Estimating the risk thresholds used by guidelines to recommend postpartum thromboprophylaxis

Guideline-based venous thromboprophylaxis in postpartum women: An in-depth evaluation of ACOG and RCOG recommendations and real-life implementation

OBJECTIVES

Venous thromboembolism is one of the most serious complications of the postpartum period, and international societies have various thromboprophylaxis guidelines for its prevention. This study compares postpartum venous thromboprophylaxis recommendations from the American College of Obstetrics and Gynecology (ACOG) and the Royal College of Obstetricians and Gynecologists (RCOG) with real-life clinical practices.

STUDY DESIGN

Data analysis of 1000 postpartum women at a tertiary care center focused on patient demographics, venous thromboembolism risk factors, and clinical thromboprophylaxis practices. Patient-specific risk factors were compared between ACOG and RCOG guidelines, assessing Low-Molecular-Weight-Heparin dosages and durations. Guideline compliance, undertreatment/overtreatment rates, and the required number of prefilled Low-Molecular-Weight-Heparin syringes were evaluated.

RESULTS

Significant discrepancies were observed between ACOG and RCOG guidelines, particularly in Low Molecular Weight Heparin dosages and durations. Consensus rates with clinical approaches were around 53%, with inconsistencies leaning towards undertreatment (RCOG) and overtreatment (ACOG). The number of required prefilled Low-Molecular-Weight-Heparin syringes was notably higher according to RCOG compared to ACOG guidelines.

CONCLUSION

Postpartum Venous thromboembolism prophylaxis guidelines from American College of Obstetrics and Gynecology and Royal College of Obstetricians and Gynecologists exhibit substantial differences, leading to variations in clinical practice. Further research on the significance of Venous thromboembolism risk factors is essential for improving risk assessment tools and refining guideline recommendations for pregnancy-related Venous thromboembolism prevention.

Preferences of pregnant women for postpartum thromboprophylaxis: the bicentric PREFER-PostPartum study

BACKGROUND

Clinical guidelines for postpartum thromboprophylaxis differ due to its uncertain effect and varying preferences of experts. Women's preferences for postpartum thromboprophylaxis are unknown, although they may inform practices and future research.

OBJECTIVES

Our aim was to elicit the pregnant women's preferences for postpartum thromboprophylaxis according to different risks of venous thromboembolism (VTE) and bleeding.

METHODS

In 2 Swiss and French maternity hospitals, we conducted structured interviews of pregnant or postpartum women. Participants were instructed on pulmonary embolism, deep vein thrombosis, postpartum hemorrhage, and subcutaneous injections of low-molecular-weight heparin (LMWH). First, we randomized women to either standard gamble or time trade-off (2 different validated methods) to estimate the utilities (quality of life, from 0 to 1) of these health states. Second, we elicited the preference for the use of short-term postpartum thromboprophylaxis with LMWH vs none across different risks of postpartum VTE and bleeding through direct-choice exercises.

RESULTS

Among 122 participants, median (IQR) health state utilities were 0.725 (0.30-0.925) for pulmonary embolism, 0.75 (0.40-0.97) for postpartum hemorrhage, 0.85 (0.60-0.97) for deep vein thrombosis, and 0.96 (0.96-0.999) for LMWH injections. The median risk of postpartum VTE for preference of the use of postpartum thromboprophylaxis over no treatment was 0.1% (IQR, 0.01%-0.50%) without LMWH-associated bleeding risk and 0.2% (IQR, 0.1%-5%) with a 1% bleeding risk.

CONCLUSION

European pregnant women appear to have a high willingness for 10-day postpartum thromboprophylaxis, preferred over no treatment even for low risks of postpartum VTE. This perspective from patients supports the urgent need for a randomized trial evaluating the efficacy and safety of postpartum thromboprophylaxis.

Postpartum pharmacologic thromboprophylaxis and complications in a US cohort

BACKGROUND

Venous thromboembolism accounts for approximately 9% of pregnancy-related deaths in the United States. National guidelines recommend postpartum risk stratification and pharmacologic prophylaxis in at-risk individuals. Knowledge on modern rates of postpartum pharmacologic thromboprophylaxis and its associated risks is limited.

OBJECTIVE

This study aimed to describe the rate of, and factors associated with, initiation of postpartum pharmacologic prophylaxis for venous thromboembolism, and to assess associated adverse outcomes.

STUDY DESIGN

This was a secondary analysis of a multicenter cohort of individuals delivering on randomly selected days at 17 US hospitals (2019-2020). Medical records were reviewed by trained and certified personnel. Those with an antepartum diagnosis of venous thromboembolism, receiving antepartum anticoagulation, or known SARS-CoV-2 infection were excluded. The primary outcome was use of postpartum pharmacologic thromboprophylaxis. Secondary outcomes included bleeding complications, surgical site infection, hospital readmission, and venous thromboembolism through 6 weeks postpartum. The rate of thromboprophylaxis administration was assessed by mode of delivery, institution, and continuance to the outpatient setting. Multivariable regression models were developed using k-fold cross-validation with stepwise backward elimination to evaluate factors associated with thromboprophylaxis administration. Univariable and multivariable logistic models with propensity score covariate adjustment were performed to assess the association between thromboprophylaxis administration and adverse outcomes.

RESULTS

Of 21,114 individuals in the analytical cohort, 11.9% (95% confidence interval, 11.4%-12.3%) received postpartum pharmacologic thromboprophylaxis; the frequency of receipt was 29.8% (95% confidence interval, 28.7%-30.9%) following cesarean and 3.5% (95% confidence interval, 3.2%-3.8%) following vaginal delivery. Institutional rates of prophylaxis varied from 0.21% to 34.8%. Most individuals (83.3%) received thromboprophylaxis only as inpatients. In adjusted analysis, cesarean delivery (adjusted odds ratio, 19.17; 95% confidence interval, 16.70-22.00), hysterectomy (adjusted odds ratio, 15.70; 95% confidence interval, 4.35-56.65), and obesity (adjusted odds ratio, 3.45; 95% confidence interval, 3.02-3.95) were the strongest factors associated with thromboprophylaxis administration. Thromboprophylaxis administration was not associated with surgical site infection (0.9% vs 0.6%; odds ratio, 1.48; 95% confidence interval, 0.80-2.74), bleeding complications (0.2% vs 0.1%; odds ratio, 2.60; 95% confidence interval, 0.99-6.80), or postpartum readmission (0.9% vs 0.3%; adjusted odds ratio, 1.38; 95% confidence interval, 0.68-2.81). The overall rate of venous thromboembolism was 0.06% (95% confidence interval, 0.03%-0.10%) and was higher in those receiving prophylaxis (0.2%) compared with those not receiving prophylaxis (0.04%).

CONCLUSION

Approximately 1 in 10 patients received postpartum pharmacologic thromboprophylaxis in this US cohort. Rates of prophylaxis varied widely by institution. Cesarean delivery, hysterectomy, and obesity were predominant factors associated with postpartum thromboprophylaxis administration.

VTE Risk Assessment and Prevention in Pregnancy

Venous thromboembolism (VTE) remains the leading cause of maternal mortality in pregnancy and the postpartum period. In addition to the higher pregnancy-associated baseline VTE risk, there are several well-established risk factors that can further increase the risk of VTE. At present, a thorough interrogation of these risk factors remains our only tool for estimating which pregnant people may be at an increased risk of VTE, and thus potentially benefit from thromboprophylaxis. However, an important knowledge gap still exists surrounding the duration of increased risk and the interaction of risk factors with each other. Furthermore, up to now, once significant risk has been established, prevention strategies have been largely based on expert opinion rather than high-quality data. Recent trials have successfully bridged a proportion of this knowledge gap; however, the challenge of conducting high-quality clinical trials with pregnant people remains. In this article, we provide an update on the recent evidence surrounding VTE risk factors in pregnancy while concurrently outlining knowledge gaps and current approaches to VTE prevention.

Thromboprophylaxis during pregnancy and the puerperium: a systematic review and economic evaluation to estimate the value of future research

Background

Pharmacological prophylaxis to prevent venous thromboembolism is currently recommended for women assessed as being at high risk of venous thromboembolism during pregnancy or in the 6 weeks after delivery (the puerperium). The decision to provide thromboprophylaxis involves weighing the benefits, harms and costs, which vary according to the individual's venous thromboembolism risk. It is unclear whether the United Kingdom's current risk stratification approach could be improved by further research.

Objectives

To quantify the current decision uncertainty associated with selecting women who are pregnant or in the puerperium for thromboprophylaxis and to estimate the value of one or more potential future studies that would reduce that uncertainty, while being feasible and acceptable to patients and clinicians.

Methods

A decision-analytic model was developed which was informed by a systematic review of risk assessment models to predict venous thromboembolism in women who are pregnant or in the puerperium. Expected value of perfect information analysis was used to determine which factors are associated with high decision uncertainty and should be the target of future research. To find out whether future studies would be acceptable and feasible, we held workshops with women who have experienced a blood clot or have been offered blood-thinning drugs and surveyed healthcare professionals. Expected value of sample information analysis was used to estimate the value of potential future research studies.

Results

The systematic review included 17 studies, comprising 19 unique externally validated risk assessment models and 1 internally validated model. Estimates of sensitivity and specificity were highly variable ranging from 0% to 100% and 5% to 100%, respectively. Most studies had unclear or high risk of bias and applicability concerns. The decision analysis found that there is substantial decision uncertainty regarding the use of risk assessment models to select high-risk women for antepartum prophylaxis and obese postpartum women for postpartum prophylaxis. The main source of decision uncertainty was uncertainty around the effectiveness of thromboprophylaxis for preventing venous thromboembolism in women who are pregnant or in the puerperium. We found that a randomised controlled trial of thromboprophylaxis in obese postpartum women is likely to have substantial value and is more likely to be acceptable and feasible than a trial recruiting women who have had a previous venous thromboembolism. In unselected postpartum women and women following caesarean section, the poor performance of risk assessment models meant that offering prophylaxis based on these models had less favourable cost effectiveness with lower decision uncertainty.

Limitations

The performance of the risk assessment model for obese postpartum women has not been externally validated.

Conclusions

Future research should focus on estimating the efficacy of pharmacological thromboprophylaxis in pregnancy and the puerperium, and clinical trials would be more acceptable in women who have not had a previous venous thromboembolism.

Study registration

This study is registered as PROSPERO CRD42020221094.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR131021) and is published in full in Health Technology Assessment; Vol. 28, No. 9. See the NIHR Funding and Awards website for further award information.

VTE risk assessment, prevention and diagnosis in pregnancy

Venous thromboembolism (VTE) is still reported as the leading cause of direct maternal death in pregnancy in serial international reports in developed countries. VTE risk is higher during pregnancy but is further increased by additional well-characterized risk factors. International guidelines recommend that formal VTE risk assessment should be conducted at least in early pregnancy, at delivery and when risk factors change. High quality data supporting optimal VTE prevention strategies are lacking, outside the setting of prevention of VTE recurrence. Moreover, recent high-quality studies have provided much-needed data on diagnostic strategies for pulmonary embolism (PE) in pregnancy. In this review, we summarize knowledge gaps and recently published data in the prevention and diagnosis of VTE in pregnancy. Moreover, we describe ongoing high-quality randomised trials and prospective clinical management studies in this area. High quality clinical studies and trials in pregnancy can be done and must be prioritised, through international network efforts and national funding advocacy. Ultimately, translation of study results to impact upon guidelines and policy will deliver better care to and will protect the lives and health of pregnant people and those contemplating pregnancy throughout the world.

Factors limiting women's adherence to venous thromboembolism prophylaxis after cesarean section in the Gaza Strip: A cross-sectional study

OBJECTIVES

We evaluate the rates and limitations of women's adherence to low molecular weight heparin (LMWH) after cesarean section (CS) in the Gaza Strip.

METHODS

Women who underwent CS were recruited consecutively. Communication offered to women, adherence to Venous thromboembolism (VTE), and its limiting factors were surveyed.

RESULTS

281 women participated (mean age 27.9 years). 51.95% fully adhered to VTE prophylaxis. Causes of suboptimal adherence were: 51.1% did not feel VTE prophylaxis was important, 37.8% due to high drug cost, and 11.1% didn't receive a prescription for LMWH at discharge. Poor communication was evident as 48.8% of the sample did not receive any instructions about the technical method of LMWH injection, 45.6% did not receive any information about the clinical significance of heparin, and 74.7% were unaware of LMWH side effects.

CONCLUSION

There is inadequate adherence to VTE prophylaxis after CS among Gaza women, mostly due to a lack of appropriate communication but also due to drug costs.

Development and validation of a facile rapid assessment scale for perinatal venous thromboembolism in puerperium in Chinese women

BACKGROUND

It is still urgent and challenge to develop a simple risk assessment scale for venous thromboembolism (VTE) in puerperium in Chinese women.

METHODS

The study, a retrospective case-control study, was conducted in 12 hospitals in different cities in China. A total of 1152 pregnant women were selected, including 384 cases with VTE and 768 cases without VTE. A logistic regression method was conducted to determine the risk factors of VTE.

RESULTS

Age, BMI before delivery, gestational diabetes mellitus, family history (thrombosis, diabetes, cardiovascular disease), and assisted reproductive technology were independent risk factors (P<0.05). The difference between the high-risk group and the low-risk group was statistically significant(P<0.001) with a sensitivity of 0.578, specificity of 0.756, Yuden index o.334, and area under the ROC curve of 0.878.

CONCLUSIONS

The age (≥ 35 years), BMI before delivery (≥ 30 kg/m2), gestational diabetes mellitus, family history of related diseases and assisted reproductive technology are more likely to cause VTE after full-time delivery. The simple and rapid assessment scale of VTE in women after full-term delivery has perfect discrimination (P < 0.001), which can be applied to predict the risk of VTE in Chinese full-term postpartum women.

Use of the RCOG risk assessment model and biomarkers to evaluate the risk of postpartum venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality during pregnancy and the puerperium. The vast majority of VTE occurs after childbirth. China has not yet established standard risk assessment model for postpartum venous thromboembolism (VTE), the Royal College of Obstetricians and Gynecologists (RCOG) risk assessment model (RAM) is commonly used in clinic at present. Herein, we aimed to evaluate the validity of the RCOG RAM in the Chinese population and try to formulate a local risk assessment model by combining with other biomarkers for VTE prophylaxis.

METHODS

The retrospective study was conducted from January 2019 to December 2021at Shanghai First Maternity and Infant Hospital which has approximately 30,000 births annually, and the incidence of VTE, differences between RCOG-recommended risk factors, and other biological indicators from medical records were evaluated.

RESULTS

The study included VTE (n = 146) and non-VTE(n = 413) women who examined by imaging for suspicion of postpartum VTE. There was no statistical difference in the incidence rate of postpartum VTE between the low-score group (23.8%) and the high-score group (28%) after stratification by RCOG RAM. However, we found that cesarean section (in the low-score group), white blood cell (WBC) ≥ 8.64*10^9/L (in the high-score group), low-density lipoprotein(LDL) ≥ 2.70 mmol/L, and D-dimer ≥ 3.04 mg/L (in both groups) were highly associated with postpartum VTE. Subsequently, the validity of the RCOG RAM combined with biomarkers as a model for the risk assessment of VTE was estimated and the results showed that this model has good accuracy, sensitivity, and specificity.

CONCLUSIONS

Our study indicated that the RCOG RAM was not the best strategy for predicting postpartum VTE. Combined with some biomarkers (including the value of LDL and D-Dimer, and WBC count), the RCOG RAM is more efficient when identifying high-risk groups of postpartum VTE in the Chinese population.

TRIAL REGISTRATION

This purely observational study does not require registration based on ICMJE guidelines.

Venous thromboembolism risk score during hospitalization in pregnancy: results of 10694 prospective evaluations in a clinical trial

OBJECTIVES

Hospitalization during pregnancy and childbirth increases the risk of Venous Thromboembolism Risk (VTE). This study applied a VTE risk score to all hospitalized pregnant women to ascertain its effectiveness in preventing maternal death from VTE until 3 months after discharge.

METHODS

In this interventional study, patients were classified as low- or high-risk according to the VTE risk score (Clinics Hospital risk score). High-risk patients (score ≥ 3) were scheduled for pharmacological Thromboprophylaxis (TPX). Interaction analysis of the main risk factors was performed using Odds Ratio (OR) and Poisson regression with robust variance.

RESULTS

The data of 10694 cases (7212 patients) were analyzed; 1626 (15.2%, 1000 patients) and 9068 (84.8%, 6212 patients) cases were classified as high-risk (score ≥ 3) and low-risk (score < 3), respectively. The main risk factors (Odds Ratio, 95% Confidence Interval) for VTE were age ≥ 35 and < 40 years (1.6, 1.4-1.8), parity ≥ 3 (3.5, 3.0-4.0), age ≥ 40 years (4.8, 4.1-5.6), multiple pregnancies (2.1, 1.7-2.5), BMI ≥ 40 kg/m² (5.1, 4.3-6.0), severe infection (4.1, 3.3-5.1), and cancer (12.3, 8.8-17.2). There were 10 cases of VTE: 7/1636 (0.4%) and 3/9068 (0.03%) in the high- and low-risk groups, respectively. No patient died of VTE. The intervention reduced the VTE risk by 87%; the number needed to treat was 3.

CONCLUSIONS

This VTE risk score was effective in preventing maternal deaths from VTE, with a low indication for TPX. Maternal age, multiparity, obesity, severe infections, multiple pregnancies, and cancer were the main risk factors for VTE.

Risk assessment models for venous thromboembolism in pregnancy and in the puerperium: a systematic review

OBJECTIVES

To assess the comparative accuracy of risk assessment models (RAMs) to identify women during pregnancy and the early postnatal period who are at increased risk of venous thromboembolism (VTE).

DESIGN

Systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

DATA SOURCES

MEDLINE, Embase, Cochrane Library and two research registers were searched until February 2021.

ELIGIBILITY CRITERIA

All validation studies that examined the accuracy of a multivariable RAM (or scoring system) for predicting the risk of developing VTE in women who are pregnant or in the puerperium (within 6 weeks post-delivery).

DATA EXTRACTION AND SYNTHESIS

Two authors independently selected and extracted data. Risk of bias was appraised using PROBAST (Prediction model Risk Of Bias ASsessment Tool). Data were synthesised without meta-analysis.

RESULTS

Seventeen studies, comprising 19 externally validated RAMs and 1 internally validated model, met the inclusion criteria. The most widely evaluated RAMs were the Royal College of Obstetricians and Gynaecologists guidelines (six studies), American College of Obstetricians and Gynecologists guidelines (two studies), Swedish Society of Obstetrics and Gynecology guidelines (two studies) and the Lyon score (two studies). In general, estimates of sensitivity and specificity were highly variable with sensitivity estimates ranging from 0% to 100% for RAMs that were applied to antepartum women to predict antepartum or postpartum VTE and 0% to 100% for RAMs applied postpartum to predict postpartum VTE. Specificity estimates were similarly diverse ranging from 28% to 98% and 5% to 100%, respectively.

CONCLUSIONS

Available data suggest that external validation studies have weak designs and limited generalisability, so estimates of prognostic accuracy are very uncertain.

PROSPERO REGISTRATION NUMBER

CRD42020221094.

Prophylactic Dose of Dalteparin in Pregnant Women With History of Venous Thromboembolisms and/or Thrombophilia: Real-World Data

Women with a history of venous thromboembolisms (VTEs) and/or thrombophilia are at increased risk of VTE during pregnancy. We analysed our cohort of such women who were treated with a prophylactic doses of dalteparin. 152 pregnant women with 179 pregnancies were classified into 3 groups: (1) previous VTE without thrombophilia (122 pregnancies); (2) previous VTE with thrombophilia (26 pregnancies) and (3) thrombophilia only (31 pregnancies). They were treated with prophylactic dalteparin in the prepartum and postpartum periods or only in the postpartum period. Occurrences of symptomatic VTE and bleeding episodes were followed, as well as dalteparin discontinuation and anti-Xa activity. Symptomatic deep vein thrombosis occurred in 4 women (2.2%) with 2 episodes in group 1 (in the postpartum period) and 2 episodes in group 2 (one in the prepartum and another in the postpartum period). Seven episodes (3.9%) of minor bleeding occurred. Dalteparin was not stopped in any women. Anti-Xa levels were within the prophylactic range. Our real-world data show a low incidence of thrombosis and minor bleeding in pregnant women treated with prophylactic dalteparin. The incidence of recurrent VTE was lower than that reported in women with similar risk, but without prophylactic anticoagulation.

Preventing Postpartum Venous Thromboembolism in 2022: A Narrative Review

The postpartum period represents the most critical time for pregnancy-associated venous thromboembolism (VTE), which is responsible for substantial morbidity and an important cause of maternal mortality. The estimated risk of postpartum VTE of about 1/1,000 deliveries can be modulated with the knowledge of maternal and obstetrical risk factors, although a precise estimate remains challenging in individuals. The use of postpartum low-dose low-molecular-weight heparins are tailored at intermediate and high-risk groups to reduce the thrombotic burden, despite the lack of dedicated randomized controlled trials. In this review, we will highlight the contemporary evidence on the risk of postpartum VTE, its stratification and its prevention. We will also discuss our knowledge on the values and preferences of women for postpartum thromboprophylaxis and their adherence to treatment.

Prevention and management of venous thromboembolism in pregnancy: cutting through the practice variation

There is clinical practice variation in the area of prevention and management of venous thromboembolism (VTE) in pregnancy. There are limited data and differing recommendations across major clinical practice guidelines, especially relating to the role of postpartum low-molecular-weight heparin (LMWH) for patients with mild inherited thrombophilia and those with pregnancy-related VTE risk factors. This chapter explores the issues of practice variation and related data for postpartum VTE prevention. Controversial topics of VTE management in pregnancy are also reviewed and include LMWH dosing and the role of anti-Xa level monitoring, as well as peripartum anticoagulation management around labor and delivery.

Approach to the Evaluation and Treatment of Venous Thromboembolism in Pregnancy

Thrombosis in pregnancy is a major cause of maternal and fetal morbidity and mortality. Risk stratification of venous thromboembolism (VTE) during pregnancy is complex. The hypercoagulability observed in pregnant women can reduce bleeding during childbirth, but may cause thrombosis especially in the presence of additional prothrombotic risk factors such as antiphospholipid antibodies or genetic thrombophilic defects. The availability of large datasets allows for the identification of additional independent risk factors, including assisted reproductive technologies (ARTs), endometriosis, and recurrent pregnancy loss. Data on the risk of VTE linked to COVID-19 in pregnant women are very limited, but suggest that infected pregnant women have an increased risk of VTE. Current guidelines on the prevention and treatment of VTE in pregnancy are based on available, albeit limited, data and mainly present expert opinion. Low-molecular-weight heparins (LMWHs) are the mainstay of anticoagulation to be employed during pregnancy. Administration of LMWH for VTE treatment in pregnancy should be based on the personalized approach, taking into account a weight-based adjusted scheme. During gestation, due to physiological changes, in women at high risk of VTE, monitoring of anti-Xa activity is performed to ensure adequate LMWH dosing. As for the treatment duration for pregnant women with acute VTE, guidelines suggest that anticoagulation should be continued for at least 6 weeks postpartum for a minimum total duration of therapy of 3 months.

External validation of a model to predict women most at risk of postpartum venous thromboembolism: Maternity clot risk

INTRODUCTION

Venous thromboembolism (VTE) is the leading cause of direct maternal mortality in high-income countries. We previously developed a risk prediction score for postpartum venous thromboembolism (VTE) in women without a previous VTE. In this paper, we provide further external validation and assess its performance across various groups of postpartum women from England.

MATERIALS AND METHODS

Cohort study using primary and secondary care data covering England. We used data from QResearch comprising women with pregnancies ending in live birth or stillbirth recoded in Hospital Episodes Statistics between 2004 and 2015. Outcome was VTE in the 6 weeks postpartum. Our predictor variables included sociodemographic and lifestyle characteristics, pre-existing comorbidities, and pregnancy and delivery characteristics.

RESULTS

Among 535,583 women with 700,185 deliveries, 549 VTE events were recorded (absolute risk of 7.8 VTE events per 10,000 deliveries). When we compared predicted probabilities of VTE for each woman from the original model with actual VTE events, we obtained a C-statistic of 0.67 (95% CI 0.65 to 0.70). However, our model slightly over-predicted VTE risk for the higher risk women (calibration slope = 0.84; 95% CI 0.74 to 0.94). Performance was similar across groups defined by calendar time, socioeconomic status, age group and geographical area. The score performed comparably with the existing algorithm used by the UK Royal College of Obstetrician and Gynaecologists.

CONCLUSIONS

Our model enables flexibility in setting new treatment thresholds. Adopting it in clinical practice may help optimise use of low-molecular-weight heparin postpartum to maximise health gain by better targeting of high-risk groups.

Uncaptured rates of postpartum venous thromboembolism: a US national analysis

OBJECTIVE

To quantify the proportion of postpartum venous thromboembolism (VTE) readmissions, including those that occur at different hospitals from index admission, and describe risk factors for this outcome.

DESIGN

Retrospective observational study.

SETTING

US hospitals included in the Nationwide Readmissions Database.

SAMPLE

A total of 3 719 238 patients >14 years of age with a delivery-associated hospitalisation in 2014.

METHODS

Univariate analysis was performed to identify patient and hospital factors associated with readmissions. Significant factors were included in multivariate logistic regression to identify independent risk factors. Results were weighted for national estimates.

MAIN OUTCOME MEASURES

Readmission with VTE to both index and different hospitals at 30, 60 and 90 days.

RESULTS

The VTE cumulative readmission rate was 0.053% (n = 1477), 0.063% (n = 1765) and 0.069% (n = 1938) at 30, 60 and 90 days, respectively. Patients were readmitted to different hospitals 31% of the time within 90 days. Risk factors for different hospital VTE readmission were unique and included younger age and initial admission to a small/medium-sized hospital. Initial admission to a for-profit hospital increased the likelihood of readmission to a different hospital.

CONCLUSIONS

Nearly one in three postpartum VTEs are missed by the current quality metrics, with significant implications for outcomes and quality. For-profit hospitals have a significant portion of their VTE readmissions hidden, falsely lowering their readmission rates relative to public hospitals.

TWEETABLE ABSTRACT

US analysis shows 1 in 3 readmissions for postpartum venous thromboembolism currently missed.