Asthma Treatment Claims May Mislead As Drug Trials Open To Industry Manipulation
Dr Ike Iheanacho, editor of DTB said:
"Clinical trials vary greatly in the types of measures they use to assess the effects of asthma drugs, and this makes it difficult to compare different trials or to assess whether new treatments offer a genuine benefit for patients."
There are many potential outcomes or endpoints to choose from when designing trials to look at effectiveness of a particular drug, and DTB believes this can lead to confusion.
The lack of agreed benchmarks to test asthma drugs in trials means that endpoints chosen might have little to do with how well the drug performs compared to other treatments; instead, the choice might be influenced more by the promotional objectives of the drug company.
Dr Iheanacho explains:
"A trial may, for example, define an endpoint as the change in asthma symptoms such as cough, wheeze and breathlessness and measure these during the day and night.
"The symptoms can be assessed in terms of severity and frequency, but there is no universally accepted standard for scoring them, and different studies record different sets of symptoms and use different scales."
Likewise, lung function measures on their own can be an inadequate or misleading measure of treatment effect and so need to be considered with other outcomes such as symptoms, exacerbations or quality of life.
Different endpoints do not necessarily correlate with each other. Interpreting and comparing data from different trials can therefore be difficult.
Dr Iheanacho concludes:
"It is also important to beware of the potential for over interpretation of the secondary results of a trial: these may just add to the confusion about what is actually being measured and the drug's true effectiveness."
1 Exacerbations are associated with major morbidity, lifestyle disruption, hospital admission, increased cost of care and risk of death. However there is no agreed definition of a mild, moderate or severe exacerbation, and there is a wide variation in the definitions used in trials.
2 Recorded or recalled use of inhaled short acting beta2 agonists is often used as a marker of asthma control. But some patients habitually take two puffs of bronchodilator before using an inhaled corticosteroid, and some use a bronchodilator before exercise to prevent symptoms. Such use must be distinguished from use of a bronchodilator for acute symptom relief.
3 For over 40 years Drug and Therapeutics Bulletin (DTB) has provided rigorous and independent evaluations of, and practical advice on, individual treatments and the management of disease for doctors, pharmacists and other healthcare professionals.
4 DTB also produces Treatment Notes - award-winning, evidence-based, practical information for patients that complements that available to healthcare professionals.
5 For further information about DTB and Treatment Notes or to subscribe, please go to www.dtb.org.uk
6 Annual subscription £49. Retired doctors, pharmacists and students £24.50. All orders to DTB, Which? Castelmead, Gascoyne Way, Hertford X, SG14 1LH
Which?
2 Marylebone Road
London
NW1 4DF
http://www.which.co.uk
T: 020 7770 7562
F: 020 7770 7666
Make your money talk at
which.co.uk/moneytalk
Astm Tratamentul Creanþe mai inducã în eroare Ca Drug Procesele deschis Industrie manipulare - Asthma Treatment Claims May Mislead As Drug Trials Open To Industry Manipulation - articole medicale engleza - startsanatate