Edwin C K Tan

• PhD
• Senior Lecturer at The University of Sydney

Dementia is an umbrella term for several diseases characterised by cognitive decline in at least one cognitive domain which impacts a person’s ability to independently perform complex activities of daily living. Mild cognitive impairment is characterised by cognitive impairment, with minimal impact on activities of daily living. Most people with de...

Antipsychotics are used to manage behaviours and psychological symptoms of dementia. While antipsychotics have been associated with increased risk of adverse outcomes, factors associated with these outcomes have been understudied. Thus, the aim of this study was to identify factors associated with risk of hospitalisation and mortality in older peop...

Pharmacogenetic testing provides patient genotype information which could influence medication selection and dosing for optimal patient care. Insurance coverage for pharmacogenetic testing varies widely. A better understanding of the commonly used medications with clinically important pharmacogenetic recommendations can inform which medications and...

Background Long-term care improves independence and quality of life of persons with dementia (PWD). The influence of socioeconomic status on access to long-term care was understudied. Objective To explore the socioeconomic disparity in long-term care for PWD. Methods This registry-based study included 14,786 PWD, registered in the Swedish registr...

Observational studies on the cancer–dementia relationship have yielded controversial results. This study systematically reviews the evidence to clarify this association. We searched Embase, Global Health, Ovid Medline, and APA PsycInfo. Colorectal and lung cancers showed the greatest risk reduction for all‐cause dementia (ACD) and Alzheimer's disea...

Background Despite the health and societal burden that Alzheimer’s disease (AD) has on the elderly population, the underlying cause is not fully understood. Researchers are investigating possible mechanisms, and current studies have suggested that a number of comorbidities increase/decrease the likelihood of AD onset. The aim of the current study w...

Introduction Thiopurine drugs are metabolized by thiopurine methyltransferase ( TPMT ) and low TPMT activity can result in severe adverse drug reactions. Therefore, TPMT testing is recommended for individuals receiving thiopurines to reduce the risk of toxicity. Objectives The objectives of this study were to assess the rate of TPMT testing among...

Introduction Evidence on patient experiences with pain in hospitals and its impact on post‐discharge outcomes is limited. This study investigated the prevalence of pain in hospitals, patient characteristics associated with pain management adequacy, and the link between pain experiences, care ratings, readmission and emergency department visits afte...

Objectives: This paper aimed to develop a model to describe help-seeking for dementia diagnosis. The practical model is intended to guide public health interventions to increase help-seeking. Method: The model was developed by our multidisciplinary team based on qualitative semi-structured interviews in English (n = 33) and Chinese (n = 8) with...

Issue Addressed The uptake of recommended preventative measures is a critical concern for protecting the public against COVID‐19 outbreaks and future pandemics. However, it is unclear to what extent COVID‐19 preventative measures were followed in Australia. This study aims to determine adherence level to COVID‐19 preventative measures in 2021, and...

Objectives To identify the prevalence of and factors associated with medication use in people living with dementia in the community. Methods A cross‐sectional study using baseline data from a randomised controlled trial known as the Interdisciplinary Home‐bAsed Reablement Program (I‐HARP) between 2018 and 2021 in Sydney, Australia. Participants in...

A significant limitation of the ‘one size fits all’ medication approach is the lack of consideration for special population groups. 3D printing technology has revolutionised the landscape of pharmaceuticals and pharmacy practice, playing an integral role in enabling on-demand production of customised medication. Compared to traditional pharmaceutic...

Background Observational Alzheimer’s disease (AD) cohorts including the Australian, Biomarkers, Imaging and Lifestyle (AIBL) Study have enhanced our understanding of AD. The generalizability of findings from AIBL to the general population has yet to be studied. Objective We aimed to compare characteristics of people with AD dementia in AIBL to 1)...

Objective: This study aims to explore the perspectives and experiences of Australian caregivers and community pharmacists about pediatric melatonin use. Methods: A convenience sample of caregivers with children (aged 11-16 years) using melatonin as a sleep aid and community pharmacists (including pharmacist interns) were recruited. Participants...

Introduction Pharmacological management is a vital aspect of dementia care. Suboptimal medication prescribing and adverse drug reactions are major causes for ongoing concerns for the quality of care. This review aims to investigate the existence and comprehensiveness of Australian guidelines dedicated to supporting dementia care in the context of p...

Centenarians represent a phenomenon of successful aging. This systematic review aimed to understand lifestyles and health practices, focusing on diet and medication use for healthy longevity in community-based adults 95 years or over. Medline, CINAHL, Scopus, and gray literature were searched from 1 January 2000 to 10 December 2022. Study quality w...

Background The associations between mood disorders (anxiety and depression) and mild cognitive impairment (MCI) or Alzheimer’s dementia (AD) remain unclear. Methods Data from the Australian Imaging, Biomarker & Lifestyle (AIBL) study were subjected to logistic regression to determine both cross-sectional and longitudinal associations between anxie...

INTRODUCTION Mounting evidence suggests that certain comorbidities may influence the clinical evolution of Alzheimer's dementia (AD). METHODS We conducted logistic regression analyses on the medical history and cognitive health diagnoses of participants in the Australian Imaging, Biomarker & Lifestyle study (n = 2443) to investigate cross‐sectiona...

Centenarians represent a phenomenon of successful aging, yet little is known about their lifestyle and health practices, including diet/nutrition, medication use, and health conditions. A protocol for this systematic review was registered previously(1). We systematically searched Medline, CINAHL, Scopus, and grey literature from 2000 to 2022, limit...

Surgical site infection (SSI) is a common issue post-surgery which often prolongs hospitalization and can lead to serious complications such as sternal wound infection following cardiac surgery via median sternotomy. Controlled release of suitable antibiotics could allow maximizing drug efficacy and safety, and therefore achieving a desired therape...

An inverse association between cancer and Alzheimer’s disease (AD) has been demonstrated; however, the association between cancer and mild cognitive impairment (MCI), and the association between cancer and cognitive decline are yet to be clarified. The AIBL dataset was used to address these knowledge gaps. The crude and adjusted odds ratios for MCI...

Highlights •Compared to Swedish-born people, foreign-born people were less likely to receive dementia diagnostic tests. •Being born in Africa or Europe was associated with lower chance of receiving cholinesterase inhibitors. •Asian-born people had higher chance of receiving cholinesterase inhibitors, but were less likely to receive memantine. •Disp...

Introduction: This is a systematic review of prescribing, clinical, patient-reported, and health utilization outcomes of goal-directed medication reviews in older adults. Methods: A systematic review was conducted using MEDLINE, EMBASE, SCOPUS and CINAHL databases to identify studies examining outcomes of goal-directed medication reviews in huma...

Older adults are at an increased risk of drug-related problems, especially following discharge from hospital. Drug-related readmissions place a large burden on the patient and the healthcare system. However, previous studies report inconsistent results on the prevalence and associated risk factors for drug-related hospital readmissions in older adu...

Background Older people with dementia are at a particularly high risk of poisonings and their subsequent harms. Objective This review aimed to describe the key agents, incidence, risk factors, and disposition of poisonings in people with dementia reported in the literature. Methods Medline, Embase, CINAHL, and PsycINFO databases were searched fro...

Despite melatonin's popularity as a pediatric sleep-aid, little has been investigated around caregivers' understanding and perception of melatonin use for their dependent. This scoping review analyzes the current literature on pediatric melatonin use, to understand how caregivers' perceptions around melatonin are shaped by their illness/medication-...

Background: Medication-related hospitalisations present an opportunity for de-prescribing and simplification of medication regimens. The Medication Regimen Complexity Index (MRCI) is a tool for measuring the complexity of medication regimens. Objectives: To evaluate whether MRCI changes following medication-related hospitalisations, and to evalu...

The current healthcare dynamic has shifted from one-size-fits-all to patient-centred care, with our increased understanding of pharmacokinetics and pharmacogenomics demanding a switch to more individualised therapies. As the pharmaceutical industry remains yet to succumb to the push of a technological paradigm shift, pharmacists lack the means to p...

Background Historically, research questions have been posed by the pharmaceutical industry or researchers, with little involvement of consumers and healthcare professionals. Objective To determine what questions about medicine use are important to people living with dementia and their care team and whether they have been previously answered by res...

Background Health-related quality of life (HRQoL) is an important outcome measure when considering medical treatment; however, the impact of polypharmacy on trajectories of HRQoL over time is unknown. This study aimed to investigate the association between polypharmacy status and trajectories of HRQoL in older adults. Methods A longitudinal cohort...

Objectives: The aims of this systematic review were to identify the prevalence and risk factors associated with of drug-related problems (DRPs) in people living with dementia in the community. Design: A systematic review and meta-analysis. Setting and participants: People with dementia living in the community. Methods: Six databases (Embase,...

Objectives Despite limited evidence of clinical benefits, dietary supplement use is increasingly common among older adults. The aim of this study was to characterise the prevalence of dietary supplement use in a national sample of community-dwelling middle-aged and older adults and investigate factors associated with its use.Design/Setting/Particip...

The measurement of hydrogen–methane breath gases is widely used in gastroenterology to evaluate malabsorption syndromes and bacterial overgrowth. Laboratories offering breath testing provide variable guidance regarding oral hygiene practices prior to testing. Given that oral dysbiosis has the potential to cause changes in breath gases, it raises co...

Abstract Background Lower socioeconomic position (SEP) was associated with higher risk of morbidity and mortality. However, the influence of SEP on diagnosis and medication use in dementia is understudied. Our study aimed to explore the impact of patients’ SEP on dementia diagnostic process and medications. Method In this longitudinal cohort study...

Background Adverse drug events (ADEs) remain a key contributor to hospitalisations, resulting in long hospital stays and readmissions. Information pertaining to the specific medications and clinical factors associated with these outcomes is limited. Hence, a better understanding of these factors and their relationship to ADEs is required. Objectiv...

Objective: To explore the dementia diagnostic process and drug prescription for persons with dementia (PWD) with different socioeconomic status (SES). Design: Register-based cohort study. Setting and participants: This study included 74,414 PWD aged ≥65 years from the Swedish Dementia Register (2007-2018). Their data were linked with the Swedi...

Background Polypharmacy, the use of multiple medications by one individual, may be associated with adverse health outcomes including poor cognition. However, it remains unclear whether a longitudinal relationship exists. Objectives To investigate the association between polypharmacy and 3-year cognitive ability in older adults. Methods A longitud...

Objectives To externally validate a model for medication‐related dental outcomes in (i) a general older population with dementia and (ii) a matched population without dementia. Subjects and Methods This validation study used population‐based data from seven Swedish national registers (2008–2017). Individuals aged 60+ with dementia were matched to...

Residents of long-term care facilities (LTCFs) are exposed to polypharmacy. 1 There is a possible association between polypharmacy and falls, hospitalizations, and mortality. 2 , 3 Polypharmacy definition ranges between the use of more than 2 to 11 medications. 4 The definition “9 or more regular medications” is the most common in LTCFs. 5 Lack of...

Objectives To assess the prevalence and characteristics of psychotropic medication-related hospitalizations in older people. Design Systematic review with meta-analysis. Setting and Participants: Older adults (≥65 years of age) with psychotropic-related hospitalizations. Methods A search of published literature was performed in Medline, Embase,...

The measurement of hydrogen–methane breath gases is widely used in gastroenterology to evaluate malabsorption syndromes and bacterial overgrowth. Laboratories offering breath testing provide variable guidance regarding oral hygiene practices prior to testing. Given that oral dysbiosis has the potential to cause changes in breath gases, it raises co...

Pharmaceutical agents are a valuable resource to assist in the care of older persons. Their use in post-acute and long-term care settings is particularly notabledfor example, the proportion of nursing home residents taking 9 or more medications increased from 18% in the mid-1990s to 40% less than 15 years later. Average drug counts are similarly hi...

Background Older people with dementia often have poor oral health. Chronic use of xerogenic medications may contribute to adverse dental outcomes. The aim of our study was to investigate the impact of xerogenic medication classes on the predicted risk for dental health interventions in people with dementia. Method This was a population‐based regis...

Background The efficacy of available treatments for dementia remains limited and few randomized clinical trials have been able to demonstrate the benefits of treating comorbidities in improving outcomes of patients with dementia. In this study, we evaluated temporal changes in the management of comorbidities and survival rates in incident dementia...

Objective To describe the most common types of poisoning exposures, implicated substances and underlying sources of medication error in people with dementia. Design Retrospective analysis of call records from the X Poisons Information Center (PIC). Setting and Participants People with dementia who had a poisoning exposure reported to the X PIC (A...

Objectives Evidence is lacking on how treatment of comorbidities improves outcomes in patients with dementia. In this study, we evaluated temporal changes in the management of comorbidities in relation to survival rates in incident dementia over a 10-year period in Sweden. Design Observational cohort study. Setting and Participants A total of 40,...

Older residents of long-term care facilities (LTCFs), also known as nursing homes, care homes, or residential aged care facilities, often have multiple health conditions and are exposed to polypharmacy. Use of high-risk medications such as opioids, glucose-lowering medications, antithrombotics, and antipsychotics is prevalent among residents of LTC...

Older residents of long-term care facilities (LTCFs), also known as nursing homes, care homes, or residential aged care facilities, often have multiple health conditions and are exposed to polypharmacy. Use of high-risk medications such as opioids, glucose-lowering medications, antithrombotics, and antipsychotics is prevalent among residents of LTC...

Aims The objective of this study is to investigate the association between multiple antihypertensive use and mortality in residents with diagnosed hypertension, and whether dementia and frailty modify this association. Methods This is a two-year prospective cohort study of 239 residents with diagnosed hypertension receiving antihypertensive therap...

Evidence to support the use of antipsychotic medications for the management of delirium symptoms remains limited. The primary objective of this study was to compare the effect of antipsychotic and non-antipsychotic treatments for delirium symptoms among palliative care inpatients. Secondary outcomes were use of midazolam and overall survival. This...

Ocular issues are common, burdensome, and under-researched among residents of aged care services. This study aims to investigate the prevalence of dry eyes or use of ocular lubricants among residents, and the possible association with systemic medications known or suspected to cause dry eyes. A cross-sectional study of 383 residents of six aged car...

Objectives Psychosocial job strain has been associated with a range of adverse health outcomes. The aim of this study was to examine the association between psychosocial job strain and prospective risk of polypharmacy (the prescription of ≥5 medications) and to evaluate whether coping strategies can modify this risk. Methods Cohort study of 9703 w...

Background: Prevention and control of cardiometabolic conditions and cardiovascular disease (CVD) in China may contribute to sustainable CVD reduction globally, given the fact that one-fifth of the worldwide population is in China. Knowing the distribution of behavioral risk factors (e.g., smoking and physical inactivity), especially at a national...

Frailty is a geriatric condition associated with increased vulnerability to adverse drug events and medication-related harm. Existing clinical practice guidelines rarely provide medication management recommendations specific to frail older people. This report presents international consensus principles, generated by the Optimizing Geriatric Pharmac...

Background Older adults with dementia often have poor oral health. Chronic use of xerogenic medications may contribute to adverse dental outcomes. Objective To investigate the impact of xerogenic medication classes on the predicted risk for dental interventions in people with dementia. Methods This was a population-based cohort study involving 30...

Background Statins are associated with muscle-related adverse events, but few studies have investigated the association with fall-related hospitalizations among residents of long-term care facilities (LTCFs). Objective To investigate whether statin use is associated with fall-related hospitalizations from LTCFs. Methods A case-control study was c...

Falls are associated with considerable morbidity and mortality in aged care services and falls risk increasing drugs (FRIDs) are often overlooked as a contributor to falls. This study aims to investigate the association between the risk of falling and use of FRIDs from aged care services. Inverse-probability-weighted multinomial logistic regression...

Objective Our objective was to investigate associations between proton pump inhibitor (PPIs) use and infection-related hospitalizations among residents of long-term care facilities (LTCFs). Methods This was a case–control study of residents aged ≥ 65 years admitted to hospital between July 2013 and June 2015. Residents admitted for infections (cas...

Background Medication use in people with dementia and/or cognitive impairment (PWD/CI) is challenging. As medication experts, pharmacists have an important role in improving care of this vulnerable population. Objective Systematically review evidence for the effectiveness of pharmacist-led interventions on quality use of medicines, quality of life...

Aim While proton pump inhibitors (PPIs) are generally considered safe and well tolerated, frail older people who take PPIs long term may be susceptible to adverse events. This study characterized PPI use and determined factors associated with high-dose use among older adults in residential aged care services (RACSs). Methods A cross-sectional stud...

Objectives: To investigate whether acetylcholinesterase inhibitor (AChEI) use prevents or delays subsequent initiation of psychotropic medications in people with Alzheimer's disease (AD) and Lewy body dementia (LBD). Methods: Cohort study of 17,763 people with AD and LBD, without prior psychotropic use at time of dementia diagnosis, registered i...

Objectives: Previous studies have shown large heterogeneity in the progression of dementia, both within and between patients. This heterogeneity offers an opportunity to limit the global and individual burden of dementia through the identification of factors associated with slow disease progression in dementia. We explored the heterogeneity in dem...

Background One quarter of residents in long-term care facilities (LTCFs) have a diagnosis of CHD or stroke and over half use at least one preventative cardiovascular medication. There have been no studies that have investigated the longitudinal change in secondary preventative cardiovascular medication use in residents in LTCFs over time. Objectiv...

Introduction: Polypharmacy, the use of multiple medications by one individual, is increasingly common among older adults. Caring for the growing number of older people with complex drug regimens and multimorbidity presents an important challenge in the coming years. Areas covered: This article reviews the international trends in the prevalence of...

Background: Little is known about the contribution of ‘pro re nata’ (PRN) medications to overall medication burden in residential aged care services (RACS). Objectives: To determine the frequency of, and factors associated with PRN medication administration in RACS. Measurements: Details of all medications charted for regular or PRN use were extrac...

Background: Alzheimer's disease is the most common form of dementia and is a major contributor to morbidity and mortality in older Australians. Objective: The aim of this article is to provide an overview of available pharmacological therapies for the symptomatic treatment of Alzheimer's disease. Discussion: Acetylcholinesterase inhibitors (AC...

Background Anticholinergic burden is associated with poorer cognitive and functional outcomes in people with dementia. However, the impact of anticholinergics on significant adverse outcomes such as stroke has not been studied previously. Objective To investigate the association between total anticholinergic cognitive burden (ACB) and risk of stro...

Objectives: Medication-induced hyposalivation can increase the risk for oral complications, including dental caries and tooth loss. This problem is particularly important in people with dementia because of their declining ability to maintain oral care. The objective of this study was to describe the association between the number of xerostomic med...

Our study shows that most individuals were members of a class with relatively slow disease progression. This presents a more optimistic prospect for the majority of patients as compared to the mean progression rate of the entire sample. This is important for informing newly diagnosed dementia patients and their caregivers about the course of the di...

Introduction: The aim of this study was to investigate the association between acetylcholinesterase inhibitor (AChEI) use and risk of ischemic stroke and death in people with dementia. Methods: A cohort study of 44,288 people with dementia registered in the Swedish Dementia Registry from 2007 to 2014. Propensity score-matched competing risk regr...

Medication management is becoming increasingly challenging for older people, and there is limited evidence to guide medication prescribing and administration for people with multimorbidity, frailty, or at the end of life. Currently, there is a lack of clear research priorities in the field of geriatric pharmacotherapy. To address this issue, intern...

Objective: To investigate the association between antihypertensive medication regimen intensity and risk of incident dementia in an older population. Design: Prospective, longitudinal cohort study. Participants/setting: A total of 1208 participants aged ≥78 years, free of dementia, and residing in central Stockholm at baseline (2001-2004). Me...

Background: Research into which medications contribute to polypharmacy and the variability in these medications across long-term care facilities (LTCFs) has been minimal. Objective: Our objective was to investigate which medications were more prevalent among residents with polypharmacy and to determine the variability in prescribing of these med...

Objectives: To assess and quantify the risk of drug-induced dry mouth as a side effect in older people. Design: Systematic review and metaanalysis. Setting: A search of the literature was undertaken using Medline, Embase, Cochrane, Web of Science, and PubMed from 1990 to 2016. Participants: Older people (aged ≥60) who participated in interve...

This study aims to investigate national trends in outpatient antihypertensive prescribing in people with dementia in the United States between 2006 and 2012, and to determine clinical and demographic factors associated with different prescribing patterns. Outpatient visits by people aged ≥65 years with documented dementia were analyzed in the Natio...

This study aimed to investigate the ability of the FRAIL-NH and Frailty Index to predict hospitalization and mortality in residential age care facilities over a 12-month follow up. A total of 383 residents (age 87.5 ± 6.2 years, 77.5% females) of six Australian facilities participated in the study. At baseline 35.9% of residents were classified as...

Background Benzodiazepines are commonly prescribed in residential aged care facilities (RACFs) for their sedative and anxiolytic effects. The objective of this study was to investigate the association between benzodiazepine use and sleep quality in residents of RACFs. MethodsA cross-sectional study involving 383 participants was conducted in six Au...

Objectives: To investigate the association between polypharmacy and medication regimen complexity with time to first hospitalization, number of hospitalizations, and number of hospital days over a 12-month period. Design: A 12-month prospective cohort study. Participants and setting: A total of 383 residents of 6 Australian long-term care faci...

Objectives: To compare the FRAIL-NH scale with the Frailty Index in assessing frailty in residential aged care facilities. Design: Cross-sectional. Setting: Six Australian residential aged care facilities. Participants: Individuals aged 65 and older (N = 383, mean aged 87.5 ± 6.2, 77.5% female). Measurements: Frailty was assessed using the...

Objective: The objectives were to investigate national trends in outpatient antihypertensive prescribing in people with dementia in the United States between 2006 and 2012, and to investigate clinical and demographic factors associated with different antihypertensive prescribing patterns. Methods: This was an analysis of the National Ambulatory Med...

Purpose The purpose of this study is to investigate the association between polypharmacy with health-related quality of life (HRQoL) and medication regimen complexity with HRQoL in residential aged care facilities (RACFs). Methods A cross-sectional study of 383 residents from six Australian RACFs was conducted. The primary exposures were polypharma...

Background: Pharmacist-led medication review is a collaborative service which aims to identify and resolve medication-related problems. Objective: To critically evaluate published systematic reviews relevant to pharmacist-led medication reviews in community settings. Methods: MEDLINE, EMBASE, International Pharmaceutical Abstracts (IPA), Cumul...

Objective: Depressive symptoms are highly prevalent in residential aged care facilities (RACFs). The prevalence of antidepressant use is increasing but the effectiveness of antidepressants in people with dementia is uncertain. The objective of the study was to investigate factors associated with antidepressant use in residents with and without dem...

Polypharmacy is highly prevalent in residential aged care facilities (RACFs). Although polypharmacy is sometimes unavoidable, polypharmacy has been associated with increased morbidity and mortality. To identify and prioritize a range of potential interventions to manage polypharmacy in RACFs from the perspectives of healthcare professionals, healt...

Aim: To investigate analgesic use and pain in people with and without dementia in Australian residential aged are facilities. Methods: A cross-sectional study of 383 residents of six residential aged are facilities was conducted. Nurses assessed self-reported and clinician-observed pain. Analgesic use data were extracted from medication charts....

Rationale, aims and objectives: The prevalence of polypharmacy in residential aged care facilities (RACFs) is high and increasing. Although not necessarily inappropriate, polypharmacy has been associated with drug interactions, adverse drug events, geriatric syndromes and hospital admissions. The aim of this study was to identify and prioritize fa...