Abstract
Objective
To assess how different imputation methods used to account for missing variance data
in primary studies influence tests of heterogeneity and pooled results from a meta-analysis
with continuous outcomes.
Study Design and Setting
Point and variance estimates for changes in serum creatinine, glomerular filtration
rate, systolic blood pressure, and diastolic blood pressure were variably reported
among 48 primary longitudinal studies of living kidney donors (71%–78% of point estimates
were reported, 8%–13% of variance data were reported). We compared the results of
meta-analysis, which either were restricted to available data or used four methods
to impute missing variance data. These methods used reported P-values, reported nonparametric summaries, results from other similar studies using
multiple imputation, or results from estimated correlation coefficients.
Results
Significant heterogeneity was present in all four outcomes regardless of the imputation
methods applied. The random effects point estimates and 95% confidence intervals varied
little across imputation methods, and the differences were not clinically significant.
Conclusions
Different methods to impute the variance data in the primary studies did not alter
the conclusions from this meta-analysis of continuous outcomes. Such reproducibility
increases confidence in the results. However, as with most meta-analyses, there was
no gold standard of truth, and results must be interpreted judiciously. The generalization
of these findings to other meta-analyses, which differ in outcomes, missing data,
or between-study heterogeneity, requires further consideration.
Keywords
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to Journal of Clinical EpidemiologyAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- Beyond classical meta-analysis: can inadequately reported studies be included?.Drug Discov Today. 2004; 9: 924-931
- On variability of effects for a metaanalysis of rheumatoid arthritis radiographic progression.J Rheumatol. 2000; 27: 540-542
- Variance imputation for overviews of clinical trials with continuous response.J Clin Epidemiol. 1992; 45: 769-773
- Quantitative methods in the review of epidemiologic literature.Epidemiol Rev. 1987; 9: 1-30
- A systematic review identifies a lack of standardization in methods for handling missing variance data.J Clin Epidemiol. 2006; 59: 342-353
- 20 years or more of follow-up of living kidney donors.Lancet. 1992; 340: 807-810
- The living donor in kidney transplantation.Ann Intern Med. 1987; 106: 719-727
- Complications and risks of living donor nephrectomy.Transplantation. 1997; 64: 1124-1128
- Meta-analysis: Risk for hypertension in living kidney donors.Ann Intern Med. 2006; 145: 185-196
- Older living donors provide excellent quality kidneys: a single center experience (older living donors).Clin Transplant. 2005; 19: 600-606
- Early systemic and renal responses to nephrectomy in normotensive kidney donors.Nephrol Dial Transplant. 1993; 8: 448-453
- Long-term follow-up of the remaining kidney in living related kidney donors.Int Urol Nephrol. 1989; 21: 547-553
- The effect of uninephrectomy on mineral metabolism in normal human kidney donors.Am J Kidney Dis. 1988; 11: 393-401
- The 10 years single center experience of using elderly donors for living related kidney transplantation.Geriatr Nephrol Urol. 1997; 7: 127-130
- Analysis of donor selection procedure in 139 living-related kidney donors and follow-up results for donors and recipients.Nephrol Dial Transplant. 1994; 9: 163-168
- Renal transplant from living donor. Experience of the Parma Center.Minerva Urol Nefrol. 1998; 50 ([in Italian]): 121-125
- Renal function after nephrectomy in renal donors.Tokai J Exp Clin Med. 1982; 7: 511-516
- Living kidney donor follow-up in a dedicated clinic.Transplantation. 2005; 79: 1247-1251
- Experience with living related donor nephrectomy: evaluation of 200 cases.Ann Saudi Med. 1993; 13: 416-419
- Kidney function and compensatory growth of the kidney in living kidney donors.Scand J Urol Nephrol. 1976; 10: 134-136
- Risks and complications in 160 living kidney donors who underwent nephroureterectomy.Nephrol Dial Transplant. 2003; 18: 2648-2654
- The effect of kidney donation on total renal function.Transplant Proc. 1995; 27: 2592
- Functional compensation of kidney function in recipients and donors after transplantation between related subjects.Scand J Urol Nephrol. 1973; 7: 200-204
- The impact of renal donation: long-term follow-up of living donors in a single center in Mexico.Transplant Proc. 1987; 19: 1500-1502
- Long-term renal, endocrine, and hematologic evaluation of kidney donors.Transplant Proc. 1989; 21: 1946-1948
- Compensatory hyperfunction in living kidney donors.Nephrologie. 2002; 23 ([in French]): 173-177
- Living related kidney donors. A 14-year experience.Ann Surg. 1986; 203: 637-643
- Pair-tested renal reserve filtration capacity in kidney recipients and their donors.J Am Soc Nephrol. 1994; 4: 1798-1808
- Renal function after nephrectomy for donor organs.S Afr Med J. 1986; 69: 177-179
- Are black living-related renal donors at greater long-term risk of renal complications than white donors?.Transplant Proc. 1991; 23: 1328-1329
- Impact of renal donation. Long-term clinical and biochemical follow-up of living donors in a single center.Am J Med. 1985; 79: 201-208
- Response to acute protein load in kidney donors and in apparently normal postacute glomerulonephritis patients: evidence for glomerular hyperfiltration.Lancet. 1985; 2: 461
- Long-term follow-up of related kidney donors after nephrectomy.Lijec Vjesn. 1992; 114 ([in Serbo-Croatian (Roman)]): 110-112
- Living donors in renal transplantation: a long-term study.Transplant Proc. 1987; 19: 1498-1499
- Long-term follow-up of living related donors at a single center in Taiwan.Transplant Proc. 1992; 24: 1440-1441
- Long-term evaluation of kidney donors.Transplant Proc. 1996; 28: 93-94
- Kidney transplantation with living donors: nine years of follow-up of 628 living donors.Transplant Proc. 2003; 35: 946-947
- Optimizing open live-donor nephrectomy—long-term donor outcome.Clin Transplant. 2004; 18: 301-305
- Living donor nephrectomy: a 28-year experience at Heidelberg University.Transplant Proc. 1997; 29: 2769
- Evaluation of the state of health of living related kidney transplantation donors.Transpl Int. 1998; 11: S57-S59
- Long-term follow-up of 102 living kidney donors.Clin Nephrol. 1998; 50: 232-235
- Long-term follow-up of renal donors.Transplant Proc. 1998; 30: 2283-2285
- Long-term blood pressure and renal function in kidney donors.Kidney Int. 1986; 29: 1072-1076
- Assessment of long-term risks for living related kidney donors by 24-h blood pressure monitoring and testing for microalbuminuria.Clin Transplant. 1997; 11: 415-419
- No evidence of accelerated loss of kidney function in living kidney donors: results from a cross-sectional follow-up.Transplantation. 2001; 72: 444-449
- Long-term renal function in kidney donors: a comparison of donors and their siblings.Ann Intern Med. 1986; 105: 1-8
- Microalbuminuria and hypertension in long-term renal donors.Transplantation. 1988; 45: 59-65
- The health of living kidney donors 20 years after donation.Transplant Proc. 2001; 33: 2041-2042
- Renal outcome 25 years after donor nephrectomy.J Urol. 2001; 166: 2043-2047
- Renal function in unilateral nephrectomy subjects.J Urol. 1992; 147: 337-339
- Long-term follow-up of kidney donors: a longitudinal study.Nephrol Dial Transplant. 1997; 12: 1615-1621
- Living kidney donor transplantation—new dimensions.Transpl Int. 1998; 11: S50-S56
- Experience with 247 living related donor nephrectomy cases at a single institution in Japan.Jpn J Surg. 1988; 18: 252-258
- Renal function and glomerular permselectivity late after living related donor transplantation.Transplantation. 1996; 62: 47-51
- Establishing a transplant coordinator-led living kidney donor follow-up clinic.Prog Transplant. 2003; 13: 138-141
- Glomerular filtration rate, hypertension and proteinuria after renal ablation: a long-term follow-up study in kidney donors.Scand J Urol Nephrol Suppl. 1988; 108: 49-55
- Multiple imputation: a primer.Stat Methods Med Res. 1999; 8: 3-15
Deeks JJ, Higgins JPT, Altman DG, editors. Analysing and presenting results. In: Higgins JPT, Green S, editors. Cochrane handbook for systematic reviews of interventions 4.2.5 [updated May 2005]: section 8. In: the Cochrane library, Issue 3, 2005. Chichester, UK: John Wiley & Sons, Ltd.; 2005.
- A meta-analysis of the effects of dietary protein restriction on the rate of decline in renal function.Am J Kidney Dis. 1998; 31: 954-961
- Quantifying heterogeneity in a meta-analysis.Stat Med. 2002; 21: 1539-1558
- Meta-analysis in clinical trials.Control Clin Trials. 1986; 7: 177-188
- Some statistical methods for combining experimental results.Int J Technol Assess Health Care. 1990; 6: 5-30
- Advanced methods in meta-analysis: multivariate approach and meta-regression.Stat Med. 2002; 21: 589-624
Article info
Publication history
Published online: October 25, 2006
Accepted:
June 2,
2006
Identification
Copyright
© 2007 Elsevier Inc. Published by Elsevier Inc. All rights reserved.