The study researchers, led by Dr. Rupert Payne of the Cambridge Centre for Health Services Research in the UK, say that their findings suggest a need for doctors to take "more sophisticated approaches" when prescribing medications to patients.
The incidence of polypharmacy is growing, according to the investigators, mainly because the number of elderly people is increasing and more people are being diagnosed with multiple illnesses.
However, the researchers note that increasing numbers of prescribed medications have been associated with a series of adverse health outcomes.
"These include high-risk prescribing, adverse drug reactions and death. Excessive numbers of medicines may contribute to poorer medication adherence, as well as being associated with lower quality of life," the study authors write.
To determine how pharmacology impacts the risk for hospital admission, the research team analyzed Scottish National Health Service (NHS) primary care data for 180,815 adults aged 20 years or older who had long-term medical conditions.
They assessed the number of medications each person was receiving and linked this to the number of times each patient was admitted to a hospital the following year.