term mortality in intensive care unit (ICU) patients.@*Methods@#A retrospective cohort study was conducted. A total of 32 536 ICU patients were recorded from 2001 to 2008 published by Multiparameter Intelligent Monitoring in Intensive Care Ⅱ (MIMIC-Ⅱ v2.6) in April 2011. The circadian heart rate variation was defined as the ratio of mean nighttime (23:00 to 07:00) heart rate to mean daytime (07:00 to 23:00) heart rate. The 28-day mortality and 1-year mortality were defined as outcome events. The information such as age, gender, ethnicity, first sequential organ failure assessment (SOFA) score, first simplified acute physiology score Ⅰ (SAPSⅠ), usage of sedatives and catecholamines within 24 hours admission of ICU, clinical complications [hypertension, chronic obstructive pulmonary disease (COPD), diabetes with or without complications, congestive heart failure, liver disease, renal failure, etc.], and the complete heart rate records within 24 hours after ICU admission were collected. Cox proportional risk regression models were used to investigate the association between circadian heart rate variation and 28-day mortality and 1-year mortality in ICU patients. Besides, subgroup analysis was also performed in patients with different first SOFA scores.@*Results@#Totally 15 382 ICU patients in MIMIC-Ⅱ database were enrolled, excluding the patients without heart rate records or death records, using pacemaker with arrhythmia, without SOFA or SAPSⅠ score records. Finally, 9 439 patients were enrolled in the study cohort. ① Cox regression analysis of the whole patient showed that the higher circadian heart rate variation was correlated with the increased 28-day mortality [hazard ratio (HR) = 1.613, 95% confidence interval (95%CI) was 1.338-1.943, P < 0.001] and 1-year mortality (HR = 1.573, 95%CI was 1.296-1.908, P < 0.001). After adjustment for demographic factors (age, gender and ethnicity), severity of illness (SOFA and SAPS Ⅰ scores), clinical complications (hypertension, COPD, diabetes with or without complications, congestive heart failure, liver disease, renal failure, etc.), and influence of medications (sedatives and catecholamines), the night-day heart rate ratio was also correlated with 28-day mortality (HR = 1.256, 95%CI was 1.018-1.549, P = 0.033) and 1-year mortality (HR = 1.249, 95%CI was 1.010-1.545, P = 0.040). ② According to the SOFA score (median value of 5), the patients were divided into two subgroups, in which 5 478 patients with SOFA score ≤ 5 and 3 961 patients with SOFA score > 5. Cox regression subgroup analysis showed that circadian heart rate variation was related with higher 28-day mortality (HR = 1.430, 95%CI was 1.164-1.756, P = 0.001) and 1-year mortality (HR = 1.393, 95%CI was 1.123-1.729, P = 0.003) in patients with SOFA score > 5. After adjustment for covariates, the 28-day mortality (HR = 1.279, 95%CI was 1.032-1.584, P = 0.025) and 1-year mortality (HR = 1.255, 95%CI was 1.010-1.558, P = 0.040) also increased with the increasing of night-day heart rate ratio in patients with SOFA score > 5. However, the relationships did not exist in patients with SOFA score ≤ 5.@*Conclusion@#In ICU patients, the 28-day mortality and 1-year mortality increase with the higher circadian heart rate variation, which indicates that the circadian heart rate variation in ICU patients is positively correlated with the short-term and long-term mortality, especially in patients with relatively severe illness.
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The mortality rate of older patients with intertrochanteric fractures has been increasing with the aging of populations in China. The purpose of this study was: 1) to develop an artificial neural network (ANN) using clinical information to predict the 1-year mortality of elderly patients with intertrochanteric fractures, and 2) to compare the ANN's predictive ability with that of logistic regression models. The ANN model was tested against actual outcomes of an intertrochanteric femoral fracture database in China. The ANN model was generated with eight clinical inputs and a single output. ANN's performance was compared with a logistic regression model created with the same inputs in terms of accuracy, sensitivity, specificity, and discriminability. The study population was composed of 2150 patients (679 males and 1471 females): 1432 in the training group and 718 new patients in the testing group. The ANN model that had eight neurons in the hidden layer had the highest accuracies among the four ANN models: 92.46 and 85.79% in both training and testing datasets, respectively. The areas under the receiver operating characteristic curves of the automatically selected ANN model for both datasets were 0.901 (95%CI=0.814-0.988) and 0.869 (95%CI=0.748-0.990), higher than the 0.745 (95%CI=0.612-0.879) and 0.728 (95%CI=0.595-0.862) of the logistic regression model. The ANN model can be used for predicting 1-year mortality in elderly patients with intertrochanteric fractures. It outperformed a logistic regression on multiple performance measures when given the same variables.
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PURPOSE: The purpose of this study was to determine the mortality at postoperative one year & the factors related to mortality for patients who are over 65 years old and who have a hip fracture. MATERIALS AND METHODS: The subjects of this study were 298 patients older than 65 years and who were operated on by one surgeon from 1995 to 2009. RESULTS: The one-year mortality rate for the over 65 years old patients with hip fracture was 15.8%. The one-year ortality rate was significantly related with the number of underlying diseases and with age of over 80 years old, but not with gender, the cause of trauma, the type of fracture, the operative methods, previous activity & the severity of osteoporosis. We found that 21.3% of the overall deaths occurred within 1 month and 57.5% of that occurred within 3 months. CONCLUSION: The one-year mortality rate for the over 65 years old patients was 15.8%. The 1 year mortality rate for the over 65 years old patients was highly affected by the number of underlying diseases and an age of over 80 years old. As the majority of deaths occur within 3 months, intensive care is important during this period.
Subject(s)
Humans , Hip , Critical Care , OsteoporosisABSTRACT
PURPOSE: We wanted to evaluate the factors that influence the one-year mortality rate after bipolar hemiarthroplasty in elderly patients over 90 years of age and who had hip fractures. MATERIALS AND METHODS: In this retrospective study, we enrolled 42 cases (29 females and 12 males) that were treated by bipolar hemiarthroplasty for hip fractures between April 1999 and April 2008. The mean age was 94 (range: 90~101) years. We compared such variables as age, gender, BMD (bone mineral density), the ASA (American Society of Anesthesiologists) score, the type of fracture, the operation time, the type of anesthesia, the length of the ICU (intensive care unit) care, the length of hospitalization, operative delay and the postoperative ambulatory capability between the one-year mortality group and the control group (alive over a minimum of 1-year), and we investigated the risk factors related to one-year mortality. RESULTS: The one-year mortality rate was 32%. There were significant relationships between the postoperative one-year mortality and the ASA score, the length of the ICU care, operative delay and the postoperative ambulatory capability. The one-year mortality rate in the trochanteric fracture group was significantly higher than that in the neck fracture group. However, there were no relationships between the one-year mortality and age, gender, BMD, the length of operation, the type of anesthesia and the length of the hospitalization. CONCLUSION: The preoperative ASA score was significantly higher in the one-year mortality group among the elderly patients over 90 years of age and who were treated with bipolar hemiarthroplasty for hip fractures. The length of the ICU care, operative delay and the postoperative ambulatory capability were significantly associated with one-year mortality, and so all of these should be considered as postoperative prognostic factors.