Venous thromboembolism prophylaxis in the United States: still room for improvement

Incidences and variations of hospital acquired venous thromboembolism in Australian hospitals: a population-based study

BACKGROUND

Data on hospital-acquired venous thromboembolism (HA-VTE) incidence, case fatality rate and variation amongst patient groups and health providers is lacking. We aim to explore HA-VTE incidences, associated mortality, trends and variations across all acute hospitals in New South Wales (NSW)-Australia.

METHODS

A population-based study using all admitted patients (aged 18-90 with a length of stay of at least two days and not transferred to another acute care facility) in 104 NSW acute public and private hospitals during 2002-2009. Poisson mixed models were used to derive adjusted rate ratios (IRR) in presence of patient and hospital characteristics.

RESULTS

Amongst, 3,331,677 patients, the incidence of HA-VTE was 11.45 per 1000 patients and one in ten who developed HA-VTE died in hospital. HA-VTE incidence, initially rose, but subsequently declined, whereas case fatality rate consistently declined by 22 % over the study period. Surgical patients were 128 % (IRR = 2.28, 95 % CI: 2.19-2.38) more likely to develop HA-VTE, but had similar case fatality rates compared to medical patients. Private hospitals, in comparison to public hospitals had a higher incidence of HA-VTE (IRR = 1.76; 95 % CI: 1.42-2.18) for medical patients. However, they had a similar incidence (IRR = 0.91; 95 % CI: 0.75-1.11), but a lower mortality (IRR = 0.59; 95 % CI: 0.47-0.75) amongst surgical patients. Smaller public hospitals had a lower HA-VTE incidence rate compared to larger hospitals (IRR < 0.68) but a higher case fatality rate (IRR > 1.71). Hospitals with a lower reported HA-VTE incidence tended to have a higher HA-VTE case fatality rate.

CONCLUSION

Despite the decline in HA-VTE incidence and case fatality, there were large variations in incidents between medical and surgical patients, public and private hospitals, and different hospital groups. The causes of such differences warrant further investigation and may provide potential for targeted interventions and quality improvement initiatives.

Rate of venous thromboembolism among surgical patients in Australian hospitals: a multicentre retrospective cohort study

OBJECTIVES

Despite the burden of venous thromboembolism (VTE) among surgical patients on health systems in Australia, data on VTE incidence and its variation within Australia are lacking. We aim to explore VTE and subsequent mortality rates, trends and variations across Australian acute public hospitals.

SETTING

A large retrospective cohort study using all elective surgical patients in 82 acute public hospitals during 2002-2009 in New South Wales, Australia.

PARTICIPANTS

Patients underwent elective surgery within 2 days of admission, aged between 18 and 90 years, and who were not transferred to another acute care facility; 4 362 624 patients were included.

OUTCOME MEASURES

VTE incidents were identified by secondary diagnostic codes. Poisson mixed models were used to derive adjusted incidence rates and rate ratios (IRR).

RESULTS

2/1000 patients developed postoperative VTE. VTE increased by 30% (IRR=1.30, CI 1.19 to 1.42) over the study period. Differences in the VTE rates, trends between hospital peer groups and between hospitals with the highest and those with the lowest rates were significant (between-hospital variation). Smaller hospitals, accommodated in two peer groups, had the lowest overall VTE rates (IRR=0.56:0.33 to 0.95; IRR=0.37:0.23 to 0.61) and exhibited a greater increase (64% and 237% vs 19%) overtime and greater between-hospital variations compared to larger hospitals (IRR=8.64:6.23 to 11.98; IRR=8.92:5.49 to 14.49 vs IRR=3.70:3.32 to 4.12). Mortality among patients with postoperative VTE was 8% and remained stable overtime. No differences in post-VTE death rates and trends were seen between hospital groups; however, larger hospitals exhibited less between-hospital variations (IRR=1.78:1.30 to 2.44) compared to small hospitals (IRR>23). Hospitals performed differently in prevention versus treatment of postoperative VTE.

CONCLUSIONS

VTE incidence is increasing and there is large variation between-hospital and within-hospital peer groups suggesting a varied compliance with VTE preventative strategies and the potential for targeted interventions and quality improvement opportunities.

Experimental Validation of Methods for Prophylaxis against Deep Venous Thrombosis: A Review and Proposal

The experimental procedure by which the valve cusp hypoxia (VCH) hypothesis of the etiology of deep venous thrombosis (DVT) was confirmed lends itself to testing of methods of prophylaxis. Similar animal experiments could end the present exclusive reliance on statistical analysis of data from large patient cohorts to evaluate prophylactic regimes. The reduction of need for such (usually retrospective) analyses could enable rationally-based clinical trials of prophylactic methods to be conducted more rapidly, and the success of such trials would lead to decreased incidences of DVT-related mortality and morbidity. This paper reviews the VCH hypothesis ("VCH thesis", following its corroboration) and its implications for understanding DVT and its sequelae, and outlines the experimental protocol for testing prophylactic methods. The advantages and limitations of the protocol are briefly discussed.

Changing practice: implementation of a venous thromboembolism prophylaxis protocol at an academic medical center

BACKGROUND

The Institute of Medicine has identified a "quality chasm" between existing evidence and actual clinical practice. The Venous Thromboembolism Prevention Study has shown that enoxaparin prophylaxis is a safe and effective way of preventing postoperative venous thromboembolism. This article presents a "how-to" guide for implementation of a venous thromboembolism prophylaxis protocol.

METHODS

The Venous Thromboembolism Prevention Study prophylaxis protocol included provision of postoperative, prophylactic dose enoxaparin for the duration of inpatient stay. Compliance was considered at the individual patient level and defined as appropriate provision of protocol-appropriate enoxaparin prophylaxis. Multiple simultaneous interventions to improve protocol compliance were undertaken. Both physician and physician assistant "champions" were identified. Interventions included staff and surgeon educational sessions, discussion of venous thromboembolism-themed articles at journal club, and monthly e-mail reminders specific to the protocol, among others. Compliance rates over time were compared using the chi-square test.

RESULTS

The authors reviewed medical records from 945 consecutive admissions to the plastic surgery service who met Venous Thromboembolism Prevention Study eligibility criteria over a 30-month period. Initial education sessions significantly increased compliance over baseline (55 percent versus 10 percent; p<0.001). After formal protocol adoption, compliance increased steadily over the first 9 months and peaked by 1 year. In the absence of any direct intervention, compliance remained stable at 90 percent for the final 12 months of the study. This was significantly increased when compared with the period of time immediately following protocol adoption (90 percent versus 77 percent; p<0.001).

CONCLUSION

This article provides readers with a practical approach for implementation of a venous thromboembolism prophylaxis protocol at their hospital.

Clinicians adopting evidence based guidelines: a case study with thromboprophylaxis

Background

Venous Thromboembolism (VTE) is a cause of hospital mortality and managing its morbidity is associated with significant expenditure. Uptake of evidenced based guideline recommendations intended to prevent VTE in hospital settings is sub-optimal. This study was conducted to explore clinicians' attitudes and the clinical environment in which they work to understand their reluctance to adopt VTE prophylaxis guidelines.

Methods

Between February and November 2009, 40 hospital employed doctors from 2 Australian metropolitan hospitals were interviewed in depth. Qualitative data were analysed according to thematic methodology.

Results

Analysis of interviews revealed that barriers to evidence based practice include i) the fragmented system of care delivery where multiple members of teams and multiple teams are responsible for each patient's care, and in the case of VTE, where everyone shares responsibility and no-one in particular is responsible; ii) the culture of practice where team practice is tailored to that of the team head, and where medicine is considered an 'art' in which guidelines should be adapted to each patient rather than applied universally. Interviewees recommend clear allocation of responsibility and reminders to counteract VTE risk assessment being overlooked.

Conclusions

Senior clinicians are the key enablers for practice change. They will need to be convinced that guideline compliance adds value to their patient care. Then with the support of systems in the organisation designed to minimize the effects of care fragmentation, they will drive practice changes in their teams. We believe that evidence based practice is only possible with a coordinated program that addresses individual, cultural and organisational constraints.