People experiencing signs of illness are quick to reach out for a bottle of antibiotics prescribed by their doctor, but a new study shows that nearly 50 million antibiotic prescriptions given out every year are either unnecessary or just plain wrong.

The study, published in the journal JAMA, revealed that out of 154 million patients prescribed with antibiotics every year, 47 million of those, about 30 percent, are unnecessary.

For the study, researchers analyzed data on antibiotic prescriptions written from the 2010-2011 National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey.

Out of the 184 032 sampled visits, 12.6 percent resulted to a prescription of antibiotics.

According to the report from NBC News, patients with acute respiratory conditions such as sinus infections, middle ear infections, sore throats, colds, bronchitis, bronchiolitis, asthma, allergies, influenza, and viral pneumonia have the highest percentage of prescription antibiotics.

Among those, sinus infection has the most antibiotic prescriptions per 1000 population, 56 out of 1000, followed by suppurative otitis media with 47 and pharyngitis with 43 antibiotic prescriptions.

In order to know if the antibiotic prescriptions given to outpatients are necessary, the researchers looked at national guidelines of appropriate levels antibiotic prescribing by age group. If by chance, the national guidelines do not apply to certain diagnosis, the researchers use the region with lowest prescriptions rate of antibiotics as baseline, according to CBS News.

On the other hand, antibiotic prescriptions are defined as inappropriate in the instances when antibiotics were prescribed for an illness that cannot be treated by it.

The researchers then found out that across all conditions, 30 percent of antibiotic prescriptions were inappropriate from 2010 to 2011, which means out of the 506 per 100 population given with antibiotic prescriptions, only 353 were likely appropriate.

These results suggest that about 47 million of antibiotic prescriptions written every year in the United States were most likely to be unnecessary or wrong.