A joint study by the Universities of Lucerne and Zurich and the University Hospital Zurich and Swissmedic shows for the first time comprehensively how many people in Switzerland were admitted to hospital due to medication side effects. Despite the legal obligation, only a small proportion of these were reported in the eight-year observation center period.
Adverse drug reactions can cause discomfort or illness, necessitating hospitalization or, in extreme cases, death. In Switzerland, medical personnel are required to report such cases of adverse drug reactions to Swissmedic, the Swiss regulatory and supervisory authority for medicinal products.
First national study
A study led by Patrick Beeler , head of research at the Center for Family Medicine and Community Care at the University of Lucerne, examined for an eight-year period (2012 to 2019) how many hospitalizations in Switzerland were due to adverse drug events and how many were fatal. Little was previously known about this at the national level. The study also examined how many notifications in this context were received by Swissmedic during the same period. For this purpose, data from the Federal Statistical Office and Swissmedic were analyzed.
Around 32,000 hospital admissions per year
Of approximately 11.2 million hospitalizations during the study period, 256,550 (2.3%) were due to adverse drug reactions. This corresponds to about 32,000 hospital admissions per year. The most common adverse drug reactions were related to the digestive system (e.g., gastrointestinal inflammation), the genitourinary system (e.g., acute renal failure), or mental/behavioral health (e.g., opioid dependence). For cases attributable to medication side effects, hospital mortality was 2.2% (5669). During the period studied, Swissmedic received reports of 14,109 hospitalizations and 700 deaths. The reporting rate in the study is thus estimated at 5% and 12%, respectively.
Few cases are reported
The reporting rates appear low compared to the total number of hospitalizations. In an international comparison, they are in the upper range according to available figures, explains study leader Patrick Beeler. The international scientific literature assumes a reporting rate of 0.6% to 4.7% of hospital admissions due to adverse drug reactions. No international comparative figures are available for hospital mortality. According to Beeler, the quality of Swiss reports is very good in international comparison.
When asked about the reasons for the low reporting rates, the study director refers to a survey from Germany that identifies several causes: Ignorance about the reporting obligation, effort, uncertainty regarding the reporting system or the organization behind it, concerns about data protection, fear of legal consequences, and a lack of incentives. However, sanctions as a negative incentive to comply with the reporting obligation would not work, Beeler explains: "Since side effects are not systematically recorded at the patient level, it is hardly possible to compare them with the reports received. Therefore, reporting failures are usually not known.
Cornerstone of drug safety
In order to improve the existing situation, the obligation to notify should be adequately addressed in the training of healthcare professionals and reminded regularly later on, Beeler recommends. It is important to understand the importance of so-called spontaneous reports for patient safety. Despite other available data sources, these represent the most important pillar of drug safety, through which most previously unknown or inadequately described risks are also discovered, Beeler explains. It would be particularly important to report cases of patients rarely considered in clinical trials, such as infants, Beeler added.
Data situation still leaves much to be desired
Although data are now available on the extent of certain drug-related problems in Switzerland and on the patients affected, Beeler explains, there are also major data gaps. However, there are also major data gaps. For example, there is no link between individual patients and the medications prescribed for outpatients. Such a link would allow informative evaluations, as they are already being carried out in some Scandinavian countries, says the study leader.
Patrick E. Beeler, Thomas Stammschulte, Holger Dressel
Hospitalizations Related to Adverse Drug Reactions in Switzerland in 2012-2019: Characteristics, In-Hospital Mortality, and Spontaneous Reporting Rate
Drug Safety, 2023