We would like to comment on strength of conclusions of the recent
publication by Dr Brusasco et al,[1] particularly that no consideration
is given to how the results compare to the balance of evidence that
exists.
The paper’s conclusions imply superior efficacy of tiotropium over
salmeterol in patients with COPD by emphasising endpoints in which
tiotropium shows a difference compar...
We would like to comment on strength of conclusions of the recent
publication by Dr Brusasco et al,[1] particularly that no consideration
is given to how the results compare to the balance of evidence that
exists.
The paper’s conclusions imply superior efficacy of tiotropium over
salmeterol in patients with COPD by emphasising endpoints in which
tiotropium shows a difference compared with placebo, but salmeterol does
not. However, as this combined analysis fails to show clinically relevant
differences between salmeterol and tiotropium we believe such conclusions
to be somewhat exaggerated.
We note that for certain endpoints, salmeterol in this analysis
failed to show a difference compared with placebo. While these results
were disappointing, they are not reflective of the wealth of evidence that
exists from previous placebo-controlled studies of up to 12 months
duration with salmeterol. These studies show significant improvements in
lung function, quality of life, breathlessness and reliever use, and
exacerbations compared with placebo/usual therapy.[2-9]
A recent meta-analysis of nine double-blind studies including over
3500 patients with COPD confirms that salmeterol has a significant and
sustained bronchodilator effect with no evidence of tolerance compared
with placebo, and significantly reduces the risk of exacerbations (22%
reduction compared with placebo/usual therapy).[9,10]
Lastly, and we feel importantly, this study and analysis introduces a
new definition of COPD exacerbations with no explanation for the
rationale, nor a justification for the validity of this. Previous studies
have either used health utilisation [2,11] (event measured is sufficiently
important for the patient to seek medical help and the physician to feel
the patient needs treatment), or exacerbations are defined by a
combination of major and minor symptoms.[12,13] By not using any of these
definitions, it is difficult for the clinician to evaluate any relative
efficacy of tiotropium in reducing exacerbations, compared to other
therapeutic agents currently available.
In conclusion, it is important to reflect on whether the findings of
this study are supported by what we already know. We feel it is important
to state that for this publication and for the results seen for
salmeterol, this is clearly not the case.
References
(1) Brusasco V, Hodder R, Miravitlles M, Korducki L, Towse L, Kesten S.
Health outcomes following treatment for six months with once daily
tiotropium compared with twice daily salmeterol in patients with COPD.
Thorax 2003;58:399-404.
(2) Calverley P, Pauwels R, Vestbo J, et al. Combined salmeterol and
fluticasone in the treatment of chronic obstructive pulmonary disease: a
randomised controlled trial. Lancet 2003;361:449–456.
(3) Mahler DA, Wire P, Horstman et al. Effectiveness of fluticasone
propionate and salmeterol combination delivered via the Diskus device in
the treatment of chronic obstructive pulmonary disease. Am J Respir Crit
Care Med 2002;166:1084-1091.
(4) Hanania NA, Knobil K, Watkins M, Wire P, Yates J, Darken P. The efficacy
and safety of fluticasone propionate 250mcg/salmeterol 50mcg combined in
the Diskus inhaler for the treatment of chronic obstructive pulmonary
disease. Chest 2003;in press.
(5) Stockley RA, Chopra N. Salmeterol, added to usual therapy is an
effective bronchodilator over 12 months of treatment in chronic
obstructive pulmonary disease (COPD). Eur Respir J 2002;20 (suppl
38):241s.
(6) Stockley RA, Davies EA, Sondhi S, Rice L. Salmeterol provides sustained
health status improvement over 12 months in patients with COPD. Eur Respir
J 2002;20(suppl 38):241s.
(7) Jones PW, Bosh TK. Quality of life changes in COPD patients treated with
salmeterol. Am J Respir Crit Care Med 1997;155:1283–1289.
(8) Boyd G, Morice AH, Pounsford JC, Siebert M, Peslis N, Crawford C. An
evaluation of salmeterol in the treatment of chronic obstructive disease.
Eur Respir J 1997;10(4):815–821.
(9) Stockley RA, Whitehead PJ, Williams MK, Hagan G. Serevent 50mcg bid
significantly reduces moderate-severe exacerbations in patients with all
severities of COPD. Am J Respir Crit Care Med 2003;167(7):A949.
(10) Stockley RA, Whitehead PJ, Williams MK, Hagan G. Serevent 50mcg bid
significantly increases trough FEV1 in COPD up to 12 months without loss
of effect. Am J Respir Crit Care Med 2003;167(7):A95.
(11) Szafranski W, Cukier A, Ramirez A et al. Efficacy and safety of
budesonide/formoterol in the management of chronic obstructive pulmonary
disease. Eur Respir J 2003;21:74-81.
(12) Anthonisen RN, Manfreda J, Warren CPW, Hershfield ES, Harding GKM,
Nelson NA. Antibiotic therapy in exacerbations of chronic obstructive
pulmonary disease. Ann Intern Med 1987;106:196-204.
(13) Seemungal TAR, Donaldson GC, Bhowmik A et al. Time course and recovery
of exacerbations in patients with chronic obstructive pulmonary disease.
Am J Respir Crit Care Med 2000;161:1608-1613.
With great interest, we read the guidelines for the management of
suspected acute pulmonary embolism (PE) by the British Thoracic Society
(June issue 2003).[1] In the discussion of treatment options, the
guidelines state that surgical embolectomy should only be considered in
cases with absolute contraindications to thrombolysis, which is rarely an
important consideration in a life-threatening situat...
With great interest, we read the guidelines for the management of
suspected acute pulmonary embolism (PE) by the British Thoracic Society
(June issue 2003).[1] In the discussion of treatment options, the
guidelines state that surgical embolectomy should only be considered in
cases with absolute contraindications to thrombolysis, which is rarely an
important consideration in a life-threatening situation.
In contrast to the guidelines, a recent study of surgical pulmonary
embolectomy with the use of normothermic cardiopulmonary bypass
liberalized these criteria. Patients with anatomically extensive pulmonary
embolism and concomitant right heart failure were included and
demonstrated a 1-month mortality rate of only 11% following surgical
intervention.[2] The improved survival rates in this case series as
compared to previous reports [3,4] may be related to advances in surgical
technique, patient selection and the experience of cardiac surgeons and
cardiac anesthesiologists with this operation. However, this report no
longer confines surgical pulmonary embolectomy to a treatment of last
resort reserved for clinically desperate circumstances. In contrast,
centers that are experienced in performing pulmonary embolectomy may
consider utilizing this therapeutic intervention more liberal in order to
improve morbidity and mortality of patients suffering from severe PE.
References
(1) British Thoracic Society guidelines for the management of
suspected acute pulmonary embolism. Thorax 2003;58(6):470-483.
(2) Aklog L, Williams CS, Byrne JG, Goldhaber SZ. Acute Pulmonary
Embolectomy: A Contemporary Approach. Circulation 2002;105(12):1416-1419.
(3) Heit JA, Silverstein MD, Mohr DN, Petterson TM, O'Fallon WM, Melton LJ,
3rd. Predictors of survival after deep vein thrombosis and pulmonary
embolism: a population-based, cohort study. Arch Intern Med 1999;159(5):445-53.
(4) Doerge H, Schoendube FA, Voss M, Seipelt R, Messmer BJ. Surgical
therapy of fulminant pulmonary embolism: early and late results. Thorac
Cardiovasc Surg 1999;47(1):9-13.
One of the paradoxes of modern medicine is the rapid growing
incidence of immune-based diseases over the last half of the century.
Despite enormous advances in our understanding of the immune system, and
our ability to manipulate immunity in experienced animals and man, we have
not been able to curtail these diseases. In fact, it is becoming
increasing evident that immune hypersensitivity response...
One of the paradoxes of modern medicine is the rapid growing
incidence of immune-based diseases over the last half of the century.
Despite enormous advances in our understanding of the immune system, and
our ability to manipulate immunity in experienced animals and man, we have
not been able to curtail these diseases. In fact, it is becoming
increasing evident that immune hypersensitivity responses are central to
the pathogenesis of many of the most common diseases of the 21st century
including atherosclerosis, diabetes, obesity, and arthritis . Included in
this epidemic are atopy-associated disorders (such as asthma, eczema,
allergic rhinoconjunctivitis, and food allergies), which have skyrocketed
in prevalence. While genetic factors certainly contribute to the
pathogenesis of these diseases, there is emerging evidence that their
rising incidence is related to changes in western lifestyle. ADAM 33, a
new asthma gene is a major breakthrough and would definitely help in the
management of asthma.
The efficacy and clinical effectiveness of homeopathy engenders
considerable debate; it is therefore essential that clinical trials are
accurately interpreted and reported. The recent publication by White et al.[1] has highlighted this issue.
The study, assessing classical homeopathy
as an adjunctive treatment for childhood asthma concluded that, based on
the primary outcome (the active qua...
The efficacy and clinical effectiveness of homeopathy engenders
considerable debate; it is therefore essential that clinical trials are
accurately interpreted and reported. The recent publication by White et al.[1] has highlighted this issue.
The study, assessing classical homeopathy
as an adjunctive treatment for childhood asthma concluded that, based on
the primary outcome (the active quality of living subscale of the
Childhood Asthma Questionnaire) classical homeopathy was not superior to
placebo. We disagree with this conclusion. The scale used to assess the
primary outcome was inappropriate [it does not distinguish between
asthmatics and non-asthmatics [2] and is more suitable as a cross-sectional
measure rather than a longitudinal outcome; and the ability to identify
any therapeutic improvement was severely reduced due to ceiling/flooring
effects in both the primary and some secondary outcome data. For example,
baseline scores identified that the study population had good quality of
life, and that two of the three age groups studied had mild asthma.
Therefore, any therapeutic improvement would be hard to identify let alone
quantify.
Other design issues were apparent, e.g. no data was reported on
homeopathic exacerbations (an indicator of the healing response), and the
security of blinding was not assessed. Yet despite these limitations, some
encouraging therapeutic effects were apparent. For example, a clinically
relevant improvement in asthma severity (unadjusted scores) was seen in
two of the three groups and a favourable pattern in the days off
school/days attended was seen in the homeopathic treated children
(although no data was presented).
We suggest that a balanced and accurate conclusion to this data would
be that no definitive conclusions could be drawn but that further
investigation is needed. We therefore hope that the authors’ inaccurate
conclusions neither dampens future research, nor bias future systematic
reviews.[3]
References
(1) White A, Slade P, Hunt C, Hart A and Ernst E. Individualised
homeopathy as an adjunct in the treatment of childhood asthma ;a
randomised placebo controlled trial. Thorax 2003: 58:317-321.
(2) French DJ, Christie MJ, Snowden AJ. The reproducibility of the
childhood asthma questionnaires: measures of aulity of life fro children
with asthma aged 4-16 years. Quality of Life Research 1994;3:215-224.
(3) White, P, Lewith G, Berman B and Birch S. Reviews of acupuncture for
chronic neck pain : pitfalls in conduting systematic reviews. Rheumatology
2002;41:1224–1231.
Dr Leckridge[1] is correct to state that the children in the study had
mild to moderate symptoms of asthma at the time of recruitment. Children
with more severe symptoms were excluded at the request of the Ethics
Committee, because of the risks that could arise if they stopped their
conventional medication. Our study tested homeopathy as an adjunct to
standard medical management, not an alternative.
Dr Leckridge[1] is correct to state that the children in the study had
mild to moderate symptoms of asthma at the time of recruitment. Children
with more severe symptoms were excluded at the request of the Ethics
Committee, because of the risks that could arise if they stopped their
conventional medication. Our study tested homeopathy as an adjunct to
standard medical management, not an alternative.
We expected that children
given homeopathy might be able to reduce their conventional medication by
standard guidelines, but could not find any evidence that this occurred.
We acknowledged that there were trends in favour of the homeopathy group
in some measures, but not in the primary measure, which was recommended by
the questionnaire’s author as the most sensitive to change. We were
careful not to over-generalise from our study, and certainly did not claim
that homeopathy is ineffective in different samples of patients with
asthma, for example those with more severe symptoms.
Reference
(1) Leckridge R. Homeopathy and childhood asthma [electronic response to White et al. Individualised homeopathy as an adjunct in the treatment of childhood asthma: a randomised placebo controlled trial] thoraxjnl.com 2003 http://thorax.bmjjournals.com/cgi/eletters/58/4/317#59
This study of quality of life in children with asthma treated with
homeopathy is fatally flawed.[1] The Childhood Asthma Quality of Life
instrument used was validated in a study by French et al.[2] The children entered into White’s study had
scores consistent with those of normal children who don’t have asthma. For
a statistically significant improvement to occur in this score, the
treated group wo...
This study of quality of life in children with asthma treated with
homeopathy is fatally flawed.[1] The Childhood Asthma Quality of Life
instrument used was validated in a study by French et al.[2] The children entered into White’s study had
scores consistent with those of normal children who don’t have asthma. For
a statistically significant improvement to occur in this score, the
treated group would have to develop scores of around 100% ie better than
normal, non-asthmatic children. This is clearly highly unlikely. In
addition, a similar “ceiling effect” applies to the PEFR readings – again,
at entry they were 100.4% and 96.9% of expected for the verum and placebo
groups, respectively.
This is a very poor quality trial which does absolutely nothing to further
our understanding of the potential value of homeopathic treatment in
children with asthma. In fact, the press release from the journal has been
picked up by the media and used to support a headline of “Homeopathy of no
use in Asthma”.
Publishing this quality of research at best does not improve our necessary
evidence base, and, at worst, contributes to the denial of services which
may indeed be of value to patients. A close analysis of the study shows
that the treatment group had a trend to better outcomes than the placebo
group. If this were a pilot study, it would be indicating that there is
indeed a potential benefit to asthmatic children from homeopathy which
should be investigated with a proper trial of good methodological quality.
References
(1) A White, P Slade, C Hunt, A Hart, and E Ernst. Individualised homeopathy as an adjunct in the treatment of childhood asthma: a randomised placebo controlled trial. Thorax 2003; 58:317-321.
(2) French DJ, Christie MJ, Sowden AJ. The reproducibility of the childhood asthma questionnaires: measures of quality of life for children with asthma aged 4–16 years. Qual Life Res 1994;3:215–24.
It is indeed a pity that there was no comparison between continuous
aminophylline and continuous salbutamol. The authors did not make it very
clear why they did not choose this option. The conclusion that there is
some favourable outcome with aminophylline is therefore, in my opinion, too
strong for the data they present.
Another query is: Why did the authors use aminophylline, instead of
theofylline, wit...
It is indeed a pity that there was no comparison between continuous
aminophylline and continuous salbutamol. The authors did not make it very
clear why they did not choose this option. The conclusion that there is
some favourable outcome with aminophylline is therefore, in my opinion, too
strong for the data they present.
Another query is: Why did the authors use aminophylline, instead of
theofylline, with the risk of provoking an allergy to ethylenediamine?
Reference
(1) Hardy C, Schofield O, George CF: Allergy to aminophylline. Br Med J
(Clin Res Ed) 1983 Jun 25;286(6383):2051-2.
We thank Dr Chanarin for his interest in the new Asthma Guideline.
We will answer the points made in the order in which he raises them.
1. The quoted studies on breast-feeding appear to be equivocal in
terms of the protective effect on asthma, but both show protection against
wheezing illness in the first years of life. The recommendation in the
guideline specifies such wheezing illne...
We thank Dr Chanarin for his interest in the new Asthma Guideline.
We will answer the points made in the order in which he raises them.
1. The quoted studies on breast-feeding appear to be equivocal in
terms of the protective effect on asthma, but both show protection against
wheezing illness in the first years of life. The recommendation in the
guideline specifies such wheezing illnesses rather than asthma and is
therefore justified. We do agree that this is a difficult area,
principally because of the problem of distinguishing asthma from the other
causes of childhood wheeze. We believe other pertinent data will be
available for the next revision of the guideline, and we will consider
whether the current recommendation should be changed or its grading
altered.
2. Dr Chanarin is wrong to accuse us of ignoring the conclusions of
the Cochrane reviews on house dust mite (HDM) avoidance. The second,
updated Cochrane report concludes that definitive evidence is still
lacking, that routine use of HDM control measures cannot be recommended,
and suggests possible benefit from “physical” methods as opposed to
“chemical”. Our paragraphs on the topic reproduce these views. Faced
with this conclusion, but knowing that patients and parents of asthmatic
children may well wish to take reasonable measures to reduce HDM exposure,
we simply listed methods which might be used by those who feel that they
wish to follow this course despite the uncertain benefits. We do not
recommend that HDM control is advocated routinely.
3. There has been little information available regarding the criteria
for moving between treatment steps (although we note with interest the
recent publication on monitoring sputum eosinophilia). The conventional
advice includes, among other things, the advice that treatment should
minimize bronchodilator requirements, and using a bronchodilator more than
once a day is often taken as indicating the need to step up. However,
this is not supported by any hard data. In the guideline, we do not
suggest 10-12 puffs a day as the correct threshold, and Dr Chanarin will
recognise that no such recommendation is made. This was simply quoted in
the text in relation to one paper which had addressed the issue of
assessing asthma control. In retrospect, we can see how this might be
taken in a different context and we will address it in the next revision.
4. Regarding intravenous Aminophylline, Dr Chanarin seems to take
the opposite stance to his position on HDM avoidance. Here he wants us to
ignore the available evidence. The papers on Aminophylline are not all
old (several of them are from the 1990s) and the Cochrane review judged
them to be of moderate quality rather than poor. We therefore have to
take note of these studies and it is difficult to recommend Aminophylline
in the face of the consistent absence of benefit which they show,
particularly when there are better alternatives. We too recognise the
power of personal experience on this issue, but feel that intravenous
Aminophylline has been justifiably down-graded.
In relation to introducing the new pieces of advice to his hospital,
we can only say to Dr Chanarin that this is simply a guideline, and we
fully understand that each doctor must take responsibility for his own
treatment strategies. However, we can assure him that these
recommendations were all given careful thought and, whilst some may prove
to be wrong, we would hope that they are not rejected without equally
careful consideration.
We thank Dr Chanarin again for the attention he has obviously given
to the document and for taking the time to feed back to us.
Dr BG Higgins
Co-Chairman
British Thoracic Society/SIGN Asthma Guideline Committee
Dr G Douglas
Co-Chairman
British Thoracic Society/SIGN Asthma Guideline Committee
I read with interest the article of Tate et al. indicating that
exhaled condensates are acidic in patients with CF and become more acidic
during exacerbations. The data show differences in mean values (with some
overlap) and the hypothesis that the airways are acidic in these patients
seems plausible. However I am concerned that the condensate measurements
cannot give a reliable estimate of airway...
I read with interest the article of Tate et al. indicating that
exhaled condensates are acidic in patients with CF and become more acidic
during exacerbations. The data show differences in mean values (with some
overlap) and the hypothesis that the airways are acidic in these patients
seems plausible. However I am concerned that the condensate measurements
cannot give a reliable estimate of airway pH. Several studies have shown
that NH4+ is the predominant solute and buffer in condensates and that
most of this is derived from NH3 generated in the mouth.[1,3]
Furthermore, NH4+ concentrations are significantly reduced in patients
with inflammatory lung disease.[2] Low pH in the condensates may
therefore reflect decreased concentrations of NH4+ in the condensate.
Condensate NH4+ concentrations are presumably determined by the efficiency
with which NH3 is exchanged in the mouth and the condenser, and not by NH3
generated in the lungs (condensate concentrations of NH4+are very low in
patients with tracheostomies). These alterations in exchange could be due
to low salivary NH4+ concentrations or alterations in respiratory flow
rates. Interpretation of condensate pH is not possible unless the
contribution of oral NH4+ is determined and objective evidence is provided
for increased concentrations of inorganic and/or organic acids in the
respiratory droplets. It remains to be shown that acidification of the
condensate in patients with inflammatory disease is due to acidification
of the airways (to a pH as low as 4.6) rather than decreased exchange of
NH3 outside the lungs. The latter mechanism would seem much less relevant
to the severity or course of CF lung disease.
References
(1) Effros R, Hoagland K, Bosbous M, Castillo D, Foss B, Dunning M,
Gare M, Lin W, Sun F. Dilution of respiratory solutes in exhaled
condensates. Am J Respir Crit Care Med 2002;165:663–669.
(2) Hunt J, Fang K, Malik R, Snyder A, Malhotra N, Platts-Mills TAE,
Gaston B. Endogenous airway acidification: implications for asthma
pathophysiology. Am J Respir Crit Care Med 2000;161:694–699
(3) Hunt J, Erwin E, Palmer L, Vaughan J, Malhotra N, Platts-Mills TAE,
Gaston B. Expression and activity of pH-regulatory glutaminase in the
human airway epithelium. Am J Respir Crit Care Med 2001;165:101–107.
The New Guidelines use evidence based methodology
extensively. This methodology has been developed by the Scottish
Intercollegiate Guidelines Network and is not only well respected
but has been widely applied to develop other guidelines. The
guidelines use levels of evidence, I quote “Level A is: At least one
meta analysis, systematic review, or RCT rated as 1++ and directly
applicab...
The New Guidelines use evidence based methodology
extensively. This methodology has been developed by the Scottish
Intercollegiate Guidelines Network and is not only well respected
but has been widely applied to develop other guidelines. The
guidelines use levels of evidence, I quote “Level A is: At least one
meta analysis, systematic review, or RCT rated as 1++ and directly
applicable to the target population or A body of evidence
consisting principally of studies rated as 1+ and directly applicable
to the target population and demonstrating overall consistency of
results.”
How have these principles been applied?
The section on Primary prophylaxis makes only one grade A
recommendation and this is on breast feeding. In the evidence the
authors site two main pieces of evidence which contradict each
other. The first is a systematic review and a meta-analysis
involving 8183 subjects followed for 4 years which apparently
revealed a significant protective effect of breast feeding against the
development of asthma. The second study contradicts this. The
second study is in 1246 patients and found that there was a
reduction in early life wheeze but an increase in asthma at six
years. If the question is does breast feeding protect against the
subsequent development of asthma then the answer on the given
evidence is clearly undecided and surely no evidence based
advice can be given, certainly not level A guidance. What advice
should I give to a worried mother to be if she asks me what she
can do to prevent her child developing asthma?
The section on secondary prophylaxis is also confusing. House
dust mite control measures are reviewed and no less than two
Cochrane reviews are quoted. Both reviews concluded that current
physical and chemical methods are ineffective. By the SIGN
methodology a clear recommendation could be made at grade A
level that house dust mite control measures can not be
recommended. The guidelines do not do this. The guidelines
instead use a tick box to suggest that the user can ignore the
evidence and use all the techniques for house dust mite
avoidance which have just been reviewed and shown to be
ineffective.
There are other confusing statements. There is a comment in the
section on dosing of inhaled short acting beta 2 agonists which
refers to
“>10-12 puffs per day as a marker of poorly controlled
asthma.”
Surely this is an understatement. The previous BTS
guidelines, the American Thoracic Society Guidelines and
Consensus international guidelines have used doses of greater
than 1 puff a day as a sign of poor asthma control. The inference
being that 1 or more puffs a day should lead to a stepping up of
treatment. Are the new guidelines suggesting that we step up only
when patients are using >10-12 puffs of beta 2 agonist a day?
Finally intravenous aminophylline is removed from the routine
management of acute severe asthma and replaced by
magnesium. Aminophylline will never do well in any evidence
based guidelines as the studies are old, usually underpowered
and poorly designed. The guidelines methodology permits a
“tick box”
to represent
“recommended best practice based on the clinical experience of the guideline development group”.
Why
could intravenous aminophylline not have received such a
commendation? It is hard to find a GP or consultant who can not
remember using aminophylline with good effect. Clearly this is
anecdote but is a good example of “recommended best practice
based on the clinical experience of” doctors who look after patients
with acute severe asthma. I feel very unhappy about this change
and will hesitate before recommending that our hospital adopt the
new management charts for acute severe asthma as set out in
Annex 2 of the guidelines.
Dear Editor
We would like to comment on strength of conclusions of the recent publication by Dr Brusasco et al,[1] particularly that no consideration is given to how the results compare to the balance of evidence that exists.
The paper’s conclusions imply superior efficacy of tiotropium over salmeterol in patients with COPD by emphasising endpoints in which tiotropium shows a difference compar...
Dear Editor
With great interest, we read the guidelines for the management of suspected acute pulmonary embolism (PE) by the British Thoracic Society (June issue 2003).[1] In the discussion of treatment options, the guidelines state that surgical embolectomy should only be considered in cases with absolute contraindications to thrombolysis, which is rarely an important consideration in a life-threatening situat...
Dear Editor
One of the paradoxes of modern medicine is the rapid growing incidence of immune-based diseases over the last half of the century.
Despite enormous advances in our understanding of the immune system, and our ability to manipulate immunity in experienced animals and man, we have not been able to curtail these diseases. In fact, it is becoming increasing evident that immune hypersensitivity response...
Dear Editor
The efficacy and clinical effectiveness of homeopathy engenders considerable debate; it is therefore essential that clinical trials are accurately interpreted and reported. The recent publication by White et al.[1] has highlighted this issue.
The study, assessing classical homeopathy as an adjunctive treatment for childhood asthma concluded that, based on the primary outcome (the active qua...
Dear Editor
Dr Leckridge[1] is correct to state that the children in the study had mild to moderate symptoms of asthma at the time of recruitment. Children with more severe symptoms were excluded at the request of the Ethics Committee, because of the risks that could arise if they stopped their conventional medication. Our study tested homeopathy as an adjunct to standard medical management, not an alternative.
...Dear Editor
This study of quality of life in children with asthma treated with homeopathy is fatally flawed.[1] The Childhood Asthma Quality of Life instrument used was validated in a study by French et al.[2] The children entered into White’s study had scores consistent with those of normal children who don’t have asthma. For a statistically significant improvement to occur in this score, the treated group wo...
Dear Editor
It is indeed a pity that there was no comparison between continuous aminophylline and continuous salbutamol. The authors did not make it very clear why they did not choose this option. The conclusion that there is some favourable outcome with aminophylline is therefore, in my opinion, too strong for the data they present. Another query is: Why did the authors use aminophylline, instead of theofylline, wit...
Dear Editor
We thank Dr Chanarin for his interest in the new Asthma Guideline. We will answer the points made in the order in which he raises them.
1. The quoted studies on breast-feeding appear to be equivocal in terms of the protective effect on asthma, but both show protection against wheezing illness in the first years of life. The recommendation in the guideline specifies such wheezing illne...
Dear Editor
I read with interest the article of Tate et al. indicating that exhaled condensates are acidic in patients with CF and become more acidic during exacerbations. The data show differences in mean values (with some overlap) and the hypothesis that the airways are acidic in these patients seems plausible. However I am concerned that the condensate measurements cannot give a reliable estimate of airway...
Dear Editor
The New Guidelines use evidence based methodology extensively. This methodology has been developed by the Scottish Intercollegiate Guidelines Network and is not only well respected but has been widely applied to develop other guidelines. The guidelines use levels of evidence, I quote
“Level A is: At least one meta analysis, systematic review, or RCT rated as 1++ and directly applicab...
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