Some of the problems encountered when updating a systematic review are outlined, with discussion of possible solutions. The major problems were: using a different reviewer; literature searching and sifting; study appraisal and lack of pre-determined 'acceptable' designs. The main lessons learned are that inclusion criteria may need to be revised, and that deviations from 'gold standard' systematic review methods should be documented. The paper concludes by noting that the updating of a systematic review is not straightforward, despite the application of recommended methodological safeguards. Yet, updating of systematic reviews is a process which will be undertaken increasingly, particularly by those involved in the development of evidence-linked clinical guidelines.
Centre for Reviews and Dissemination (1996) Undertaking Systematic Reviews of Research on Effectiveness. CRD Report 4. York: University of York .
3.
Cullum, N. (1997) Identification and analysis of randomized controlled trials in nursing: A preliminary study . Quality in Health Care6: 2-6 .
4.
Cullum, N. (1994) The Nursing Management of Leg Ulcers in the Community:A critical review of research. Liverpool: Department of Nursing, University of Liverpool .
5.
Goodman, C. (1993) Literature Searching and Evidence Interpretation for Assessing Health Care Practices. Stockholm: Swedish Council on Technology Assessment in Health Care (SBU ).
6.
Greenhalgh, T. (1997) Assessing the methodological quality of published papers . British Medical Journal315: 305-308 .
7.
Hayward, R. , Wilson, M. , Tunis, S.et al. (1995) Users' guides to the medical literature. VII. How to use clinical practice guidelines. A. Are the recommendations valid?Journal of the American Medical Association274: 7, 570-574 .
8.
MuIrow, C.D. , Linn, W.D. , Gaul, M.K. (1989) Assessing the quality of a diagnostic test evaluation . Journal of General Internal Medicine4: 288-295 .
9.
Moher, D. , Jadad, A.R. , Nicol, G.et al. (1995) Assessing the quality of RCTs: An annotated bibliography of scales and checklists . Controlled Clinical Trials16: 62-73 .
10.
Sackett, D.I. , Drummond, R. (1992) The science of the art of the clinical examination . Journal of the American Medical Association267:19, 2650-2652 .
11.
Sackett, D.L. , Haynes, R.B. , Guyatt, G.H.et al. (1991) Clinical Epidemiology -A basic science for clinical medicine. Boston: Little, Brown and Co.
12.
Schulz, K.F. , Chalmers, I. , Hayes, R.J.et al. (1995) Empirical evidence of bias: Dimensions of methodological quality associated with estimates of treatment effects in controlled trials . Journal of the American Medical Association273: 5, 408-412 .
13.
Sindhu, F , Dickson, R. (1997) Literature searching for systematic reviews . Nursing Standard11: 41, 40-42 .
