Prognosis of idiopathic membranous nephropathy: A methodologic meta-analysis

Abstract

Results in studies on prognosis and treatment of membranous nephropathy are conflicting. The aim of this investigation was to analyze the methodology of the existing research and to identify sources of these conflicting results. Studies published on prognosis of membranous nephropathy from 1970 to 1995 were identified using a Medline database literature search. The criteria for inclusion in the methodologic analysis were: (1) original article; (2) cohort study or clinical trial with > or = 50 adults; (3) zero time near the diagnostic renal biopsy; and (4) follow-up > or = six months. Ten well-accepted methodologic standards for prognostic research were applied to each study and the compliance was evaluated. Among the 26 studies that met the inclusion criteria, the median number of standards fulfilled was 4 and the highest was 7. The proportion of studies adhering to the individual standards was: (1) adequate diagnostic criteria, 35%; (2) definite end point, 46%; (3) adequate analysis of a surrogate end point, 52%; (4) analysis of baseline severity, 0%; (5) indication of baseline frequency for candidate predictors, 35%; (6) reproducible classification of predictors, 85%; (7) multivariable analysis, 50%; (8) identification of the variables' importance in multivariable analysis, 38%; (9) evaluation of the effect of treatment on predictors, 19%; and (10) adequate analysis of censored patients, 58%. We conclude that basic methodologic principles have frequently been disregarded. The consideration of these standards in future research can improve the interpretability and applicability of results and help reconcile conflict when results are compared among different studies.

Prognostic significance of glomerular and tubulointerstitial morphometry in idiopathic membranous nephropathy

“…The reason for this is most probably due to a great variation in inclusion criteria and in the outcomes evaluated, as stipulated by Marx et al [15]. Consequently, there is a large diversity in the results of the prognostic factors studied, so that for virtually every prognostic factor investigated, there are studies demonstrating or refuting its significance in IMN [15,25]. This study attempted to overcome some shortcomings of previous studies by focusing on glomerular and tubulointerstitial morphometric variables in a well-defined cohort of patients with IMN.…”

“…This study attempted to overcome some shortcomings of previous studies by focusing on glomerular and tubulointerstitial morphometric variables in a well-defined cohort of patients with IMN. Our outcome was defined as proposed by Marx et al [15].…”

Reporting of prognostic studies of tumour markers: a review of published articles in relation to REMARK guidelines

“…These have been investigated in previous research in other areas of prognosis, including systematic reviews of individual diseases or tumour markers, and have also found evidence or discuss poor reporting of followup time (Marx and Marx, 1997;Malats et al, 2005;Altman, 2007); loss of follow-up (Infante-Rivard et al, 1989;Burton and Altman, 2004;Altman, 2007); study dates (Altman, 2007); effect estimates and confidence intervals for univariable and multivariable analyses (Riley et al, 2003;Scholten-Peeters et al, 2003;Barth et al, 2004;Kuijpers et al, 2004;Malats et al, 2005); definitions of outcomes of overall survival and disease-free survival (Altman et al, 1995;Malats et al, 2005;Hudis et al, 2007;Kyzas et al, 2007b); and heterogeneity of patient and patient treatments (Pfisterer et al, 1994;Gasparini, 1998;Sauerbrei, 2005).…”

Systematic Reviews of Evaluations of Prognostic Variables

“…The table shows a list of those relating to internal validity, which draws on previous suggestions. [9][10][11][12][13] A reliable prognostic study requires a well defined cohort of patients at the same stage of their disease. Some authors suggest that the sample should be an "inception" cohort of patients early in the course of the disease (perhaps at diagnosis).…”

“…For example, a review of prognosis of idiopathic membranous nephropathy included two questions on the nature of the end points, reflecting particular problems in a discipline where many studies used ill defined surrogate end points. 13 In addition to internal validity some checklists consider aspects of external validity and clinical usefulness of studies. Notably, Laupacis et al included five questions relating to the clinical usefulness of a study.…”