Department of Internal Medicine Mayo Clinic Rochester, Minnesota, USA
Sir,
Nephrologists are increasingly challenged to make treatment decisions on their patients, based on current evidence. Dr Adu's [1] recent editorial on treatment options for lupus nephritis informs us of numerous challenges encountered by physicians when dealing with treatment options for lupus nephritis which have variable efficacy. These challenges could be categorized into (a) challenges in interpreting the current medical information on lupus nephritis and (b) challenges in communicating results of studies and adverse effects to patients.
Among the challenges in interpreting the current medical information on lupus nephritis, is the physician's preparedness to understand the clinical significance of published articles. Using guidelines for levels of evidence for articles on therapy [2], it is obvious that there are very few systematic reviews on lupus nephritis [3] (Level 1c), and none would qualify for Level 1a (systemic reviews of large randomized controlled trial). The results of the randomized trial on mycophenolate mofetil (MMF) [4] were limited by small numbers of patients, the study was not double blinded and had insufficient power to show additional benefit of MMF. Though it is tempting to generalize the information and treat all patients with lupus nephritis with MMF based on the information of diminished side-effect profile presented in this study [4], one should wait for a larger multi-centric double-blinded trial to address the issues of confounders and eliminate bias. Using the data presented by Bansal et al. [3], therapies comparing prednisone alone with prednisone+immunosuppressive agents, the number needed to treat (NNT) was 8 for ESRD and mortality (absolute risk reduction, 13.2% and 12.9% respectively; NNT is the reciprocal of absolute risk reduction). These results were based on the systemic review of 440 patients from 19 trials and should be carefully weighed against the results of 42 patients on MMF [4].
Communication of treatment results to patients present additional challenges to the physician. An expert's perception of risk is based on the likelihood of risk and potential outcome of risk, such as disease, injury and death. Patients, however, evaluate risk as a combination of likelihoodxoutcomexoutrage factors [5]. Outrage factors are determined by the perceived severity and resulting public outrage for particular risks. Outrage factors are made up of less risk vs high risk elements, including factors like familiarity vs unfamiliarity, natural vs unnatural, visible benefits vs no visible benefits, ethically neutral vs unethical and voluntary situations vs involuntary ones. Side-effects of drugs with characteristics on the less risky side are perceived as less severe and provoke less outrage than other similar side effects with characteristics of a more risky side.
Additionally, the way physicians present risks to their patients (relative risk vs absolute risk) may misguide the patient in selecting one therapy over another, equally efficacious therapy. Alternative methods of presenting adverse effects of medications, as Number needed to Harm [6], have been suggested, but clinical data on patients' understanding of these terms is unclear. Physicians need to communicate the limitations of current evidence to the patients and incorporate patient preferences while making decisions for individual patients.
Routine incorporation of critical appraisal of articles in the curriculum of nephrology fellowship programmes and application of principles of evidence-based medicine could improve the physicians' ability to understand medical literature and communicate evidence-based recommendations to their patients [7,8].
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