Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Simple test guides antibiotic prescriptions in primary care

25.02.2010
A simple lab test can help primary care physicians decide which patients suffering from a respiratory tract infection will benefit from a course of antibiotics.

The study published ahead of print in the European Respiratory Journal, the European Respiratory Society's peer-reviewed publication, has found that including a new diagnostic marker in a therapeutic strategy reduces antibiotic prescription rates by more than 40%.

Until now, deciding whether antibiotics are needed for treating a respiratory tract infection has seemed to be more art than science: for evidence of this, one only has to look at the vast differences in prescribing habits of doctors around Europe.

Respiratory infections are extremely common. Doctors are taught to prescribe antibiotics on the basis of clinical features such as pus in the sputum or high fever, which point to the presence of a bacterial pathogen. However, basing this decision on clinical judgment alone is not always easy. Additional lab tests for markers such as C-reactive protein may help to distinguish between a viral and a bacterial infection.

Antibiotic prescriptions not only impose a burden on healthcare resources but, more importantly, contribute to the worldwide problem of antimicrobial resistance. Varying patterns of antibiotic resistance around Europe are strongly linked to differing prescription habits in general practice. Standardised strategies to help reduce antibiotic misuse are desperately needed.

A relatively new marker of bacterial infections, procalcitonin (PCT), may enrich the diagnostic tools of primary care physicians and become a useful part of the decision process.

PCT is a precursor of the hormone calcitonin, which, along with parathyroid hormone, regulates the calcium and phosphate balance in the body. In healthy people, concentrations of PCT are low, since it is produced only in the thyroid gland and is promptly converted to the mature hormone. In the presence of a bacterial infection, however, PCT is produced by nearly all cell systems and released into the blood circulation. It can be found in high concentrations as early as 3 hours after a bacterial infection, reaching maximum levels after 6-12 hours. In people with viral infections, in contrast, PCT levels increase only marginally or not at all.

To fill or not to fill?

The two-part study included patients diagnosed with an acute respiratory tract infection either upper (e.g. sinusitis, middle ear infection) or lower (e.g. bronchitis or pneumonia). In part 1, researchers documented antibiotic prescription rates, values for blood PCT and the outcome of 702 patients presenting with a respiratory infection to 45 primary care physicians.

In Part 2, researchers compared standard care with a PCT-guided antimicrobial treatment in 550 patients. Patients who were in need of antimicrobial treatment according to the clinical judgment of their general practitioner received a prescription but were asked not to fill it until they were told to do so by phone. The doctors were free to choose the type and dosage of antibiotics.
Antibiotics were recommended for patients with PCT levels over 0.25 ng/mL, a threshold below which a bacterial infection is unlikely. However, primary care physicians were allowed to over-rule the recommendation for clinical reasons. Only one blood sample was required for the measurement of PCT levels.

Patients whose PCT levels did not indicate the need for antibiotic treatment were asked to return the prescription.

Patients were followed up with structured telephone interviews by blinded investigators after 2 weeks and again after 4 weeks. They were asked whether their respiratory tract infection symptoms had persisted, whether their infection impaired their everyday life or leisure activities, and whether they needed to visit the doctor again or needed new or additional antibiotic treatment. They were also questioned about the duration of their treatment, any adverse effects and the possible need for hospitalisation.

According to principal investigator Professor Tobias Welte, head of the Department of Respiratory Medicine at Hannover Medical School (Germany), in daily practice, one in three patients receives an antibiotic for a respiratory infection: "We wanted to show that this number can be cut in half."

After initial clinical evaluation, 84 patients (30.5%) were assigned to antibiotics in the PCT group and 89 patients (32.4%) in the control group (p = 0.701). After PCT levels had been determined, only 21.5% in the PCT-guided group received antibiotics (41.6% reduction). These numbers include 36 patients whose PCT results were over-ruled by clinicians.

Despite the significant difference in antibiotic prescriptions between the two groups, patients did not show any difference in the number of days they were affected by their disease (mean 9.04 days for the PCT-guided group versus 9.00 for the control group, difference 0.04, 95% confidence interval -0.73 - 0.81). There was no significant difference in the outcome between the PCT group that proceeded as advised, the PCT group for which doctors overruled the lab result, and the control group (9.008 versus 9.250 versus 9.000 days, p = 0.9605).

"There is huge potential for further reduction of antibiotic treatment," comments Professor Welte. "A simple PCT-guided strategy of decisions on antibiotic treatment including the option of clinical over-ruling not only reduces the antibiotic treatment rate by 41.6% but is just as safe for patients."

The strength of the PCT-guided strategy is its ability to predict which patients are in need of antibiotics (and which can safely be treated without).

"An important issue is to allow for clinical over-ruling when applying PCT-guided strategies. Although over-ruling was observed in only a minority of patients (13% in our study), doctors would not feel comfortable without this option when caring for their patients."

"We conclude that a PCT-guided strategy applied in primary care in unselected patients presenting with symptoms of acute respiratory infection reduces antibiotic use by 41.6% without compromising patient outcome. The treatment algorithm and measurement procedure are simple enough to be applied even in routine settings."

Disclosures:
Prof. Welte has received research grants and fees for lectures from BRAHMS AG, the manufacturer of the lab test.
Contact: (For journalists' personal use only, not for publication)
Prof. Dr. Tobias Welte
Tel.: +49-511-532-3531
Fax: +49-511-532-3353
E-Mail: welte.tobias@mh-hannover.de
Title of the original article: "A simple procalcitonin-guided strategy results in safe reductions of antibiotic use in patients with symptoms of acute respiratory tract infections in primary care."

Dr. Anka Stegmeier-Petroianu | idw
Further information:
http://www.mh-hannover.de

More articles from Health and Medicine:

nachricht New High-Performance Center Translational Medical Engineering
26.04.2017 | Fraunhofer ITEM

nachricht A promising target for kidney fibrosis
21.04.2017 | Brigham and Women's Hospital

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>