Objectives: To compare different instruments for the assessment of anticholinergic (ACH) drug burden and to assess the association of the aggregate ACH drug burden with the occurrence of delirium in a cohort of elderly orthopaedic surgical patients. Design and methods: 397 patients admitted for acute or elective hip surgery were included in this nested case-control study. Medication use at admission was assessed and each drug was assigned an anticholinergic score using six different instruments. For each patient the aggregate anticholinergic burden from medication was quantified by summing the scores of the drugs used. The association between the anticholinergic burden and the occurrence of delirium was assessed using logistic regression analysis. Results: The final population consisted of 397 patients and delirium occurred in 68 patients (17%). The 397 patients used 185 different drugs at admission date. Each of the six instruments compiles a different number of drugs classified with any anticholinergic properties. The number of patients with any anticholinergic burden varied per instrument in the range from 9% to 80%. There was no instrument which showed a significant association between patients with any anticholinergic burden and the occurrence of delirium [adjusted odds ratio between 1.30 (95% confidence interval 0.54-3.15) and 0.65 (95% confidence interval 0.36-1.16)]. Conclusion: Comparing the different assessment instruments for anticholinergic scores, we found no correlation between any of the instruments. No single instrument can be used as an independent risk factor to predict or to prevent delirium caused by the use of anticholinergic drugs.
|Number of pages||5|
|Publication status||Published - 1 Oct 2009|