Hill et al.  compared the costs of urine electrophoretic tests with sFLC immunoassays in routine screening. On a per-patient basis, costs increased by £4.73 if sFLC tests were used. However, this figure compared sFLC analysis in 100% of the patients with urine analysis in only 40% (due to poor compliance). Furthermore, savings made due to the reduction of time spent interpreting urine electrophoresis gels were unquantified and the authors concluded in favour of sFLC analysis, as better clinical governance was achieved with more clinical diagnoses. Potential organisational benefits, through replacing urine electrophoresis with sFLC assays, were also identified at the Christie Hospital, Manchester, UK; this study considered monitoring as well as screening and the data is presented in Section 24.10. The combination of CZE plus sFLC (e.g. Bakshi et al. , Holding et al. , Vermeersch et al. ) gives the opportunity of a more automated screening procedure, and may further reduce operating costs.
Katzmann et al.  compared the costs of sFLC screening with urine testing in the USA. The 2006 Medicare reimbursement for sFLCs was $38 compared with $71 for urine assays (total protein, UPE and uIFE). As sFLC tests cost approximately half that of urine tests, considerable laboratory savings could be made. Zia & Singh  reviewed testing patterns from an inner-city hospital in Midwestern USA (2009-2012) and found that costs could be reduced in spite of increased sFLC testing by more selective use of sIFE and UPEP/uIFE analysis.
Direct assessments of clinical cost benefits are difficult to make. However, one relatively simple clinical situation that may benefit by measuring sFLCs is the determination of underlying pathology in patients presenting with acute kidney injury (Chapter 27). If MM is suspected, the normal procedure has been to perform SPE/IFE and UPE. A simpler and better approach would be to perform SPE and sFLCs, which provides a rapid screen for monoclonal disease. Early diagnosis is essential in these patients and would allow the prompt initiation of disease-specific treatment and prevent irreversible renal damage and the need for long-term dialysis . Data from a health economics study of this particular diagnostic issue has now been published by Cook et al.  who reported that there were economic gains (for the use of SPE + Freelite®) at both diagnostic and treatment stages. The use of sFLC analysis reduced the time to diagnosis and treatment and thereby improved the probability of both renal recovery and survival.