Potentially Inappropriate Medications Pre- and Post-Diagnosis of Major Neurocognitive Disorders Among Older People in Sweden: A Register-Based, 6-Year Longitudinal Study

OBJECTIVE: The aim of the present study was to investigate how potentially inappropriate medication usage and anti-dementia drug use change from 3 years prior to, up until 3 years post-diagnosis of major neurocognitive disorders among older people living in Sweden. METHODS: People registered in the Swedish registry for cognitive/dementia disorders from 1 July, 2008 to 31 December, 2017, and aged 68 years or older at diagnosis, were included (n = 67,226). Data were combined with the Swedish Prescribed Drug Registry to obtain information about drugs collected in 6-month periods at Swedish pharmacies from 3 years pre-diagnosis until 3 years post-diagnosis. Potentially inappropriate medications were identified according to Swedish national guidelines. A generalised estimating equation regression model and estimated marginal means were used. RESULTS: Of the 67,226 people included in the study population, 59.2% were women and the mean age ± standard deviation was 81.5 ± 6.4 years, 47.0% lived together with a spouse or partner, and 88.9% were living at home at the time of diagnosis. The proportions of people using potentially inappropriate medications continuously decreased pre- and post-diagnosis, except for antipsychotic drug use, which continuously increased both pre- and post-diagnosis. Moreover, anticholinergic drug use increased pre-diagnosis and declined post-diagnosis. When comparing the periods pre- and post-diagnosis date, the adjusted proportion of people using potentially inappropriate medications was significantly lower post-diagnosis compared with pre-diagnosis, except for the adjusted proportion using antipsychotics, which was significantly higher post-diagnosis, 10.6%, compared with the period before, 3.1% (adjusted odds ratio 3.71; 95% confidence interval 3.59–3.83). The adjusted proportion of people using anticholinergic drugs was significantly lower post-diagnosis, 7.2%, compared with the pre-diagnosis period, 8.9% (adjusted odds ratio 0.80; 95% confidence interval 0.78–0.82). Anti-dementia drug use was significantly higher post-diagnosis, 52.6%, when compared with the pre-diagnosis period, 3.5% (adjusted odds ratio 30.13; 95% confidence interval 29.19–31.10). CONCLUSIONS: Overall, the prevalence of people using potentially inappropriate medications decreased and was significantly lower post-diagnosis of major neurocognitive disorders, except for antipsychotics. This indicates that potentially inappropriate medication use should be noticed and reviewed among all older people. The small decrease in the prevalence of anticholinergic drug users and the increasing proportions of people using antipsychotic drugs post-diagnosis are of special concern because of the adverse drug reactions associated with these types of potentially inappropriate medications. Consequently, it is important to identify and regularly question anticholinergic and antipsychotic drug treatment to prevent unnecessary and serious adverse drug reactions among a vulnerable group of people.