Lars Peter Nielsen


Medication errors and patient safetyA group doing research on prevention of medication errors in patients has developed during recent years at the Center for Pharmacotherapy, Institute of Biomedicine. The group has been focusing development of a consensual definition of medication errors, quantification studies on the problem as well as interventional studies.

Errors associated with drug therapy seem particularly frequent, especially in sector transitions. The vast majority of errors are of no clinical relevance, while less than 10 percent have been shown to cause harm to patients in terms of death and increased morbidity. As drug consumption is high, particularly among the elderly, it must be assumed that even a modest risk of serious medication errors could lead to a large number of injuries with the consequence of added costs due to prolonged hospitalization and additional treatment. We have performed several studies demonstrating that medication errors are a problem in Danish hospitals. However, there has been no unambiguous evidence for the effect of medication review on length of hospital stay, readmissions and death. One possible reason could be that all patients have undergone the same intervention despite the complexity of their drug therapy. It is known that the risk of clinically significant errors is related to both patient factors such as age and comorbidity, and to drugs used in each individual, e.g. number of drugs and their potential toxicity. This has led to a current major study of individual risk stratification for patients (see below).

Allergic and Obstructive Airways Diseases
These diseases, ie. allergic rhinitis, asthma and COPD, inflict approximately one third of the population in Western countries, and have as such a major impact individually as well as societal.

The research has been carried out in close collaboration with the Research Department of Respiratory Diseases, Aarhus University Hospital. Our research considers disease mechanisms, as well as observational and intervention studies.

So far, a major topic has been the description of eosinophils and their markers during allergic mucosal inflammation in rhinitis and asthma. The impact of pharmacologic interventions on eosinophils and their markers has been studied, as well. We have demonstrated an eosinophil marker in serum, ie. ECP, as a prognostic indicator for asthma development in allergic rhinitis patients. Likewise, we have studied applicability of eosinophil markers and exhaled NO as monitoring parameters in allergic rhinitis and asthma.

In addition to numerous studies on pharmacologic interventions at phases II-IV of drug development, the group has undertaken studies on treatment of asthma and COPD with magnesium, vitamin D and various alternative therapies.

Research interests

The aim of the project is to develop, validate and document the effect of an objective and easily applicable algorithm, that can stratify patient risk of injury caused by medication errors and, hence, determine the level of intervention needed in drug therapy. In the long term, the aim is to integrate the algorithm into existing IT systems, to generate risk scores automatically. This will lead to increased patient safety and optimize drug treatment as well as ressource utilization in the hospital sector. 

The project includes the following stages: 

  • Development of algorithm (risk factors, intervention possibilities and scoring system) 
  • Validation of the algorithm (test on a standardized population and pilot study) 
  • Documentation of the algorithm (prospective, randomized, controlled trial)
  • Health economic evaluation of interventional impact based upon the algorithm
  • Improving applicability of medication reviews based on the algorithm (questionnaire study)
  • Mechanisms of allergic airway inflammation with particular reference to the eosinophil granulocyte and
  • Monitoring/pharmacologic intervention studies of allergic rhinitis, asthma and COPD.


  • Consensus studies on development of common definitions
    Validating studies on methods for measuring medication errors
    Quantitative studies on medication errors
    Randomised controlled studies on interventional effects towards medication errors
  • Multicolor FACS analysis
    FEIA analysis of eosinophil granule proteins
    Exhaled NO
    Acoustic Rhinometry
    Nasal lavage and biopsy techniques
    Allergen and non-allergen challenge techniques
    Measurement techniques for lung function 
    Randomised controlled interventional studies

Collaborators and centres

Department of Clinical Pharmacology, Aarhus University Hospital,The Hospital Pharmacy Aarhus, Professor, PhD, Chief Physician Jan Mainz, Department of Psychiatry, Aalborg University Hospital, Ass. Professor, DMSc,  Chief Physician Troels Krarup Hansen, Department of Emergency Medicine, Aarhus University Hospital, PhD-student Ann Lykkegaard Sørensen, MHSc,  Department of Psychiatry, Aalborg University Hospital

Christer Peterson, Associate Professor, Department of Medical Biochemistry, Uppsala University

Research group members

Group members at the Aarhus University Hospital:

  • Ronald Dahl, Professor, DMSc, Chief Physician
  • Lars Peter Nielsen, Associate Professor, Chief Physician
  • Hans Jürgen Hoffmann, Associate Professor, PhD
  • Mette K. B. Dolberg, PhD-student
  • Ayfer Topcu, PhD-student
  • One research year student

Group leader

Lars Peter Nielsen

Associate professor


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