The Problem of Mathematical Coupling: How can Statistical Artifact and Biological Causation be Separated When Relating Protein Intake to Clearance in ‘Predialysis’ and Dialysis Patients?
Restricted accessResearch articleFirst published online September, 1997
The Problem of Mathematical Coupling: How can Statistical Artifact and Biological Causation be Separated When Relating Protein Intake to Clearance in ‘Predialysis’ and Dialysis Patients?
MehrotraR., SaranR., MooreH.L.Toward targets for initiation of chronic dialysis.Perit Dial Int1997; 17: 497–508.
2.
McCusterF.X., TeehanB.P., ThorpeK.E., KeshaviahP.R., ChurchillD.N.For the Canada-USA Peritoneal Dialysis Group. How much peritoneal dialysis is required for the maintenance of a good nutritional state?Kidney Int1996; 50(Suppl 56): S56–61.
3.
LowrieE.G., TeehanB.P.Principles of prescribing dialysis therapy: implementing recommendations from the National Cooperative Dialysis Study.Kidney Int1983; 23(Suppl 13): Sl13–22.
4.
LindsayR.M., SpannerE.A hypothesis: The protein catabolic rate is dependent upon the type and amount of treatment in dialyzed uremic patients.Am J Kidney Dis1989; 13: 382–9.
5.
LysaghtM.J., PollockC.A., HalletM.D., IbelsL.S., FarrellP.C.The relevance of urea kinetic modeling to CAPD.ASAIO Trans1989; 35: 784–90.
6.
BlakeP.G., SombolosK., AbrahamG.Lack of correlation between urea kinetic indices and clinical outcomes in CAPD patients.Kidney Int1991; 39: 700–6.
7.
KeshaviahP.R., NolphK.D., ProwantB.Defining adequacy of CAPD with urea kinetics. In: KhannaR., NolphK.D., ProwantB.F., TwardowskiZ.J., OreopoulosD.G., eds. Advances in peritoneal dialysis.Toronto: Peritoneal Dialysis Bulletin, 1990; 6: 173–7.
8.
HartyJ.C., BoultonH., UttleyL., HeelisN., VenningM., GokalR.Limitations of urea kinetic modelling as predictors of nutritional and dialysis adequacy in CAPD.Am J Nephrol1993; 13: 454–63.
9.
HartyJ., FaragherB., VenningM., GokalR.Urea kinetic modeling exaggerates the relationship between nutrition and dialysis in CAPD patients (The hazards of cross-sectional analysis).Perit Dial Int1995; 15: 105–9.
10.
HartyJ., BoultonH., FaragherB., VenningM., GokalR.The influence of small solute clearance on dietary protein intake in continuous ambulatory peritoneal dialysis patients: A methodologic analysis based on cross-sectional and prospective studies.Am J Kidney Dis1996; 28: 553–60.
11.
ArchieJ.P.Mathematic coupling of data: a common source of error.Ann Surg1981; 193: 296–303.
12.
SteinA., WallsJ.The correlation between Kt/V and protein catabolic rate -a self-fulfilling prophecy.Nephrol Dial Transplant1994; 9: 743–5.
13.
UehlingerD.E.Another look at the relationship between protein intake and dialysis dose.J Am Soc Nephrol1996; 7: 166–8.
14.
LowrieE.G.Thoughts about judging dialysis treatment: Mathematics and measurements, mirrors in the mind.Semin Nephrol1996; 16: 242–62.
15.
GotchF.Dependence of normalized protein catabolic rate on KtN in continuous ambulatory peritoneal dialysis: not a mathematical artifact.Perit Dial Int1993; 13: 173–5.
16.
GotchF.A positive correlation of PCRN to KtN in cross-sectional studies is not proof of a causal relation ship.Perit Dial Int1995; 15: 274–85.
17.
DanekS.J., LynchJ.P., WegJ.G., DanztkerD.R.The dependence of oxygen uptake on oxygen delivery in the adult respiratory distress syndrome.Am Rev Respir Dis1980; 122: 387–95.
18.
RoncoJ.J., PhangP.T., WalleyK.R., WiggsB., FenwickJ.C., RussellJ.A.Oxygen consumption is independent of changes in oxygen delivery in severe adult respiratory disease syndrome.Am Rev Respir Dis1991; 143: 1267–73.
19.
PhangP.T., CunninghamK.F., RoncoJ.J., WiggsB.R., RussellJ.A.Mathematical coupling explains dependence of oxygen consumption on oxygen delivery in ARDS.Am J Respir Crit Care Med1994; 150: 318–23.
20.
LindsayR.M., SpannerE., HeidenheimR.P.Which comes first, Kt/V or PCR -chicken or egg?Kidney Int1992; (Suppl 38): S32–6.
21.
HeimbürgerO., TranæusA., BergströmJ., LindholmB.The effect of increasing PD on Kt/V, protein catabolic rate, and serum albumin (Abstract).Perit Dial Int1992; 12(Suppll): S19.
22.
BurkartJ., JordanJ., GarchowS., JonesM.Using a computer kinetic program to prescribe PD (Abstract).Perit Dial Int1994; 14(Suppll): S77.
23.
MalhotraD., TzamaloukasA.H., MurataG.M., FoxL., GoldmanR.S., AvasthiP.S.Serum albumin in continuous peritoneal dialysis: its predictors and relationship to urea clearance.Kidney Int1996; 50: 243–9.
24.
BlakeP.G.Dependence of normalized protein catabolic rate on KtN in CAPD: not a mathematical artifact (Letter).Perit Dial Int1994; 14: 405–6.
25.
RodbyR., FiranekC.A., ChengY.G., KorbetS.M.Reproducibility of studies of peritoneal adequacy.Kidney Int1996; 50: 267–71.
26.
StrattonH.H., FeustelP.J., NewellJ.C.Regression of calculated variables in the presence of shared measurement error.J Appl Physiol1987; 62: 2083–93.
BergströmJ., AlvestrandA., LindholmB., TranæusA.Relationship between KtN and protein catabolic rate is different in continuous peritoneal dialysis and hemodialysis patients (Abstract).J Am Soc Nephrol1991; 2: 358.
29.
BlakeP.G., LindsayR.M., SpannerE.Factors modifying the relationship between KtN urea and normalized protein catabolic rate in CAPD (Abstract).J Am Soc Nephrol1993; 4: 398.
30.
PanzettaG.Protein intake does not depend on the dose of dialysis delivered -provided KtN is adequate.Nephrol Dial Transplant1995; 10: 2286–9.
31.
NolphK.D., KeshaviahP., EmersonP.A new approach to optimizing urea clearance in hemodialysis and continuous ambulatory peritoneal dialysis.ASAIO J1995; 41: M446–51.
32.
MactierR.A., PerryM., HendersonI.S.Relationships between dialysis quantification and normalized protein catabolic rate in peritoneal dialysis.Perit Dial Int1993; 13(Suppl 2): S508–11.
