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FILLERS: Anaemia doesn't predict iron deficiency among toddlers BMJ 2005; 331: 0-f [Full text]

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"Serum haemoglobin" for anaemia screening

Kenneth Campbell   (1 July 2005)

Aneamia does not predict iron deficiency among toddlers

oscar,m jolobe   (2 July 2005)

Anaemia predicts a response to iron therapy

Charlotte M Wright   (6 July 2005)

The response to a therapeutic trial as a diagnostic aid

oscar m jolobe   (11 July 2005)

Bottom line

John Hain   (27 July 2005)

"Serum haemoglobin" for anaemia screening 1 July 2005
Kenneth Campbell, Clinical Information Officer (posted in private capacity) Leukaemia Research Fund, WC1N 3JJ Send response to journal: Re: "Serum haemoglobin" for anaemia screening	Dear Sir, I was most interested to read the POEMS report on the lack of sensitivity and specificity of anaemia for iron deficiency in children. I was a little alarmed at the suggestion that SERUM haemoglobin levels are used to screen for anaemia - the normal PLASMA haemoglobin level is on the order of 15,000 times lower than the BLOOD haemoglobin level, which of course is the parameter usually measured for screening for anaemia. Yours, Competing interests: None declared
Aneamia does not predict iron deficiency among toddlers 2 July 2005
oscar,m jolobe, retired geriatrician 1 the Lodge, 842 Wilmslow road, Didsbury, M20 2RN Send response to journal: Re: Aneamia does not predict iron deficiency among toddlers	If anaemia is an insensitive marker of iron deficiency(1)(2), which of the other commonly used red blood cell(RBC) indices is best able to identify iron deficiency in at risk non-anaemic subjects? A tentative answer to this question came from a study in which 462 toddlers were screened, and, among them 60 proved to be iron deficient. Within the latter group, even in isolation(ie even in the absence of anaemia or mean cell volume below the screening threshold level of 75 fl), a mean cell haemoglobin(MCH) of < 25 pg proved capable of identifying the presence of iron deficiency, whilst an MCV of < 75 fl, on its own, did not appear to be associated with iron deficiency in non-anaemic subjects(2). A more convincing way of comparing the predictive value of the two RBC indices would be to target, for the purpose of study, non-anaemic subjects derived from a population at high risk of iron deficiency, such as toddlers being weaned on low iron content feeds or those being fed almost exclusively on unmodified cow's milk(3), or toddlers of South Asian origin(4). The question is one worth addressing, given the fact that, even in the absence of anaemia, iron deficiency is capable of causing neurodevelopmental abnormalities(5). Yours sincerely OMP Jolobe MRCP(UK) Refernces (1)White K Anemia is a poor predictor of iron deficiency among toddlers in the United States Pediatrics 2005:315-20 (2) Wright CM., Kelly J., Trail A., Parkinson KN., Summerfield G The diagnosis of borderline iron deficiency:results of a therapeutic trial Archives of Disease in Childhood 2004:89:1028-31 (3) Daly A., MacDonald A., Aukett A ., et al Prevention of anaemia in inner city toddlers by an iron supplemented cow's milk formula Archives of Disease in Childhood 1996:75:9-16 (4)May R., Aukett A Population screening for anaemia in the inner city Ambulatory Child Health 2000:6:8-11 (5) Walter T., Kovalskys J., Stekel A Effect of mild iron deficiency on infant mental development scores Journal of Pediatrics 1983:102:519-22 Competing interests: None declared
Anaemia predicts a response to iron therapy 6 July 2005
Charlotte M Wright, Senior Lecturer in community Child Health Glasgow University G3 8SJ Send response to journal: Re: Anaemia predicts a response to iron therapy	I am grateful to Oscar Jolobe for drawing attention to our recent study (1) which was published after the Pediatrics paper (2) was accepted for publication. Ours was a before and after intervention study in contrast to the Pediatrics study, which although classified by the authors of the POEM as a trial, was in fact simply a cross sectional cohort study. We also found only a modest overlap between anaemia and iron deficiency, but to our surprise both total and mean cell haemoglobin proved powerful predictors of a therapeutic response to iron. Unless supposed markers of iron deficiency are tested against a therapeutic response, all that is really being demonstrated is how poorly most of them actually function as indicators of iron deficiency. Reference List 1. Wright CM, Kelly J, Trail A, Parkinson KN, Summerfield G. The diagnosis of borderline iron deficiency: results of a therapeutic trial. Arch.Dis.Child 2004;89:1028-31. 2. White KC. Anemia is a poor predictor of iron deficiency among toddlers in the United States: for heme the bell tolls. Pediatrics 2005;115:315-20. Competing interests: I am the first author on a research study that drew precisely opposite conclusions
The response to a therapeutic trial as a diagnostic aid 11 July 2005
oscar m jolobe, retired geriatrician 1 The Lodge, 842 Wilmslow Road Didsbury manchester, M20 2RN Send response to journal: Re: The response to a therapeutic trial as a diagnostic aid	The concept that the response to a therapeutic trial might be a decisive diagnostic aid(1) is one that deserves greater recognition, given the fact that it is applicable to a wide variety of disciplines. For, example, the cost-effectiveness of establishing the diagnosis of left ventricular(LV) diastolic failure would be considerably enhanced if, for non-research purposes, instead of a reliance on "evidence of abnormal left ventricular relaxation, filling, diastolic distensibility or diastolic stiffness"(2)when evaluating patients in whom suspected LV failure co- existed with normal LV ejection fraction, recourse was made to the clinical and, especially, radiographic response to antifailure therapy, the radiographic parameters being those recently validated as being highly predictive of LV failure(3). Yours sincerely OMP Jolobe References (1) Wright CM., Kelly J., Trail A., Parkinson KN., Summerfield G The diagnosis of borderline iron deficiency:results of a therapeutic trial Archives of Disease in Childhood 2004:89:1028-31 (2)European Study Group on Diastolic Heart Failure How to diagnose diastolic heart failure European Heart Journal 1998:19:990-1003 (3) Knudsen C., Omland T., Clopton P et al Diagnostic value of B-Type Natriuretic Peptide and Chest Radiographic Findings in Patients with Acute Dyspnoea American Journal of Medicine 2004:116:363-8 Competing interests: None declared
Bottom line 27 July 2005
John Hain, GP HG3 3AJ Send response to journal: Re: Bottom line	Forgive me if I am being obtuse, but the paragraph entitled "bottom Line" seems to contain a couple of misleading statements: while it is unsurprising that we cannot assume iron stores are always reflected by haemoglobin levels, it is perplexing to hear that haemoglobin itself is being branded an unreliable marker of anaemia. Presumably this was a typing error? Thank you. Competing interests: None declared