Anticholinergic medicine burden and older patients

Anticholinergic medicines are commonly used to treat e.g. incontinence. These medicines have side effects, which may cause and also exacerbate e.g. dryness of the mouth, increased heart rate, and even cognitive impairment. Older people may be more at risk for these side effects as they may be experiencing similar symptoms as a natural effect of aging, and because they may be using several medicines causing these effects. Older people often have a high medicine burden and also a high disease burden. Measuring anticholinergic effects to change medicine regimens and to reduce the symptoms is difficult as there is no golden standard method. This thesis investigated the published methods available for estimating anticholinergic burden in the literature review part, and used one anticholinergic scoring system, the Anticholinergic Risk Scale, in a cross-sectional study to test the effects of anticholinergics on mortality in 1004 older institutionalised patients from Helsinki area public hospitals. Cross-tabulations and Kruskal-Wallis or Chi square methods were used to detect differences between variables such as nutritional status or certain diagnoses when the patients were stratified according to their anticholinergic use. Cox Proportional Hazard regression, the logrank test and Kaplan-Meier curve were used to investigate the effects of anticholinergics on 5-year all-cause mortality. An in vitro serum assay and seven anticholinergic scoring systems were identified in the literature search. Also, 17 anticholinergic lists were identified, which covered 278 medicines, of which 21 appeared on at least eight of the lists. In the empirical study, the women's (n = 745) mean (± SD) age was 83.35 (± 9.99) years, and they were older than the men (n = 241, mean age ± SD 75.11 ± 11.48, p < 0.001). The 1004 patients (response rate 70 %) were using a mean (± SD) number of 7.1 ± 3.4 regular medicines (range 0-20). 455 patients used no anticholinergics, 363 had some anticholinergic burden (score 1 or 2), and 186 had a high burden, with anticholinergic scores of 3 or more. The mean ARS score (± SD) was 1.2 ± 1.5 (range 0-10). When three anticholinergic lists were compared, all three lists identified only 280/791 of patients who were anticholinergic users according to at least one list. No association was found between anticholinergic medicine use and mortality. There are several methods available for measuring anticholinergic burden, but there is a need for a consensus method. This was highlighted by the lack of agreement on medicines on different lists and when three anticholinergic lists tested identified different patients when compared to each other. Anticholinergic use was common in this frail, older patient sample, but no effect on mortality was shown in this study setting. The cross-sectional nature of the data limits the reliability of the study, and any conclusions beyond older patients in Helsinki area must be done very cautiously. Future research should define anticholinergics better and investigate their possible effect on mortality in a prospective, randomised, and controlled setting.