Using a population-based approach to prevent hepatocellular cancer in New South Wales, Australia: effects on health services utilisation

While the base case assumed a 25% program uptake, we also estimated the impact lower or higher recruitment would have on service utilisation. (See Table 3) Assuming a 10% program uptake, some additional 700 GP appointments and 300 specialist appointments would be required. This translates into 2 additional appointments for each GP and 10 extra appointments for each specialist per year. Assuming a 65% program uptake, approximately 4,500 more GP appointments and 2,000 more specialist appointments would be required in year 4. This translates into approximately 13 additional appointments per GP and 66 appointments per specialist per year.

Using a lower ALT cut-off level had the greatest impact on health service utilisation. Assuming that 90% of enrolees have ALT levels that require antiviral treatment (as compared to 50% in the base case), annual consultations per specialist would increase from 25.3 (at baseline) to 47.7. Assuming that 20% of participants have ALT levels requiring antiviral treatment would lead to a slight increase in GP services (from 5.0 at baseline to 5.5) and a significant reduction in the need for specialist services (from 25.3 to 9.1 per specialist) - see Table 3.

Using a lower cut-off for viral load level (2,000 IU/ml) for all enrolled patients, regardless of their age, leads to a slight reduction in the number of GP consultations (from 5.0 to 4.7 per GP), but a significant increase in specialist utilisation (from 25.3 to 32.0 per specialist).

Increasing the age at program enrolment from 35 to 40 years (age when guidelines suggests that HCC screening should commence) [23] reduces both the demand for GP services (from 5.0 at baseline to 3.8 visits per GP) and for specialist consultations (from 25.3 to 20.5 per specialist).

Sensitivity analyses on the risk reduction conferred by antiviral treatment on progression from CHB to cirrhosis, cirrhosis to liver failure and liver failure to death found that varying assumptions had practically no effect on the workload of GPs, specialists, and on the number of ultrasound examinations required (see Additional Files 1, 2, 3, 4 and 5).

In the absence of Australian HBV seroprevalence studies, we used CHB prevalence estimates based upon studies in Asian migrant populations in the UK, Canada and US [30]. In the absence of local data on participation rates in a hepatitis B screening and follow up program, we assumed similar participation rates for different migrant groups, although data from New Zealand suggest that significant differences exist with regards to CHB screening preferences by age and ethnicity [26].

As no consensus exists on ALT levels for treatment initiation, and as elevated ALT levels in patients with CHB may also be due to overweight or obesity (present in over 60% of Australian adults) [31], we estimated that approximately 50% of people with elevated viral loads also have elevated ALT levels. We used data derived from the REVEAL study to estimate the rate of malignant transformation by level of viral load [22], but acknowledge that factors such as viral genotypes, smoking, obesity, alcohol consumption and host genetic polymorphisms [32‐36] may also play an important role. The total number of specialist consultations is contingent upon the number of referrals, as well as the actual viral load and ALT levels present in the target population. In the absence of local data, these were inferred from other studies, or specialist opinion, so the numbers of episodes of care delivered may be at variance from the ones estimated by this paper.

Data collected through the B Positive project suggests that some local GPs have more than 100 patients with CHB in their practice records. We acknowledge that in areas with a large Asian-born population, a shortage in the number of local GPs and especially specialists would present significant challenges to program implementation. As approximately two thirds of GP practices are using practice management software programs that can support an electronic clinical decision making system, we are currently developing a GP desktop software module to facilitate patient recall and management; this would assist GPs to better manage the additional workload imposed by the B Positive program upon participating practices.

We assumed that most of the episodes of care take place in the public health sector, but have insufficient information on the current contribution of the private health sector to CHB management. As liver cancer is concentrated among populations of relative disadvantage, we assumed that the contribution of the private sector would be limited, but the validity of this assumption has not been tested. Additionally, equity implications of excluding the private sector from public health programs merit careful consideration. The mobilisation of private sector specialist resources could provide an expansion of specialist capacity in the short term, largely through the engagement of a wider pool of specialist gastroenterologists. Active involvement of government in contracting for services and/or staffing and in enabling community clinics to support their employment may facilitate private sector involvement, without shifting the financial burden to relatively disadvantaged patients and families.

In its 2005 report, the Australian Productivity Commission highlighted the need for an appropriate workforce in terms of structure and skills mix, to address current and emerging health care needs of Australians [37]. Under existing workforce arrangements, an increased capacity to manage CHB is conditional upon increasing the specialist workforce. This can be achieved through training additional specialists, overseas recruiting of doctors, or by using technology allowing the automation of some of the routine surveillance and follow up tasks. Creating shared decision support and review systems could provide a seamless transition from primary to specialist care, as dictated by changes in patients' disease states. In the future, we envisage that some of the components of the patient care pathway currently serviced by specialists (such as follow up of patients receiving antiviral medications) could be carried out in primary care, as is already the case for other blood borne infections, such as HIV and hepatitis C. Using practice nurses for CHB screening, outreach and follow up could provide additional resources to facilitate the follow up of low risk, routine CHB cases in primary care, but in the absence of data on their actual or projected numbers and the practice locations, it can only be hypothesised that this emerging segment of the workforce may have a significant future role in CHB surveillance and liver disease prevention.