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PRACTICE: Matthew J Thompson, Anthony Harnden, and Chris Del Mar Excluding serious illness in feverish children in primary care: restricted rule-out method for diagnosis BMJ 2009; 338: b1187 [Full text]

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Research is needed in the natural course of fever and its spatial distribution throughout the body over time.

Wouter Havinga   (22 April 2009)

Ruling in or ruling out are not the best ways of making a decision

Harry Hall   (22 April 2009)

Likelihood ratios are better than sensitivity and specificity

Wilfrid Treasure   (25 April 2009)

Specific tools to manage complex consultations in general practice

Jose L. Turabian   (26 April 2009)

Early red flags

Nicholas Devine   (26 April 2009)

A sample of urine is not likely to be available when child 2 is seen

Andrew M Ross   (5 May 2009)

Research is needed in the natural course of fever and its spatial distribution throughout the body over time. 22 April 2009
Wouter Havinga, GP locum GL6 6JL Send response to journal: Re: Research is needed in the natural course of fever and its spatial distribution throughout the body over time.	Parents need to be given a proper explanation of the fever process and safe follow-up advice.   Observational studies are needed to confirm the observation that fevers start from the head and thorax area and work their way down into the body, into the limbs, hands and feet. The child will be shivery and feeling cold when the feet are still cold, even though the ear thermometer is indicating a high temperature. I am aware of one such study of viral fever patterns (however, analgesics were used). (1)   By supporting the physiological fever process the parent can help the child feel better sooner. Once the feet and hands are warm, the child perks up again, the fever process starts to subside and the child will want to take some clothing or any blankets off,  until the next feverish episode starts. (usually in the late evening).   The lethargy can be explained to parents by making the comparison that running a temperature is like running a distance. It takes energy to raise the temperature of the body and that is why the breathing goes quicker and the heart rate is up. Therefore it is important to support the fever process so that it can resolve itself sooner than when people try to "get the temperature down", in which case the child is having to expend energy unnecessarily for longer periods of time. However in a serious bacterial infection the energy demand might be more enduring, not following a rhythm and as such a serious bacterial infection fever pattern / process might be different from common viral infections.   Rather than advising parents on "controlling" or "managing" the temperature, parents have to check every few hours, and through the night, whether the child can sit upright with the legs straight out and look down (ref. overt meningeal signs) and check for a non-blanching rash (ref. overt septicaemia), anywhere on the body . Furthermore in line with the authors (2) I agree to pre-empt these two conditions by advising the patents that in case there is ongoing lethargy to have the child assessed.    This bacterial fever pattern seem to contrast to viral feverish episodes in my experience, in which the child seem to periodically brighten up after establishing a raised temperature including the hands and feet   1.      Suzuki E, Ichihara K, Johnson AM. Natural Course of Fever During Influenza Virus Infection in Children. Clin Pediatr (Phila) 2007 46: 76-79 http://cpj.sagepub.com/cgi/content/abstract/46/1/76 2.      Thompson MJ,  Harnden A,  Del Mar C. Excluding serious illness in feverish children in primary care: restricted rule-out method for diagnosis. BMJ 2009 338: b1187   Email;  wouter.havinga@gmail.com    Competing interests: None declared
Ruling in or ruling out are not the best ways of making a decision 22 April 2009
Harry Hall, Retired physician EX1 2HW Send response to journal: Re: Ruling in or ruling out are not the best ways of making a decision	Boyko (1) and Wen-Chung Lee (2) have explained that the usual approaches of trying to rule in (tests of high specificity) or rule out (tests of high sensitivity)a particular disease are not optimal from the point of view of getting the best outcome. Sensitivity, specificity (combined as likelihood ratio), considered with incidence of the disease (Bayes), together with some measure of utility do better. This is common sense. To quantitate the various factors and compute the right policy requires better IT back up than we have at present. This is research that would be well worth while. 1.Boyko EJ. Ruling out or ruling in disease with the most sensitive or specific diagnostic test: Short cut or Wrong turn? Med.Decis.Making 1994; 14:175 2.Wen-Chung Lee. Selecting diagnostic tests for ruling out or ruling in disease: the use of the Kullback-Leibler distance Int.J. Epidemiol. 1999; 28:521 Competing interests: None declared
Likelihood ratios are better than sensitivity and specificity 25 April 2009
Wilfrid Treasure, GP Principal MMG, EH4 4PL Send response to journal: Re: Likelihood ratios are better than sensitivity and specificity	This paper gives figures for sensitivity which abound in the literature and tell us about the test in a patient with the disease. What we clinicians really need are figures about prevalence and likelihood ratios which are rare in the literature and tell us about patients like the one in front of us. The case studies acknowledge the difficulty of picking out the occasionally seriously ill child and sending them to hospital. However, the statistics do not clarify as much as they might. I think that is because sensitivities only tell us anything in retrospect - once the mengingitis is diagnosed - but are of little use prospectively. A knowledge of prevalence and likelihood ratios gives one a scientific basis for certainty and, more often, uncertainty. Suppose we had a symptom or sign for meningitis with a sensitivity of 67% and specificity of 67%: that might sound useful. But calculate the positive and negative likelihood ratios: assuming an initial probability of meningitis of 1%, a negative finding tells you that the patient has 0.5% chance of having meningitis and a positive finding tells you they have a 2% chance of having meningitis. We're not much further forward with diagnosis. Do we settle for missing half the patients with meningitis? Do we settle for 50 emergency referrals to hospital for every one case? I think GPs are aware of this, although in my experience few rattle off the figures. It might be that there are clinicians with wonderful diagnostic acumen who get these diagnoses right all the time but it surely can't be as a result of such symptoms and signs as these. Are they better at gestalt, understanding the time course, safey netting, communicating? Andrew Polmear's book, Evidence-based diagnosis in primary care (Elsevier, London, 2008) indicates which likelihood ratios are known, the many that are not and their usefulness or otherwise. Wilfrid Treasure Competing interests: None declared
Specific tools to manage complex consultations in general practice 26 April 2009
Jose L. Turabian, General Practitioner Guadarrama s/n. 45313 Toledo, Spain. Send response to journal: Re: Specific tools to manage complex consultations in general practice	The uncertainty of diagnostic is often represented in terms of probability or normative reasoning, and evidence-based medicine (EBM) is the most successful efforts to apply statistical theory to clinical decision (1). However, the human reasoning under conditions of uncertainty is not normative, this thinking may be desirable in the game of poker, but not in family medicine. Solomon in the “Judgment of Salomon” (2) used the knowledge of common sense to fill the gaps in the evidence, and to obtain more evidence. A decision "good" is one whose enforcement reduces uncertainty, usually to get more information, or reduce the impact of uncertainty. Different problems types need different knowledge types, and GPs’ generalist role, in contrast with specialisation, is more often dealing with decision-making in a complex systems enviroment, where cuantitative evidence based medicine (EBM) and evidence-based guidelines are not enough, and other scientific paradigms, which include patterns, structures, and process identification, etc., are need (3). In addition to the sequence of diagnostic by symptomatic criteria, which follows the medical model of disease, there are other forms of qualitative diagnostic approach, through the holistic impression, that the physician obtains from patient's situation (BOX-1). Here, the context is that controls and directs the clinical análisis (4). 1.- Smith CS, Douglas SP. Hen you hear hoof beats: four principles for separing zebras from horses. J Am Board Fam Pract. 2000;13:424- 9.[Medline] 2.- Solomon. http://en.wikipedia.org/wiki/Solomon 3.- Martin CM, Sturmberg JP. General practice — chaos, complexity and innovation. Med J Aust 2005; 183 (2): 106-109 4.-Turabián Fernández JL, Pérez Franco B. Una forma de hacer operativo el pragmatismo clínico: sistematización del modo de acción de los médicos competentes. Med Clin (Barc). 2005;124:476.[Artículo] BOX 1 Some qualitative tools to manage complex consultations in Family Medicine 1.-Context-centered medical care; 2.-Experience; 3.-Continuity of care; 4.-Common sense; 5.-Strategy planning; 6.-Self-esteem, empowerment; 7.-Emotion and intuition; 8.-Ethtic; 9.-Patients and community participation; 10.-Wait-and-See; 11.-Doctor-patient communication; 12.- Contex-Centered Medical Record E-mail: jturabianf@meditex.es Competing interests: None declared
Early red flags 26 April 2009
Nicholas Devine, GP principal Bramhall Park Medical Centre sk7 3ep Send response to journal: Re: Early red flags	The labelled early red flags are quite disappointing, in my experience these are all seen in childhood fevers of whatever origin and of little practical use except perhaps to the legal profession. Competing interests: None declared
A sample of urine is not likely to be available when child 2 is seen 5 May 2009
Andrew M Ross, general practitioner Northfield Health Centre, 15 St Heliers Road, Northfield, Birmingham B31 1QT Send response to journal: Re: A sample of urine is not likely to be available when child 2 is seen	The authors of this article lose touch with real clinical practice when stating that 'Dip stick urine testing is negative' when referring to child 2. In my experience (and that of other GPs I have asked) it would be extremely unlikely for a withdrawn, feverish two-year old child to be able produce a urine sample for immediate testing at a general practice consultation. Competing interests: None declared