Prevalence and intervention of preoperative anemia in Chinese adults: A retrospective cross-sectional study based on national preoperative anemia database

The association between preoperative lacunar infarcts and postoperative delirium in elderly patients undergoing major abdominal surgery: a prospective cohort study

OBJECTIVE

The primary goal was to investigate whether the presence of preoperative lacunar infarcts (LACI) was associated with postoperative delirium (POD) in elderly patients undergoing elective major abdominal surgery.

DESIGN

A prospective cohort study.

SETTING AND PARTICIPANTS

Patients aged ≥ 65 years from a tertiary level A hospital in China.

METHODS

The POD was assessed once daily within the first postoperative 3 days using the Confusion Assessment Method. Neurocognitive tests using the Mini-mental State Examination (MMSE) and the Beijing version of the Montreal Cognitive Assessment scales were carried out within 3 days before surgery and 4-7 days after surgery. Regional cerebral oxygen saturation (rScO2) was recorded in the operating room. Logistic regression analysis was used to evaluate the impact of preoperative LACI on POD and to explore the risk factors for POD.

RESULTS

A total of 369 participants were analyzed, 161 in the preoperative LACI-positive group (P group), and 208 in the preoperative LACI-negative group (N group), respectively. The incidence of POD was 32.7% in our study. The incidence of POD was significantly higher in the P group than in the N group (39.1 vs 27.9%, risk ratio, 1.66; 95% CI 1.07-2.58; P = 0.022). Furthermore, the P group exhibited lower mean rScO2 values during the procedure (P < 0.001). In exploratory analysis, the advanced age (P = 0.005), sex (P = 0.038), and lower preoperative MMSE score (P = 0.019) were independent risk factors for POD in patients undergoing major abdominal surgery.

CONCLUSIONS AND IMPLICATIONS

Preoperative LACI was common, and constituted a risk factor for POD in older patients undergoing abdominal surgery. Despite the frequent subclinical nature, the preoperative LACI led to lower mean rScO2 during the procedure. These findings could help early identification of high-risk POD patients.

The association between preoperative anemia and postoperative mortality among non-cardiac surgical patients in Northwest Ethiopia: a prospective cohort study

INTRODUCTION

In a low-income country, the impact of preoperative anemia on postoperative mortality among noncardiac surgery patients is little understood. As a result, we aim to investigate the association between preoperative anemia and postoperative mortality in noncardiac surgery patients in Northwest Ethiopia.

METHODS

This is a prospective follow-up study of 3506 noncardiac surgery patients who were included in the final analysis between June 1, 2019, and July 1, 2021. We used a propensity score-match analysis to group anemic and non-anemic patients. The propensity score match analysis took into account age, gender, comorbidities, American Society of Anesthesiologists physical status, urgency of surgery, and trauma. Patients with and without preoperative anemia were divided into a 1:1 ratio in a propensity score balance. The association between preoperative anemia and postoperative mortality was determined using adjusted odds ratios and 95% confidence interval.

RESULTS

This study included 3506 noncardiac surgery patients, of which 1532 (43.7%) had preoperative anemia. The propensity score-matching results reveal that one-to-one nearest neighbour propensity score matching without replacement was successful for 1351 pairs of surgical patients. The postoperative 28-day mortality rate for anemic patients was 53 (3.9%), with (OR:1.63; 95% CI: 1.05-2.54).

CONCLUSION

The study found that patients undergoing noncardiac surgery in Northwest Ethiopia had a higher rate of preoperative anemia than those in high-income countries. Preoperative anemia had a significant association with 28-day mortality after surgery.

Magnitude and associated factors of preoperative anemia among adult elective surgical patients at Saint Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia, 2024

Background

Preoperative anemia is a common hematologic public health problem among elective surgical patients. Preoperative anemia complications independently increase the risk of perioperative complications and mortality rate. Despite this complication, there is a scarcity of evidence on the prevalence and associated factors of preoperative anemia among adult elective surgical patients in Ethiopia. Therefore, this study aimed to investigate the magnitude and associated factors of preoperative anemia among adult elective surgical patients at Saint Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia.

Methods

An institution-based cross-sectional study was conducted from January 1 to 30, 2024 at Saint Paul's Hospital Millennium Medical College. A consecutive sampling technique was used to select eligible study participants. Chart review and a structured, pretested, and interviewer-administered questionnaire were employed. Kobo toolbox was used to collect the data and exported to SPSS version 25 software for data cleaning, coding, and analysis. Binary logistic regression model was fitted to identify factors associated with preoperative anemia. An adjusted odds ratio (AOR) with its 95% CI and a p-value of ≤0.05 was used to declare a statistical association.

Results

A total of 247 study participants were included in the analysis, giving a response rate of 98.8%. Majority (68%) of the participants were from urban areas. The median age of the patient was 38 (IQR ± 32) years. The magnitude of preoperative anemia was found to be 27.1% (95% CI: 21.9, 33.1). Being female (AOR = 3.44; 95%CI: 1.53, 7.73), being overweight (AOR = 0.26; 95%CI: 0.10, 0.88), and having infection and injury/trauma as indications for surgery (AOR = 4.59; 95%CI: 1.62, 12.96) and (AOR = 3.58; 95%CI: 1.35, 9.49) were significantly associated with preoperative anemia.

Conclusion

In this study, more than one-fourth of the study participants had preoperative anemia. To decrease this public health problem, it is better to screen at risk patients, specifically females and trauma patients during the preoperative visit and disseminate information about a healthy diet and the prevention and treatment of anemia through health education.

Relationship between preoperative hemoglobin levels and length of stay in elderly patients with hip fractures: A retrospective cohort study

Globally, hip fractures in elderly individuals are a prevalent and serious issue. Patients typically have a longer length of stay (LOS), which increases the risk of complications and increases hospitalization costs. Hemoglobin (Hb) is a routine blood test that is associated with disease prognosis. This study aimed to investigate the relationship between preoperative Hb and LOS in elderly hip fracture patients and to determine a reliable transfusion threshold. The clinical data of hip fracture patients (aged ≥ 60 years) admitted to the Department of Orthopaedics, Shenzhen Second People's Hospital, between January 2012 and December 2021 were retrospectively analyzed. Multiple linear regression analysis was used to assess the linear relationship between preoperative Hb and LOS. Smooth curve fitting was performed to investigate potential nonlinear relationships. In the case of discovering nonlinear relationships, a weighted two-piecewise linear regression model was built, and the inflection points were determined using a recursive algorithm. Subgroup analyses were conducted based on age and gender. A total of 1444 patients with an average age of (77.54 ± 8.73) years were enrolled. After adjusting for covariates, a nonlinear relationship was found between preoperative Hb and LOS. The two-piecewise linear regression model revealed an inflection point of 10 g/dL. On the left of the inflection point (Hb < 10 g/dL), the LOS was reduced by 0.735 days for every 1 g/dL increase in Hb (β = -0.735, 95% confidence interval: -1.346 to -0.124, P = .019). On the right side of the inflection point (Hb > 10 g/dL), the relationship was not statistically significant (β = 0.001, 95% confidence interval: -0.293 to 0.296, P = .992). In elderly hip fracture patients, there is a nonlinear association between preoperative Hb and LOS. However, when Hb levels were <10 g/dL, there was a negative correlation with the LOS. No correlation was observed when Hb levels were >10 g/dL. These findings underscore the importance of timely intervention to manage Hb levels in elderly patients with hip fractures, potentially reducing hospitalization durations and associated complications.

[Impact of anemia on incidence of perioperative lower limb deep vein thrombosis in patients undergoing total hip arthroplasty]

Objective

To explore the impact of anemia on the incidence of perioperative lower limb deep vein thrombosis (DVT) in patients undergoing total hip arthroplasty (THA).

Methods

A retrospective analysis was conducted on clinical data of 1 916 non-fracture patients who underwent THA between September 2015 and December 2021, meeting the selection criteria. Among them, there were 811 male and 1 105 female patients, aged between 18 and 94 years with an average of 59.2 years. Among the patients, 213 were diagnosed with anemia, while 1 703 were not. Preoperative DVT was observed in 55 patients, while 1 861 patients did not have DVT preoperatively (of which 75 patients developed new-onset DVT postoperatively). Univariate analysis was performed on variables including age, gender, body mass index (BMI), diabetes, hypertension, history of tumors, history of thrombosis, history of smoking, revision surgery, preoperative D-dimer positivity (≥0.5 mg/L), presence of anemia, operation time, intraoperative blood loss, transfusion requirement, and pre- and post-operative levels of red blood cells, hemoglobin, hematocrit, and platelets. Furthermore, logistic regression was utilized for multivariate analysis to identify risk factors associated with DVT formation.

Results

Univariate analysis showed that age, gender, hypertension, revision surgery, preoperative levels of red blood cells, preoperative hemoglobin, preoperative D-dimer positivity, and anemia were influencing factors for preoperative DVT ( P<0.05). Further logistic regression analysis indicated that age (>60 years old), female, preoperative D-dimer positivity, and anemia were risk factors for preoperative DVT ( P<0.05). Univariate analysis also revealed that age, female, revision surgery, preoperative D-dimer positivity, anemia, transfusion requirement, postoperative level of red blood cells, and postoperative hemoglobin level were influencing factors for postoperative new-onset DVT ( P<0.05). Further logistic regression analysis indicated that age (>60 years old), female, and revision surgery were risk factors for postoperative new-onset DVT ( P<0.05).

Conclusion

The incidence of anemia is higher among patients with preoperative DVT for THA, and anemia is an independent risk factor for preoperative DVT occurrence in THA. While anemia may not be an independent risk factor for THA postoperative new-onset DVT, the incidence of anemia is higher among patients with postoperative new-onset DVT.

Sex-Specific Associations Between Preoperative Hemoglobin and Outcomes After Major Noncardiac Surgery: A Retrospective Cohort Study

BACKGROUND

Preoperative anemia is an established risk factor for morbidity and mortality after surgery. Men and women have different hemoglobin concentrations and are at different risks of postoperative complications. However, sex-stratified analysis on the association between preoperative hemoglobin and outcomes after noncardiac surgery has been limited in previous studies.

METHODS

This was a retrospective cohort study of adult patients undergoing elective major noncardiac surgery in a large academic hospital. The primary outcome was a collapsed composite of postoperative mortality or cardiovascular, renal, pulmonary, and infectious complications during hospitalization. Sex-specific univariable associations between preoperative hemoglobin and the composite outcome were visualized using moving-average and cubic-spline smoothing plots. Multivariable regression models adjusting for patient demographics, comorbidities, medication uses, laboratory tests, and anesthesia/surgery features were used to estimate confounder-adjusted associations. Restricted cubic spline and piecewise linear functions were used to assess the possible nonlinear relationships between preoperative hemoglobin and the outcomes. The interaction between patient sex and hemoglobin on outcomes was assessed using a likelihood-ratio test.

RESULTS

We included 22,550 patients, with 6.7% (622 of 9268) of women and 9.7% (1293 of 13,282) of men developing the primary outcome. Lower preoperative hemoglobin was associated with a higher incidence of the primary composite outcome in both men and women. Nonlinearity for the association was not statistically significant in either women ( P = .539) or men ( P = .165). The multivariable-adjusted odds ratios per 1 g/dL increase in hemoglobin were 0.93 (95% confidence interval [CI], 0.87-0.98; P = .013) for women and 0.94 (95% CI, 0.90-0.97; P < .001) for men, with no interaction by sex ( Pinteraction = .923). No hemoglobin thresholds were confirmed at which the associations with the primary outcome changed significantly.

CONCLUSIONS

Low preoperative hemoglobin was associated with a higher risk of complications or mortality after elective noncardiac surgery in both men and women. No differences in the strength of associations between sexes were found. Further studies are needed to assess whether these associations are linear or there are sex-specific thresholds of preoperative hemoglobin concentrations below which postoperative risks begin to increase.

Temporal trends and geographic variations in perioperative red blood cell transfusion in major surgical procedures from 2013 to 2018 in China

BACKGROUND AND OBJECTIVES

Transfusion-related guidelines promote restrictive blood transfusion. However, whether these guidelines have been successfully translated into clinical practice in China is unknown. This study aimed to provide updated information about the temporal trends in the prevalence of perioperative red blood cell (RBC) transfusion in China.

MATERIALS AND METHODS

We analysed data from the Hospital Quality Monitoring System database (2013-2018) to investigate the prevalence of perioperative RBC transfusion in patients undergoing craniotomy for cerebral aneurysms or arteriovenous malformations, sternotomy for mitral valve replacement, open thoracotomy lobectomy, open gastrectomy and hip arthroplasty. Mixed-effects logistic regression models quantified the likelihood of RBC transfusions.

RESULTS

The study included 438,183 patients, with 44,697 (10.20%) receiving perioperative RBC transfusions. Introducing transfusion-related guidelines in China markedly decreased the prevalence of RBC transfusion among patients who underwent major surgical procedures in the following years. The prevalence of RBC transfusion for hip arthroplasty was 17.34% in 2013 and 7.03% in 2018. After adjusting for patient risk factors, the odds ratio of RBC transfusion for hip arthroplasty was significantly lower in 2018 (0.74, 95% confidence intervals [CI] 0.53-1.02) than in 2013 (1.84, 95% CI 1.37-2.48).

CONCLUSION

The prevalence of perioperative RBC transfusion decreased from 2013 to 2018 in China, supporting the potential beneficial effects of transfusion-related guidelines. Considering the geographic variations in RBC transfusion, reducing heterogeneity may impact public health by improving surgical outcomes.

Prediction of red blood cell transfusion after orthopedic surgery using an interpretable machine learning framework

Objective

Postoperative red blood cell (RBC) transfusion is widely used during the perioperative period but is often associated with a high risk of infection and complications. However, prediction models for RBC transfusion in patients with orthopedic surgery have not yet been developed. We aimed to identify predictors and constructed prediction models for RBC transfusion after orthopedic surgery using interpretable machine learning algorithms.

Methods

This retrospective cohort study reviewed a total of 59,605 patients undergoing orthopedic surgery from June 2013 to January 2019 across 7 tertiary hospitals in China. Patients were randomly split into training (80%) and test subsets (20%). The feature selection method of recursive feature elimination (RFE) was used to identify an optimal feature subset from thirty preoperative variables, and six machine learning algorithms were applied to develop prediction models. The Shapley Additive exPlanations (SHAP) value was employed to evaluate the contribution of each predictor towards the prediction of postoperative RBC transfusion. For simplicity of the clinical utility, a risk score system was further established using the top risk factors identified by machine learning models.

Results

Of the 59,605 patients with orthopedic surgery, 19,921 (33.40%) underwent postoperative RBC transfusion. The CatBoost model exhibited an AUC of 0.831 (95% CI: 0.824-0.836) on the test subset, which significantly outperformed five other prediction models. The risk of RBC transfusion was associated with old age (>60 years) and low RBC count (<4.0 × 10¹²/L) with clear threshold effects. Extremes of BMI, low albumin, prolonged activated partial thromboplastin time, repair and plastic operations on joint structures were additional top predictors for RBC transfusion. The risk score system derived from six risk factors performed well with an AUC of 0.801 (95% CI: 0.794-0.807) on the test subset.

Conclusion

By applying an interpretable machine learning framework in a large-scale multicenter retrospective cohort, we identified novel modifiable risk factors and developed prediction models with good performance for postoperative RBC transfusion in patients undergoing orthopedic surgery. Our findings may allow more precise identification of high-risk patients for optimal control of risk factors and achieve personalized RBC transfusion for orthopedic patients.

Prediction of Long-Term Recovery From Disability Using Hemoglobin-Based Models: Results From a Cohort of 1,392 Patients Undergoing Spine Surgery

Hemoglobin and its associated blood values are important laboratory biomarkers that mirror the strength of constitution of patients undergoing spine surgery. Along with the clinical determinants available during the preadmission visit, it is important to explore their potential for predicting clinical success from the patient's perspective in order to make the pre-admission visit more patient-centered. We analyzed data from 1,392 patients with spine deformity, disc disease, or spondylolisthesis enrolled between 2016 and 2019 in our institutional Spine Registry. Patient-reported outcome measure at 17 months after surgery was referred to the Oswestry disability index. High preoperative hemoglobin was found to be the strongest biochemical determinant of clinical success along with high red blood cells count, while low baseline disability, prolonged hospitalization, and long surgical times were associated with poor recovery. The neural network model of these predictors showed a fair diagnostic performance, having an area under the curve of 0.726 and a sensitivity of 86.79%. However, the specificity of the model was 15.15%, thus providing to be unreliable in forecasting poor patient-reported outcomes. In conclusion, preoperative hemoglobin may be one of the key biomarkers on which to build appropriate predictive models of long-term recovery after spine surgery, but it is necessary to include multidimensional variables in the models to increase the reliability at the patient's level.

Intravenous iron for the treatment of iron deficiency anemia in China: a patient-level simulation model and cost-utility analysis comparing ferric derisomaltose with iron sucrose

OBJECTIVES

Two intravenous (IV) iron formulations, ferric derisomaltose (FDI) and iron sucrose (IS), are currently available for the treatment of iron deficiency anemia (IDA) in China. Clinical studies have demonstrated that FDI has an improved efficacy and safety profile versus IS, while requiring fewer infusions to correct iron deficits. Based on these findings, the present study evaluated the costs and benefits of FDI and IS for the treatment of IDA, from a healthcare system and societal perspective in China.

METHODS

A patient-level model was developed to project time to hematological response and incidence of cardiovascular adverse events and hypersensitivity reactions (HSRs) associated with FDI and IS over 5 years. Costs included iron acquisition, administration, and adverse event/HSR treatment costs, based on published studies, fee schedules, and a physician survey. Health state utilities associated with adverse events, HSRs, and the number of infusions were obtained from the literature and a time trade-off survey.

RESULTS

From a healthcare system perspective, FDI was associated with incremental costs of RMB 1,934 (purchasing power parity USD 462) and incremental quality-adjusted life expectancy of 0.078 quality-adjusted life-years (QALYs) versus IS, yielding an incremental cost-utility ratio of RMB 24,901 (USD 5,949) in the base case scenario. From a societal perspective, FDI was associated with reduced total costs and therefore dominant versus IS.

LIMITATIONS

Limitations included the absence of clinical data specific to China and insufficient data to model persistence with treatment.

CONCLUSIONS

This was the first cost-utility analysis comparing FDI and IS for the treatment of IDA in China. Based on a patient-level model, FDI was found to improve quality of life and reduce administration and adverse events costs relative to IS. Using the 2020 Chinese gross domestic product per capita of RMB 72,447 (USD 17,307) as a cost-effectiveness threshold, FDI would be considered cost-effective in China.