Venous thromboembolism (VTE), which comprises deep vein thrombosis (DVT) and pulmonary embolism (PE) represents a major public health problem. VTE is primarily a problem in hospitalized or recently hospitalized patients. The incidence of VTE has been shown to be more than 100 times greater among hospitalized patients than those in the community. In Australia, VTE is estimated to complicate 2-3 per 1000 hospital admissions, but varies widely by principle diagnosis. Moreover, postmortem studies indicate that approximately 10% of all hospital deaths are attributed to PE,[3–5] making it the most common preventable cause of hospital death.
In recent years, the prevention of VTE has been identified nationally and internationally as a priority area for improving patient safety. To support these efforts, a number of evidence-based guidelines have been made available which outline the appropriate use of prophylaxis to prevent VTE in a variety of patient populations [7–13]. Patients should be treated according to their individual risk and associated clinical conditions [7, 11, 14]. The Australian and New Zealand Working Party on the Management and Prevention of Venous Thromboembolism (ANZ-WP), which first convened in 1997, has sought to provide a practical pocket-sized booklet that summarised current best practice in VTE prevention. The most recently published version of these recommendations is based on guidelines from the International Union of Angiology and the American College of Chest Physicians (ACCP) and state that every hospitalized adult patient should be assessed for their risk of VTE.
Despite the commonly held perception that VTE is a complication of major surgery, postmortem studies have shown that approximately 70% of fatal PEs occur in non-surgical patients[3–5]. Further, it is accepted in the literature that 50-70% of symptomatic thromboembolic events occur in non-surgical patients[7, 14]. Nevertheless, the evidence base for clinical decision making regarding thromboprophylaxis in medical patients remains limited. Data from two meta-analyses demonstrate relative risk reductions of between 38% and 57% with the use of pharmacological prophylaxis depending on the endpoint being assessed[16, 17]. These data have recently been corroborated by the National Health and Medical Research Council of Australia, who present relative risk reductions of between 39% and 60% with the use of pharmacological prophylaxis in general medical patients admitted to hospital.
Available published data from multinational observational studies demonstrate the underuse or suboptimal use of VTE prophylaxis to be a global problem. In the IMPROVE (International Medical Prevention Registry on Venous Thromboembolism) study, which assessed routine clinical practices in the provision of VTE prophylaxis in acutely ill hospitalized medical patients from 52 hospitals in 12 countries, only 60% of patients who met the criteria for prophylaxis actually received it . The global ENDORSE (Epidemiologic International Day for the Evaluation of Patients at Risk for Venous Thromboembolism in the Acute Hospital Care Setting) study evaluated over 68,000 patients in 365 hospitals across 32 countries, again showing that amongst the surgical patients at risk only 58.5% received ACCP-recommended VTE prophylaxis whilst this was even lower (39.5%) amongst at-risk medical patients . Further analysis of the ENDORSE study data has shown that whilst the use of prophylaxis differs between countries, in general its use appears to be associated with disease severity rather than medical diagnosis .
This global picture also extends to Australia. A study of 250 surgical patients at the Royal Hobart Hospital, Tasmania, found that only 59.2% of patients had received appropriate prophylaxis according to the hospital's approved guidelines . Amongst patients at high risk of VTE, only 25.7% were prescribed the recommended preventive measures. Similarly, in 2002 it was reported that the majority of inpatients in The Canberra Hospital (TCH) were not receiving appropriate prophylaxis according to international guidelines [22, 23]. More recently, in the ENDORSE study, 80% of surgical patients were at risk for VTE yet only 72% received ACCP-recommended treatment. Consistent with global trends medical patients again fared worse with only 42% of those at risk receiving ACCP-recommended treatment .
There is a clear need for improved implementation of existing guidelines. Various strategies have been employed and their effectiveness systematically reviewed [24, 25]. Passive dissemination of guidelines was found to be the least effective method whilst the most effective strategies combined a system of active education of health providers, the use of reminders to assess for VTE risk and iterative audit and feedback to enable a continuous cycle of quality improvement. When such a process was employed at the Royal Hobart Hospital, Tasmania, a significant increase in adherence to guidelines resulted, the biggest improvement being amongst patients at high-risk (from 25.7% pre-intervention to 76.5% post-intervention) . Similarly, data collected in TCH over the period 2001-2005 as part of a quality improvement program highlighted that, at baseline, there was a clear absence of policies to assess and respond to patient risk. This improved over the duration of the study; there was a statistically significant increase in the use of risk assessment in the ward setting (from 7.7% to 100%) and in the extent of coverage of patients with anticoagulant prophylaxis (from 48% to 74%).
In this paper we report the results of a multicentre clinical audit study examining the effect of a dedicated VTE nurse educator on the use of prophylactic measures in acutely ill medical patients at 15 hospitals across Australia. The specific aims of the audit were to determine the extent to which appropriate VTE prophylaxis is being utilized at baseline and to examine the impact of a multifaceted program on the rate of appropriate VTE prophylaxis.