One of the challenges for an economic feasibility study examining the SBN role is to identify the immediate and final effects of the role on outcomes. As discussed above, much of the immediate impact of the model is on the process of health service delivery. SBNs’ work has the potential to influence health service utilisation within the hospital-based breast clinic, in acute care services within the hospital itself, and in home and community services. This project provided an opportunity to observe SBNs in their work and to assess the immediate implications of the model of care on the utilisation of existing health service resources.
Designing an observational study such as this produces a number of challenges. These include:
• the need for controls, so that valid comparisons can be made between services with and without SBNs;
• meeting the concerns of teams and institutions regarding observation; and
C h a p t e r 9 : E v a l u a t i n g t h e e c o n o m i c f e a s i b i l i t y o f t h e s p e c i a l i s t b r e a s t n u r s e r o l e
• ensuring a balance is achieved in terms of protecting the ethical concerns of those being observed (eg balancing the ethics of
withdrawing the SBN service for observational purposes with the need to justify the development of the SBN model of care).
Within the demonstration project, the opportunities to conduct such an
observational study were limited. The most readily observable arena in which the SBN may affect resource utilisation was an outpatients’ clinic. For this reason a breast clinic was selected as an illustrative case study. The methods applied in this case study could be used in future economic evaluation studies in this area.
The breast clinic at the Women's Health Centre, Royal Adelaide Hospital agreed to participate in the observational study. This clinic has a long established position similar in many respects to the evidence-based SBN model of care, and it was felt that an evaluation of that role, including economic evaluation, was important. The protocol for the observational study involved three steps:
1 identifying the resource inputs to the breast clinic;
2 observing the operation of the breast clinic and measuring the resources consumed in the absence of the SBN (the “without SBN” scenario); and
3 observing the operation of the clinic and measuring the resources consumed with the SBN present (the “with SBN” scenario).
The difference in resource utilisation between the “without SBN” and “with SBN” observations approximates the incremental effect of the SBN on resource
utilisation within the clinic. The direction of any change in costs requires careful examination. An increase in costs may mean that previously unmet needs are being met as a result of the SBN intervention. Alternatively, a decrease in costs could indicate potential efficiencies to be gained from SBNs. In this case study, differences in resource utilisation occurred in the way in which resources were deployed, rather than in the total quantity of resources consumed. In this case, attaching dollar values to the measurement of resources adds nothing to the results. Therefore, the cost analysis focuses on changes to the mix of resource inputs into the breast clinic.
An initial visit was made to the Adelaide breast clinic in February 1998, in order to observe its functioning and identify the resources consumed in the care of women with breast cancer. A detailed description of the clinic is provided below.
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The output of this initial observation was used to generate a data recording sheet for the “without SBN” and “with SBN” observations. The data sheets recorded the amount of staff input (hours worked) into the clinic (by occupational category) and documented the specific resource inputs for each patient seen at the clinic. The primary aim of the observation study was to record the amount of time spent by clinical staff with breast cancer patients participating in the SBN project. In this way, any changes in the composition of clinical staff and the amount of time spent with women during consultations due to the presence or absence of the SBN could be measured.
To achieve this aim, a taxonomy of patient type was developed to direct research towards those women participating in the demonstration project. Given that the observer (the data manager for the breast clinic) could not observe more than one consultation simultaneously, this provided a practical method for classifying patients. A minimum amount of information was recorded for all breast clinic patients (such as which staff were involved in the clinical consultation, and any diagnostic procedures performed). Additional information, such as the duration of the consultation and the attitudes of other staff members to the absence or presence of the SBN, was collected for those women recruited into the SBN project (Type A patients).
The taxonomy of patient type was as follows:
Type A = New patients – women who have symptoms indicative of a malignancy, and who may require surgical intervention.
Type B = New patients – women who have symptoms not indicative of a malignancy, and who are managed conservatively.
Type C = Former clinic patients – women undergoing further diagnostic assessment and surveillance (this may include a small number of post-operative patients). Only patients who would have been seen by the SBN as part of routine follow-up have been included in this category.
Type D = Patients referred for breast reconstruction, breast reduction or the replacement of breast implants (given medical indication).
Type F = Other
Additional information was sought from the clinical staff for each clinical consultation, via a short questionnaire. This was in order to assess the attitudes
C h a p t e r 9 : E v a l u a t i n g t h e e c o n o m i c f e a s i b i l i t y o f t h e s p e c i a l i s t b r e a s t n u r s e r o l e of the clinical staff to the presence or absence of the SBN, the impact this had on their interaction with the women, and the duration of the consultation (Appendix 61).
The “without SBN” assessment involved observation and data collection over four days (12, 16, 19 and 23 March 1998). The “with SBN” phase of the study was conducted in a series of two stages. Stage 1 involved observation and data
collection over four days (29 June, 2, 6 and 9 July 1998) and this was repeated over another four days (20, 23, 27 and 30 July 1998).