Anticholinergic Component of the Drug Burden Index and the Anticholinergic Drug Scale as Measures of Anticholinergic Exposure in Older People in New Zealand: A Population-Level Study

Assessing the feasibility of anticholinergic burden scales and measures in administrative data: A systematic review

AIM

This systematic review aimed to identify and evaluate the quality and adaptability of existing anticholinergic burden scales and measures by using administrative dispensing data.

METHOD

A comprehensive literature search was conducted using the Medline, Embase, CINAHL, and Google Scholar databases from 2001 to 2022. Studies that introduced, updated, or modified anticholinergic burden scales and measures were included in this review. Quality assessment considered various aspects, including scoring systems, tool development criteria, and specific requirements tailored for administrative data.

RESULTS

Twenty-eight anticholinergic burden scales and measures were identified in 14 countries. The Modified Anticholinergic Risk Scale excelled in the scoring system, while the German Anticholinergic Burden Scale stood out in the scale development process. However, significant variability was observed in methodologies, medication listings, and adaptability to administrative data. Quality assessment considers aspects such as potency, dose, exposure duration, longitudinal measurement, clinical interpretation, and compatibility with administrative data variables. The evaluation also considered tool development criteria including evidence for medication selection, panel expertise, relevance, updating methods, international applicability, validation, and clinical guidance.

CONCLUSION

This review emphasizes the importance of adaptable and robust tools that can work well with administrative data to ensure patient safety and better health outcomes, given the ongoing evolution of anticholinergic medications. The findings of this systematic review provide valuable insights for clinicians and researchers in selecting the most appropriate anticholinergic burden scale or measure according to their specific needs and data sources. This systematic review was registered with PROSPERO (registration ID CRD42023423959).

Anticholinergic Burden and Xerostomia in Critical Care Settings

BACKGROUND

Although previous studies have established the association of medications with anticholinergic adverse effects and xerostomia, anticholinergic burden and xerostomia in critical care settings are poorly characterized. The objective of this study was to determine the impact of medication burdens associated with anticholinergic adverse effects, particularly the occurrence of xerostomia (dry mouth) in a critical care setting. In addition, this study explored the correlation between the timing of the first instance of xerostomia and the administration timing of medication known to have anticholinergic adverse effects.

METHODS

A retrospective case-control study was used with the MIMIC (Medical Information Mart for Intensive Care) III database. The MIMIC-III clinical database is a publicly available, deidentified, health-related database with more than 40 000 patients in critical care units from 2001 to 2012. Cases of xerostomia (n = 1344) were selected from clinical notes reporting "dry mouth," "xerostomia," or evidence of pharmacological treatment for xerostomia; control (n = 4032) was selected using the propensity analysis with 1:3 matching on covariates (eg, age, sex, race, ethnicity, and length of stay). The anticholinergic burden was quantified as the cumulative effect of anticholinergic activities using the Anticholinergic Burden Scale.

RESULTS

Anticholinergic burden significantly differed between xerostomia patients and control subjects (P = .04). The length of stay was a statistically significant factor in xerostomia. The probability of developing the symptom of xerostomia within 24 hours was .95 (95%) for patients of xerostomia.

CONCLUSIONS

Anticholinergic Burden Scale is associated with xerostomia in the critical care setting, particularly within 24 hours after admission. It is crucial to carefully evaluate alternative options for medications that may have potential anticholinergic adverse effects. This evaluation should include assessing the balance between the benefits and harms, considering the probability of withdrawal reactions, and prioritizing deprescribing whenever feasible within the initial 24-hour period.

Anticholinergic burden in older adults with psychiatric illnesses: A cross-sectional study

OBJECTIVES

We aimed in this study to determine the extent of exposure to anticholinergic drugs in older adults with psychiatric illnesses using the anticholinergic cognitive burden (ACB) scale and to identify the factors associated with anticholinergic drugs use and higher ACB scores.

METHODS

A cross-sectional study was conducted in the psychogeriatric division of an elderly care hospital. The study sample comprised all inpatients, aged ≥65 years, and diagnosed with psychiatric illness.

RESULTS

Anticholinergic drugs use was reported in 117 (79.6 %) patients, 76 (51.7 %) had an ACB score ≥ 3. Schizophrenia [OR = 5.4 (95 % CI 1.1-10.2), p = 0.02], anemia [OR = 2.2 (95 % CI 1.54-7.89), p = 0.01], and anticholinergic adverse effects [OR = 2.8 (95 % CI 1.12-7.07), p = 0.04] were significantly associated with a higher likelihood of using anticholinergic drugs. The odds of having an ACB score ≥ 3 over an ACB score = 0 were significantly increased by schizophrenia [OR = 4.9 (95 % CI 1.65-8.02), p = 0.01], anemia [OR = 1.32 (95 % CI 1.90-6.90), p = 0.02], and polypharmacy [OR = 1.74 (95 % CI 1.10-2.40), p = 0.04], while they were significantly decreased by age [OR = 0.86 (95 % CI 0.78-0.96), p < 0.001]. Patients with cognitive impairment were less likely than those without cognitive impairment to have an ACB score ≥ 3 over an ACB score = 0.

CONCLUSIONS

Our study revealed that older adults with psychiatric illnesses were exposed to high anticholinergic burden.

Impact of a Comprehensive Intervention Bundle Including the Drug Burden Index on Deprescribing Anticholinergic and Sedative Drugs in Older Acute Inpatients: A Non-randomised Controlled Before-and-After Pilot Study

INTRODUCTION

Implementation of the Drug Burden Index (DBI) as a risk assessment tool in clinical practice may facilitate deprescribing.

OBJECTIVE

The purpose of this study is to evaluate how a comprehensive intervention bundle using the DBI impacts (i) the proportion of older inpatients with at least one DBI-contributing medication stopped or dose reduced on discharge, compared with admission; and (ii) the changes in deprescribing of different DBI-contributing medication classes during hospitalisation.

METHODS

This before-and-after study was conducted in an Australian metropolitan tertiary referral hospital. Patients aged ≥ 75 years admitted to the acute aged care service for ≥ 48 h from December 2020 to October 2021 and prescribed DBI-contributing medication were included. During the control period, usual care was provided. During the intervention, access to the intervention bundle was added, including a clinician interface displaying DBI score in the electronic medical record. In a subsequent 'stewardship' period, a stewardship pharmacist used the bundle to provide clinicians with patient-specific recommendations on deprescribing of DBI-contributing medications.

RESULTS

Overall, 457 hospitalisations were included. The proportion of patients with at least one DBI-contributing medication stopped/reduced on discharge increased from 29.9% (control period) to 37.5% [intervention; adjusted risk difference (aRD) 6.5%, 95% confidence intervals (CI) -3.2 to 17.5%] and 43.1% (stewardship; aRD 12.1%, 95% CI 1.0-24.0%). The proportion of opioid prescriptions stopped/reduced rose from 17.9% during control to 45.7% during stewardship (p = 0.04).

CONCLUSION

Integrating a comprehensive intervention bundle and accompanying stewardship program is a promising strategy to facilitate deprescribing of sedative and anticholinergic medications in older inpatients.

Anti-Cholinergic Drug Burden Among Ambulatory Elderly Patients in a Nigerian Tertiary Healthcare Facility

Background: The use of drugs with anticholinergic effects among elderly patients is associated with adverse clinical outcomes. There is paucity of information about anticholinergic drug burden among Nigerian elderly population. Objectives: To determine the anticholinergic drug burden among elderly Nigerian patients. Methods: This was a retrospective cross-sectional study conducted among elderly patients (aged 65 and above) who visited the Family Medicine outpatients' clinics of the Ekiti State University Teaching Hospital, Ado-Ekiti, Nigeria between July 1 and October 31, 2018. Information extracted from the case files included patient's age, sex, diagnoses, and list of prescribed medications. Medicines with anticholinergic effects were identified and scored using the anticholinergic drug burden calculator (http://www.acbcalc.com). Results: The medical records of 400 patients were analyzed with females accounting for 60.5% of the study population. The mean age of participants was 73 ± 7.4 years with only 28 (7%) of patients having more than two co-morbid conditions. Polypharmacy was identified in 152 (38%) of the patients while 147 (36.7%) had drugs with anticholinergic effects prescribed. The anticholinergic burden was high in 60 (15%) patients. Polypharmacy was significantly associated with having more than two diagnosed conditions and high anticholinergic burden (p value of < 0 .001 and 0.013 respectively). There was significant correlation between total number of prescribed drugs and count of diagnoses (r = 0.598; p < 0 .000) and between total number of prescribed drugs and number of drugs with anticholinergic effects (r = 0 .196; p < 0 .000). Conclusion: The anticholinergic burden in this group of elderly Nigerian patients was low; majority (67%) had no exposure to drugs with anticholinergic effects with only 15% having high anticholinergic burden. Polypharmacy and multiple diagnosed conditions were positively associated with high anticholinergic burden. Based on the positive and significant correlations found in this study, a reduction in the number of prescribed medicines especially those with significant anticholinergic effects used for secondary indications may lessen the anticholinergic burden among the elderly.

Association between anticholinergic burden and hospital readmission in older patients: a prospective analysis

OBJECTIVE

Despite known adverse effects of anticholinergic (AC) medication, little work has been devoted to the impact of high anticholinergic burden on the rate of hospital readmission. The purpose of this study was to analyze prospectively the link between high AC burden and the rate of all-cause thirty-day hospital readmission in older people.

STUDY DESIGN

This was a prospective non-interventional study conducted from January to August 2019 in one acute-care geriatric ward. All hospital stays of patients aged at least 75 years who were discharged to their home were included in the analysis. AC burden was determined from discharge prescriptions using the Anticholinergic Drug Scale (ADS) and the Anticholinergic Risk Scale (ARS), and defined as high if ≥3.

RESULTS

The analysis concerned 350 hospital stays. Median patient age was 88 years (interquartile interval 84-91). In a multivariate analysis, the risk of hospital readmission within 30 days was not increased for patients with high AC burden (ADS≥3): odds ratio 1.16 [95% confidence interval 0.56-2.37], compared to a patient whose anticholinergic burden was not high.

CONCLUSION

Unlike retrospective studies on this issue, the findings of our prospective analysis do not support a higher risk of hospital admission within 30 days for older people with high AC burden as assessed from their discharge prescriptions.

Relative prevalence of 10 types of pharmacodynamic interactions in psychiatric treatment

OBJECTIVE

To assess the relative prevalence and factors affecting the prescription of medication combinations with a theoretical efficacy limiting pharmacodynamic interaction, defined as two medications with opposing indications and side effects or antagonistic action at the primary receptor of mechanism of action.

METHOD

One hundred sixteen combinations were identified for 10 types of pharmacodynamic interactions. PubMed was searched for each combination to assess the quality of evidence either supporting clinical use or verifying reduced efficacy. Micromedex was searched to determine the presence of warnings to prescribers of reduced efficacy. The prevalence in clinical practice was determined by computer review of the Genoa Healthcare database for all prescribers at 10 participating community mental health centers. The expected prevalence was calculated as the product of the probability of each medication prescribed alone and was compared with the actual prevalence of the combination using the test of proportions.

RESULTS

The frequency of prescription of eight combinations met the Bonferroni corrected level of significance of p < 0.001. Four were combinations of amphetamine and D2 antagonists and each were prescribed less often than chance, p = 0.0001 consistent with epidemiological studies and multiple animal studies verifying an efficacy limiting interaction. Despite epidemiological studies indicating increased risk of accidents, alprazolam and amphetamine were prescribed more often than chance, p = 0.0001. Micromedex generated warnings for efficacy limiting interactions for five other combinations, but with no subsequent change in prescription frequency.

CONCLUSIONS

Neither presence of medical evidence nor warnings from Micromedex consistently affect the prescription of combinations with pharmacodynamic efficacy limiting interactions.

Association of Drug Burden Index with grip strength, timed up and go and Barthel index activities of daily living in older adults with intellectual disabilities: an observational cross-sectional study

BACKGROUND

Drug Burden Index (DBI), a measure of exposure to medications with anticholinergic and sedative activity, has been associated with poorer physical function in older adults in the general population. While extensive study has been conducted on associations between DBI and physical function in older adults in the general population, little is known about associations in older adults with intellectual disabilities (ID). This is the first study which aims to examine the association between DBI score and its two sub-scores, anticholinergic and sedative burden, with two objective measures of physical performance, grip strength and timed up and go, and a measure of dependency, Barthel Index activities of daily living, in older adults with ID.

METHODS

Data from Wave 2 (2013/2014) of the Intellectual Disability Supplement to the Irish Longitudinal Study on Ageing (IDS-TILDA) was analysed. Analysis of Covariance (ANCOVA) was used to detect associations and produce adjusted means for the physical function and dependency measures with respect to categorical DBI scores and the anticholinergic and sedative sub-scores (DBA and DBS).

RESULTS

After adjusting for confounders (age, level of ID, history of falls, comorbidities and number of non-DBI medications, Down syndrome (grip strength only) and gender (timed up and go and Barthel Index)), neither grip strength nor timed up and go were significantly associated with DBI, DBA or DBS score > 0 (p > 0.05). Higher dependency in Barthel Index was associated with DBS exposure (p < 0.001).

CONCLUSIONS

DBI, DBA or DBS scores were not significantly associated with grip strength or timed up and go. This could be as a result of established limitations in physical function in this cohort, long-term exposure to these types of medications or lifelong sedentary lifestyles. Higher dependency in Barthel Index activities of daily living was associated with sedative drug burden, which is an area which can be examined further for review.

Measuring anticholinergic exposure in patients with dementia: A comparative study of nine anticholinergic risk scales

OBJECTIVE

To describe the prevalence and concordance of anticholinergic exposure according to 9 published scales, to quantify the relative weight of the drug subtypes included in each scale, and to identify clinical variables related to anticholinergic exposure.

METHODS

Observational and cross-sectional study using 5323 cases of dementia diagnosed in the 7 hospitals of the public health care system of the Health Region of Girona (Spain) between 2007 and 2014 and registered by the Registry of Dementias of Girona (ReDeGi). We used the Pharmacy database that includes all the drugs prescribed by specialist and primary care physicians and dispensed in pharmacies. We calculated the anticholinergic exposure using the scoring rules of each scale. Age, gender, place of residence, dementia subtype, Clinical Dementia Rating score, Mini-Mental Status Examination score, and Blessed Dementia Rating Score at the moment of dementia diagnose were retrieved from the ReDeGi.

RESULTS

Prevalence of the annual anticholinergic exposure ranged from 36.3% to 69.0% according to the different scales, the concordance among scales was poor to moderate, and the central nervous system drugs accounted the most for anticholinergic exposure. Being in a nursing home, having depressive symptoms, having a non-Alzheimer's dementia subtype, the number of drug treatments, and the severity of dementia were main determinants of anticholinergic exposure.

CONCLUSIONS

There is a large difference in outcomes among the 9 anticholinergic risk scales. Clinicians and researchers should be aware of these differences when using these instruments in patients with dementia.

Potentially Harmful Medication Use and Decline in Health-Related Quality of Life among Community-Dwelling Older Adults

Background

Several scales to quantify the impact of potentially harmful medications (PHMs) have been shown to predict mortality and functional decline; however, the effect of PHMs on quality of life (QoL) has not been well-studied.

Objective

The aims of this study were to investigate an association between PHM use and change in health-related QoL among community-dwelling older adults, and to compare the predictive capacity of PHM scales.

Methods

We conducted a retrospective cohort study using prescription claims data and survey responses. A total of 426 community-dwelling adults aged 65 years or older who visited senior centers and had received prescriptions through a statewide prescription drug subsidy program were included. Anticholinergic Cognitive Burden (ACB), Drug Burden Index-sedative component (DBI-Se), Drug Burden Index-anticholinergic component (DBI-ACh), and the number of regular medications and Beers list medications were calculated from the claims data between baseline and 12 months. In addition, change in the EuroQoL five-dimensions questionnaire (EQ-5D) between baseline and 6- and 12-month follow-up were measured as the main outcome. A linear mixed model was used for the analysis.

Results

After adjusting for covariates, both DBI-Se (coefficients − 0.076, 95% confidence interval [CI] − 0.131 to − 0.020) and DBI-Ach (coefficients − 0.095, 95% CI − 0.188 to − 0.002) significantly predicted a decline in EQ-5D index. The ACB, number of regular medications, and number of Beers medications did not have a significant association with EQ-5D changes.

Conclusions

PHM measures incorporating dose revealed a better predictive capacity for QoL change. Reducing cumulative drug dose, as well as stopping medications, would be important for the well-being of this population.

Electronic supplementary material

The online version of this article (10.1007/s40801-017-0123-8) contains supplementary material, which is available to authorized users.

The effect of comprehensive geriatric assessment on anticholinergic exposure assessed by four ranked anticholinergic lists

BACKGROUND

Older people often use multiple drugs, and some of them have anticholinergic activity. Anticholinergic drugs may cause adverse reactions, and therefore their use should be limited. To identify anticholinergic load, several ranked lists with different drugs and scoring systems have been developed and used widely in research. We investigated, if a comprehensive geriatric assessment (CGA) decreased the anticholinergic drug score in a 4-year period. We used four different anticholinergic ranked lists to determine the anticholinergic score and to describe how the results differ depending on the list used.

METHODS

We analyzed data from population-based intervention study, in which a random sample of 1000 persons aged ≥75 years were randomized to either an intervention group or a control group. Those in the intervention group underwent CGA including medication assessment annually between 2004 and 2007. Current medication use was assessed annually. The anticholinergic load was calculated by using four ranked lists of anticholinergic drugs (Boustani's, Carnahan's, Chew's and Rudolph's) for each person and for each year.

RESULTS

CGA had no statistically significant effect on anticholinergic exposure during the 4-year follow-up, but improvements towards more appropriate medication use were observed especially in the intervention group. However, age, gender and functional comorbidity index were associated to higher anticholinergic exposure, depending on the list used.

CONCLUSIONS

Repeated CGAs may result as more appropriate anticholinergic medication use. The selection of the list may affect the results and therefore the selection of the list is important.

Temporal trends for donepezil utilization among older people

To examine and characterize overall donepezil and concomitant utilization with β-blockers, yearly, in older New Zealanders. Deidentified data from the Pharmaceutical claims database and the National Minimum Dataset were obtained for 2011 to 2013 from the Ministry of Health. Population-level data were extracted for donepezil and β-blockers utilization, measured by defined daily dose (DDD) per thousand older people per day (TOPD). Donepezil utilization increased from 5.2 to 8.2 DDD/TOPD between 2011 and 2013. In 2011, the number of prevalent users was 4634, the mean age was 79.4±6.6 years and 57.5% were women. Highest use by age for donepezil was in those aged 85 years or older (2.3 DDD/TOPD), followed by those aged 80-84 years (2.2 DDD/TOPD). The mean utilization volumes were significantly lower for donepezil 5 mg (Student t-test=9.86; P<0.05) and 10 mg (10.90; P<0.05) in the 65- to 69-year age group compared with the 80- to 84-year age group, whereas the proportion of concomitant utilization of donepezil with β-blockers decreased (17.9% to 5.1%). Donepezil utilization in DDD/TOPD increased by three-fifths between 2011 and 2013. Prescribers appear to be aware of the potential risk of bradycardia with the concomitant use of donepezil and β-blockers.

Concordance Between Anticholinergic Burden Scales

OBJECTIVES

To evaluate concordance of five commonly used anticholinergic scales.

DESIGN

Cross-sectional secondary analysis.

SETTING

Pittsburgh, Pennsylvania, and Memphis, Tennessee.

PARTICIPANTS

Community-dwelling adults aged 70 to 79 with baseline medication data from the Health, Aging, and Body Composition Study (N = 3,055).

MEASUREMENTS

Any anticholinergic use, weighted scores, and total standardized daily dosage were calculated using five anticholinergic measures (Anticholinergic Cognitive Burden (ACB) Scale, Anticholinergic Drug Scale (ADS), Anticholinergic Risk Scale (ARS), Drug Burden Index anticholinergic component (DBI-ACh), and Summated Anticholinergic Medications Scale (SAMS)). Concordance was evaluated using kappa statistics and Spearman rank correlations.

RESULTS

Any anticholinergic use in rank order was 51% for the ACB, 43% for the ADS, 29% for the DBI-ACh, 23% for the ARS, and 16% for the SAMS. Kappa statistics for all pairwise use comparisons ranged from 0.33 to 0.68. Similarly, concordance as measured using weighted kappa statistics ranged from 0.54 to 0.70 for the three scales not incorporating dosage (ADS, ARS, ACB). Spearman rank correlation between the DBI-ACh and SAMS was 0.50.

CONCLUSION

Only low to moderate concordance was found between the five anticholinergic scales. Future research is needed to examine how these differences in measurement affect their predictive validity with respect to clinically relevant outcomes, such as cognitive impairment.

The Influence of Patient Characteristics on Anticholinergic Events in Older People

Aims

To examine patient characteristics that predict adverse anticholinergic-type events in older people.

Methods

This retrospective population-level study included 2,248 hospitalised patients. Individual data on medicines that are commonly associated with anticholinergic events (delirium, constipation and urinary retention) were identified. Patient characteristics examined were medicines with anticholinergic effects (ACh burden), age, sex, non-anticholinergic medicines (non-ACM), Charlson comorbidity index scores and ethnicity. The Akaike information criterion was used for model selection. The data were analysed using logistic regression models for anticholinergic events using the software NONMEM.

Results

ACh burden was found to be a significant independent predictor for developing an anticholinergic event [adjusted odds ratio (aOR): 3.21, 95% CI: 1.23-5.81] for those taking an average of 5 anticholinergic medicines compared to those taking 1. Both non-ACM and age were also independent risk factors (aOR: 1.41, 95% CI: 1.31-1.51 and aOR: 1.08, 95% CI: 1.05-1.10, respectively).

Conclusion

To our knowledge, this is the first study that has examined population-level data in a nonlinear model framework to predict anticholinergic-type adverse events. This study evaluated the relationship between important patient characteristics and the occurrence of anticholinergic-type events. These findings reinforce the clinical significance of reviewing anticholinergic medicines in older people.

Psychoactive prescribing for older people--what difference does 15 years make?

OBJECTIVE

The objective of the study was to review prescribing of psychoactive medications for older residents of the Tayside region of Scotland.

METHODS

The analysis used community prescribing data in 1995 and 2010 for all older residents in Tayside. For each psychoactive drug class, the name of the most recently prescribed drug and the date prescribed were extracted. The relative risk (RR) and 95% confidence intervals (CI) for patients receiving psychoactive medication in 2010 were compared with those for patients in 1995. Psychoactive prescribing was analyzed by year, age, gender, and deprivation classification. The chi-squared test was used to calculate statistical significance.

RESULTS

Total psychoactive prescribing in people over the age of 65 years has increased comparing 1995 with 2010. Antidepressant [RR = 2.5 (95% CI 2.41-2.59) p < 0.001] and opioid analgesia [RR = 1.21 (1.19-1.24) p < 0.001] prescriptions increased between 1995 and 2010. Hypnotics/anxiolytic [RR = 0.69 (0.66-0.71) p < 0.001] and antipsychotic [RR = 0.83 (0.77-0.88) p < 0.001] prescriptions decreased between 1995 and 2010. An increase in psychoactive prescribing is particularly marked in lower socioeconomic groups. Patients in the least affluent fifth of the population had RR = 1.25 (1.20-1.29) [p < 0.001] of being prescribed one to two psychoactive medications and RR = 1.81 (1.56-2.10) [p < 0.001] of being prescribed three or more psychoactive medications in 2010 compared with those in 1995. The RRs for the most affluent fifth were RR = 1.14 (1.1-1.19) [p < 0.001] and RR = 1.2 (1.01-1.42) [p < 0.001] for one to two, and three or more medications, respectively.

CONCLUSION

Psychoactive medication prescribing has increased comparing 1995 with 2010, with increases disproportionately affecting patients in lower socioeconomic groups. The availability of new psychoactive drugs, safety concerns, and economic factors may explain these increases.

Impact of residential medication management reviews on anticholinergic burden in aged care residents

OBJECTIVES

The primary objective of this study was to investigate the impact of Residential Medication Management Reviews (RMMRs) on anticholinergic burden quantified by seven anticholinergic risk scales.

DESIGN

Retrospective analysis.

SETTING

Accredited pharmacists conducted RMMRs in aged-care facilities (ACFs) in Sydney, Australia.

PARTICIPANTS

RMMRs pertained to 814 residents aged 65 years or older.

MEASUREMENTS

Anticholinergic burden was quantified using seven scales at baseline, after pharmacists' recommendations and after the actual GP uptake of pharmacists' recommendations. Change in the anticholinergic burden was measured using the Wilcoxon sign rank test.

RESULTS

At baseline, depending on the scale used to estimate the anticholinergic burden, between 36% and 67% of patients were prescribed at least one regular anticholinergic medication (ACM). Anticholinergic burden scores were significantly (p < 0.001) lower after pharmacists' recommendations as determined by each of the seven scales. The reduction in anticholinergic burden was also significant (p < 0.001) after GPs' acceptance of the pharmacists' recommendations according to all scales with the exception of one scale which reached borderline significance (p = 0.052).

CONCLUSION

Despite the limitations of the retrospective design and differences in the estimation of anticholinergic burden, this is the first study to demonstrate that RMMRs are effective in reducing ACM prescribing in ACF residents, using a range of measures of anticholinergic burden. Future studies should focus on whether a decrease in anticholinergic burden will translate into improvement in clinical outcomes.

Donepezil Adherence, Persistence and Time to First Discontinuation in a Three-Year Follow-Up of Older People

Background

Donepezil is indicated for the management of mild to moderate dementia, particularly in Alzheimer's disease. Several studies have described low adherence rates with donepezil.

Aim

To examine and measure donepezil adherence, persistence and time to first discontinuation in older New Zealanders.

Methods

An inception cohort of 1,999 new users of donepezil, aged 65 years or older, were identified from the Pharmaceutical Collections and National Minimum Dataset from 1 November 2010 to 31 December 2013. Kaplan-Meier curves and Cox regression analysis were used to estimate the cumulative probability and risk of time to first discontinuation of donepezil therapy.

Results

The mean age of the cohort was 79.5 ± 6.4 years and included 42.7% females. Adherence was high (89.0%), while the proportion of donepezil dispensings (81.0-32.5%) declined between 6 and 36 months. Persistence between the 1st and 6th dispensing visit decreased by 19.0%, and 11.0% of the total cohort had a gap of 31 days or more. The adjusted risk of time to first discontinuation in the non-adherent group was 2.2 times (95% CI 1.9-2.6) that of the adherent group.

Conclusions

The non-adherent new donepezil users, on average, discontinued faster than the adherent group. Time to first discontinuation in this study was higher compared to discontinuation rates observed in clinical trials.

Measuring anticholinergic drug exposure in older community-dwelling Australian men: a comparison of four different measures

AIMS

Anticholinergic drug exposure is associated with adverse outcomes in older people. While a number of tools have been developed to measure anticholinergic drug exposure, there is limited information about the agreement and overlap between the various scales. The aim of this study was to investigate the agreement and overlap between different measures of anticholinergic drug exposure in a cohort of community-dwelling older men.

METHODS

A cross-sectional study was used to compare anticholinergic drug exposure calculated using the Anticholinergic Risk Scale (ARS), the Anticholinergic Drug Scale (ADS), the Anticholinergic Cognitive Burden (ACB) and the Drug Burden Index anticholinergic subscale (DBI-ACH) in a cohort of community-dwelling men aged 70 years and older (n = 1696). Statistical agreement, expressed as Cohen's kappa (κ), between these measurements was calculated.

RESULTS

Differences were found between the tools regarding the classification of anticholinergic drug exposure for individual participants. Thirteen percent of the population used a drug listed as anticholinergic on the ARS, 39% used a drug listed on the ADS and the ACB, and 18% of the population used one or more anticholinergic drugs listed on the DBI-ACH. While agreement was good between the ACB and ADS (κ = 0.628, 95% CI 0.593, 0.664), little agreement was found between remaining tools (κ = 0.091-0.264).

CONCLUSIONS

With the exception of the ACB and ADS, there was poor agreement regarding anticholinergic drug exposure among the four tools compared in this study. Great care should be taken when interpreting anticholinergic drug exposure using existing scales due to the wide variability between the different scales.

A predictive in vitro model of the impact of drugs with anticholinergic properties on human neuronal and astrocytic systems

The link between off-target anticholinergic effects of medications and acute cognitive impairment in older adults requires urgent investigation. We aimed to determine whether a relevant in vitro model may aid the identification of anticholinergic responses to drugs and the prediction of anticholinergic risk during polypharmacy. In this preliminary study we employed a co-culture of human-derived neurons and astrocytes (NT2.N/A) derived from the NT2 cell line. NT2.N/A cells possess much of the functionality of mature neurons and astrocytes, key cholinergic phenotypic markers and muscarinic acetylcholine receptors (mAChRs). The cholinergic response of NT2 astrocytes to the mAChR agonist oxotremorine was examined using the fluorescent dye fluo-4 to quantitate increases in intracellular calcium [Ca2+]i. Inhibition of this response by drugs classified as severe (dicycloverine, amitriptyline), moderate (cyclobenzaprine) and possible (cimetidine) on the Anticholinergic Cognitive Burden (ACB) scale, was examined after exposure to individual and pairs of compounds. Individually, dicycloverine had the most significant effect regarding inhibition of the astrocytic cholinergic response to oxotremorine, followed by amitriptyline then cyclobenzaprine and cimetidine, in agreement with the ACB scale. In combination, dicycloverine with cyclobenzaprine had the most significant effect, followed by dicycloverine with amitriptyline. The order of potency of the drugs in combination frequently disagreed with predicted ACB scores derived from summation of the individual drug scores, suggesting current scales may underestimate the effect of polypharmacy. Overall, this NT2.N/A model may be appropriate for further investigation of adverse anticholinergic effects of multiple medications, in order to inform clinical choices of suitable drug use in the elderly.

Drug Burden Index in older adults: theoretical and practical issues

Anticholinergic and sedative medications are commonly used in older adults and are associated with adverse clinical outcomes. The Drug Burden Index was developed to measure the cumulative exposure to these medications in older adults and its impact on physical and cognitive function. This narrative review discusses the research and clinical applications of the Drug Burden Index, and its advantages and limitations, compared with other pharmacologically developed measures of high-risk prescribing.