Performance of digital technologies in assessing fall risks among older adults with cognitive impairment: a systematic review

Older adults with cognitive impairment (CI) are twice as likely to fall compared to the general older adult population. Traditional fall risk assessments may not be suitable for older adults with CI due to their reliance on attention and recall. Hence, there is an interest in using objective technology-based fall risk assessment tools to assess falls within this population. This systematic review aims to evaluate the features and performance of technology-based fall risk assessment tools for older adults with CI. A systematic search was conducted across several databases such as PubMed and IEEE Xplore, resulting in the inclusion of 22 studies. Most studies focused on participants with dementia. The technologies included sensors, mobile applications, motion capture, and virtual reality. Fall risk assessments were conducted in the community, laboratory, and institutional settings; with studies incorporating continuous monitoring of older adults in everyday environments. Studies used a combination of technology-based inputs of gait parameters, socio-demographic indicators, and clinical assessments. However, many missed the opportunity to include cognitive performance inputs as predictors to fall risk. The findings of this review support the use of technology-based fall risk assessment tools for older adults with CI. Further advancements incorporating cognitive measures and additional longitudinal studies are needed to improve the effectiveness and clinical applications of these assessment tools. Additional work is also required to compare the performance of existing methods for fall risk assessment, technology-based fall risk assessments, and the combination of these approaches.

Physical strength and mental health mediate the association between pain and falls (recurrent and/or injurious) among community-dwelling older adults in Singapore

OBJECTIVE

This study aims to understand if poor physical strength and depression mediate the association between pain and recurrent and/or injurious falls in a community of older adults.

METHODS

Data was obtained from a nationally representative longitudinal cohort study conducted in Singapore, PHASE (Wave I and II), which collected information from community-dwelling older adults above 60 years old. A hurdle negative binomial regression and binomial logistic regression were used to assess the association between pain and recurrent falls, and pain and injurious falls respectively. A subsequent mediation analysis was conducted.

RESULTS

Almost half of the participants (N = 1144, 39.7%) reported having either mild, moderate, or severe pain at baseline, 166 (5.4%) participants experienced injurious falls and 144 (4.7%) participants experienced recurrent falls at Wave II. After adjusting for covariates, the presence of pain significantly influenced recurrent (OR 2.8; 95% CI: 1.8, 4.4) and injurious falls (OR: 1.8; 95% CI: 1.3, 2.5). Mediation analyses demonstrated that poor physical strength and depression had a significant mediation effect between all pain characteristics on recurrent falls. Poor physical strength partially mediates the effects of pain and injurious falls as well. However, the mediating effect of poor physical strength and depression was not observed between other pain characteristics and injurious falls.

CONCLUSIONS

The findings highlighted differences in the underlying mechanisms between pain characteristics affecting recurrent and injurious falls. These insights will be useful for identifying patients most at risk for recurrent or injurious falls, and for tailoring future community-based fall intervention programmes.

Reducing Falls Among Community-Dwelling Older Adults From Clinicians' Perspectives: A Systems Modeling Approach

Background and Objectives

Falls among older adults are a significant health problem globally. Studies of multicomponent fall prevention programs in randomized controlled trials demonstrate effectiveness in reducing falls; however, the translation of research into the community remains challenging. Although there is an increasing interest to understand the factors contributing to implementation barriers, the dynamic relationships between factors are less well examined. Furthermore, evidence on implementation barriers from Asia is lacking as most of these studies originate from the West. As such, this study aims to engage stakeholders in uncovering the factors that facilitate or inhibit implementing community-based fall prevention programs in Singapore, with a focus on the interrelationship between those factors.

Research Design and Methods

Health care professionals familiar with fall prevention programs were invited to discuss the enablers and challenges to the implementation. This effort was facilitated using a systems modeling methodology of Group Model Building (GMB) to share ideas and create a common conceptual model of the challenges. The GMB employs various engagement techniques to draw on the experiences and perceptions of all stakeholders involved.

Results

This process led to the development of a Causal Loop Diagram (CLD), a qualitative conceptual model of the dynamic relationships between the barriers and facilitators of implementing fall prevention programs. Results from the CLD show that implementation is influenced by two main drivers: health care provider factors that influenced referrals, and patient factors that influenced referral acceptance and long-term adherence. Key leverage points for potential interventions were identified as well.

Discussion and Implications

The overall recommendation emphasized closer coordination and collaboration across providers to ensure sustainable and effective community-based fall prevention programs. This has to be supported by a national effort, involving a multidisciplinary stakeholder advisory group. These findings generated would be promising to guide future approaches to fall prevention.

High-Suspicion Subcentimeter Thyroid Nodules: Cost Effectiveness of Active Surveillance versus Fine Needle Aspiration

PURPOSE

To compare the cost-benefit of active surveillance (AS) against immediate fine needle aspiration (FNA) of sonographically suspicious subcentimeter thyroid nodules.

MATERIALS AND METHODS

A Markov model was constructed to compare the cost-benefit of 3 strategies from the point of discovery until death: (a) Surveillance of all nodules, (b) Surveillance of nodules with positive cytology, and (c) Surgery of nodules with positive cytology. The reference case was a 40-year-old woman with a sonographically suspicious subcentimeter thyroid nodule. Transition probabilities, costs, and health state utilities were derived from the literature. Sensitivity analyses were performed to evaluate model uncertainty. Willingness-to-pay threshold was set at $100,000/quality-adjusted life year.

RESULTS

Surveillance of nodules with positive cytology dominated in the reference scenario and was cost-beneficial over Surveillance of all nodules, independent of the utility of AS. Surveillance of all nodules was cost-beneficial only at a life expectancy of <2.6 years or surveillance duration of <4 years.

CONCLUSIONS

While current guidelines recommend AS of sonographically suspicious subcentimeter nodules, the results of this study suggest that immediate FNA (Surveillance of nodules with positive cytology) is more cost-beneficial than AS (Surveillance of all nodules). Patients with positive cytology on FNA may subsequently opt for AS (Surveillance of nodules with positive cytology) or surgery (Surgery of nodules with positive cytology) according to their level of comfort (ie, utility) with AS.

Developing a toolkit for implementing evidence-based guidelines to manage hypertension and diabetes in Cambodia: a descriptive case study

BACKGROUND

In Cambodia, economic development accompanied by health reforms has led to a rapidly ageing population and an increasing incidence and prevalence of noncommunicable diseases. National strategic plans recognize primary care health centres as the focal points of care for treating and managing chronic conditions, particularly hypertension and type 2 diabetes. However, health centres have limited experience in providing such services. This case study describes the process of developing a toolkit to facilitate the use of evidence-based guidelines to manage hypertension and type 2 diabetes at the health-centre level.

METHODS

We developed and revised a preliminary toolkit based on the feedback received from key stakeholders. We gathered feedback through an iterative process of group and one-to-one consultations with representatives of the Ministry of Health, provincial health department, health centres and nongovernmental organizations between April 2019 and March 2021.

RESULTS

A toolkit was developed and organized according to the core tasks required to treat and manage hypertension and type 2 diabetes patients. The main tools included patient identification and treatment cards, risk screening forms, a treatment flowchart, referral forms, and patient education material on risk factors and lifestyle recommendations on diet, exercise, and smoking cessation. The toolkit supplements existing guidelines by incorporating context-specific features, including drug availability and the types of medication and dosage guidelines recommended by the Ministry of Health. Referral forms can be extended to incorporate engagement with community health workers and patient education material adapted to the local context. All tools were translated into Khmer and can be modified as needed based on available resources and arrangements with other institutions.

CONCLUSIONS

Our study demonstrates how a toolkit can be developed through iterative engagement with relevant stakeholders individually and in groups to support the implementation of evidence-based guidelines. Such toolkits can help strengthen the function and capacity of the primary care system to provide care for noncommunicable diseases, serving as the first step towards developing a more comprehensive and sustainable health system in the context of population ageing and caring for patients with chronic diseases.

Left Atrial Appendage Occlusion Versus Oral Anticoagulation in Atrial Fibrillation : A Decision Analysis

BACKGROUND

Left atrial appendage occlusion (LAAO) is a potential alternative to oral anticoagulants in selected patients with atrial fibrillation (AF). Compared with anticoagulants, LAAO decreases major bleeding risk, but there is uncertainty regarding the risk for ischemic stroke compared with anticoagulation.

OBJECTIVE

To determine the optimal strategy for stroke prevention conditional on a patient's individual risks for ischemic stroke and bleeding.

DESIGN

Decision analysis with a Markov model.

DATA SOURCES

Evidence from the published literature informed model inputs.

TARGET POPULATION

Women and men with nonvalvular AF and without prior stroke.

TIME HORIZON

Lifetime.

PERSPECTIVE

Clinical.

INTERVENTION

LAAO versus warfarin or direct oral anticoagulants (DOACs).

OUTCOME MEASURES

The primary end point was clinical benefit measured in quality-adjusted life-years.

RESULTS OF BASE-CASE ANALYSIS

The baseline risks for stroke and bleeding determined whether LAAO was preferred over anticoagulants in patients with AF. The combined risks favored LAAO for higher bleeding risk, but that benefit became less certain at higher stroke risks. For example, at a HAS-BLED score of 5, LAAO was favored in more than 80% of model simulations for CHA₂DS₂-VASc scores between 2 and 5. The probability of LAAO benefit in QALYs (>80%) at lower bleeding risks (HAS-BLED score of 0 to 1) was limited to patients with lower stroke risks (CHA₂DS₂-VASc score of 2). Because DOACs carry lower bleeding risks than warfarin, the net benefit of LAAO is less certain than that of DOACs.

RESULTS OF SENSITIVITY ANALYSIS

Results were consistent using the ORBIT bleeding score instead of the HAS-BLED score, as well as alternative sources for LAAO clinical effectiveness data.

LIMITATION

Clinical effectiveness data were drawn primarily from studies on the Watchman device.

CONCLUSION

Although LAAO could be an alternative to anticoagulants for stroke prevention in patients with AF and high bleeding risk, the overall benefit from LAAO depends on the combination of stroke and bleeding risks in individual patients. These results suggest the need for a sufficiently low stroke risk for LAAO to be beneficial. The authors believe that these results could improve shared decision making when selecting patients for LAAO.

PRIMARY FUNDING SOURCE

None.

Cost-Effectiveness of Drug-Coated Balloon Angioplasty Versus Conventional Balloon Angioplasty for Treating Below-the-Knee Arteries in Chronic Limb-Threatening Ischemia: The SINGA-PACLI Trial

PURPOSE

Drug-coated balloon angioplasty (DCBA) has been studied as a potentially superior option compared to conventional percutaneous transluminal angioplasty (PTA) in treating below-the-knee (BTK) arteries in chronic limb-threatening ischemia (CLTI). The aim of this study is to examine the cost-effectiveness of DCBA versus PTA in BTK arteries based on a randomized controlled trial.

MATERIAL AND METHODS

A prospective economic study was embedded in a randomized controlled trial of 138 patients with CLTI. Resource use and health outcomes were assessed at baseline, and at 3, 6 and 12 months post-intervention. Costs were calculated from a societal perspective and health outcomes measured using quality-adjusted life years with probabilistic sensitivity analysis performed to account for subject heterogeneity.

RESULTS

Compared with participants randomized to receive PTA, participants randomized to DCBA gained an average baseline-adjusted quality-adjusted life years (QALYs) of .012 while average total costs were USD$1854 higher; this translates to an incremental cost-effectiveness ratio (ICER) of US$154,500 additional cost per QALY gained. However, the estimate of ICER had substantial variance with only 48% of bootstrap ICERs meeting a benchmark threshold of US$57,705 (the average gross domestic product (GDP) per capita of Singapore).

CONCLUSION

The use of DCBA in BTK arteries in CLTI patients was not cost-effective compared with PTA.

LEVEL OF EVIDENCE

2, Randomized trial.

Impact of the COVID-19 pandemic on a tertiary care public hospital in Singapore: Resources and economic costs

BACKGROUND

The COVID-19 pandemic has prompted hospitals to respond with stringent measures. Accurate estimates of costs and resources used in outbreaks can guide evaluations of responses. We report the financial expenditure associated with COVID-19, the bed-days used for COVID-19 patients and hospital services displaced due to COVID-19 in a Singapore tertiary hospital.

METHODS

We conducted a retrospective cost analysis from January to December 2020 in the largest public hospital in Singapore. Costs were estimated from the hospital perspective. We examined financial expenditures made in direct response to COVID-19; hospital admissions data related to COVID-19 inpatients; and the number of outpatient and emergency department visits, non-emergency surgeries, inpatient days in 2020, compared to preceding years of 2018 and 2019. Bayesian time-series was used to estimate the magnitude of displaced services.

RESULTS

USD$41.96 million was incurred in the hospital for COVID-19 related expenses. Facilities setup and capital assets counted for 51.6% of the expenditure; patient-care supplies comprised 35.1%. Out of the 19,611 inpatients tested for COVID-19 in 2020, 727 (3.7%) had COVID-19. The total inpatient- and ICU-days for COVID-19 patients in 2020 were 8,009 and 8 days respectively. A decline in all hospital services were observed from February following a raised disease outbreak alert level; most services quickly resumed when the lockdown was lifted in June.

CONCLUSION

COVID-19 has led to increase in healthcare expenses and displacement in hospital services. Our findings are useful for informing economic evaluations of COVID-19 response and provide some information about the expected costs of future outbreaks.

Sequential Multiple Assignment Randomized Trial (SMART) to identify optimal sequences of telemedicine interventions for improving initiation of insulin therapy: A simulation study

BACKGROUND

To examine the value of a Sequential Multiple Assignment Randomized Trial (SMART) design compared to a conventional randomized control trial (RCT) for telemedicine strategies to support titration of insulin therapy for Type 2 Diabetes Mellitus (T2DM) patients new to insulin.

METHODS

Microsimulation models were created in R using a synthetic sample based on primary data from 63 subjects enrolled in a pilot study of a smartphone application (App), Diabetes Pal compared to a nurse-based telemedicine strategy (Nurse). For comparability, the SMART and an RCT design were constructed to allow comparison of four (embedded) adaptive interventions (AIs).

RESULTS

In the base case scenario, the SMART has similar overall mean expected HbA1c and cost per subject compared with RCT, for sample size of n = 100 over 10,000 simulations. SMART has lower (better) standard deviations of the mean expected HbA1c per AI, and higher efficiency of choosing the correct AI across various sample sizes. The differences between SMART and RCT become apparent as sample size decreases. For both trial designs, the threshold value at which a subject was deemed to have been responsive at an intermediate point in the trial had an optimal choice (i.e., the sensitivity curve had a U-shape). SMART design dominates the RCT, in the overall mean HbA1c (lower value) when the threshold value is close to optimal.

CONCLUSIONS

SMART is suited to evaluating the efficacy of different sequences of treatment options, in addition to the advantage of providing information on optimal treatment sequences.

Singapore's health-care system: key features, challenges, and shifts

Since Singapore became an independent nation in 1965, the development of its health-care system has been underpinned by an emphasis on personal responsibility for health, and active government intervention to ensure access and affordability through targeted subsidies and to reduce unnecessary costs. Singapore is achieving good health outcomes, with a total health expenditure of 4·47% of gross domestic product in 2016. However, the health-care system is contending with increased stress, as reflected in so-called pain points that have led to public concern, including shortages in acute hospital beds and intermediate and long-term care (ILTC) services, and high out-of-pocket payments. The main drivers of these challenges are the rising prevalence of non-communicable diseases and rapid population ageing, limitations in the delivery and organisation of primary care and ILTC, and financial incentives that might inadvertently impede care integration. To address these challenges, Singapore's Ministry of Health implemented a comprehensive set of reforms in 2012 under its Healthcare 2020 Masterplan. These reforms substantially increased the capacity of public hospital beds and ILTC services in the community, expanded subsidies for primary care and long-term care, and introduced a series of financing health-care reforms to strengthen financial protection and coverage. However, it became clear that these measures alone would not address the underlying drivers of system stress in the long term. Instead, the system requires, and is making, much more fundamental changes to its approach. In 2016, the Ministry of Health encapsulated the required shifts in terms of the so-called Three Beyonds-namely, beyond health care to health, beyond hospital to community, and beyond quality to value.

Trends in functional disability and cognitive impairment among the older adult in China up to 2060: estimates from a dynamic multi-state population model

Background

Available evidence suggests that cognitive impairment (CI), which leads to deficits in episodic memory, executive functions, visual attention, and language, is associated with difficulties in the capacity to perform activities of daily living. Hence any forecast of the future prevalence of functional disability should account for the likely impact of cognitive impairment on the onset of functional disability. Thus, this research aims to address this gap in literature by projecting the number of older adults in China with functional disability and cognitive impairment while accounting for the impact of cognitive impairment on the onset of functional disability.

Methods

We developed and validated a dynamic multi-state population model which simulates the population of China and tracks the transition of Chinese older adults (65 years and older) from 2010 to 2060, to and from six health states—(i) active older adults without cognitive impairment, (ii) active older adults with cognitive impairment, (iii) older adults with 1 to 2 ADL limitations, (iv) older adults with cognitive impairment and 1 to 2 ADL limitations, (v) older adults with 3 or more ADL limitations, and (vi) older adults with cognitive impairment and 3 or more ADL limitations.

Results

From 2015 to 2060, the number of older adults 65 years and older in China is projected to increase, of which the number with impairment (herein referred to as individuals with cognitive impairment and/or activity of daily living limitations) is projected to increase more than fourfold from 17·9 million (17·8–18·0) million in 2015 to 96·2 (95·3–97·1) million by 2060. Among the older adults with impairment, those with ADL limitations only is projected to increase from 3·7 million (3·6–3·7 million) in 2015 to 23·9 million (23·4–24·6 million) by 2060, with an estimated annual increase of 12·2% (12·1–12·3); while that for cognitive impairment only is estimated to increase from 11·4 million (11·3–11·5 million) in 2015 to 47·8 million (47·5–48·2 million) by 2060—this representing an annual growth of 7·07% (7·05–7·09).

Conclusion

Our findings suggest there will be an increase in demand for intermediate and long-term care services among the older adults with functional disability and cognitive impairment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02309-4.

Role of caregiver factors in outpatient medical follow-up post-stroke: observational study in Singapore

Background

Outpatient medical follow-up post-stroke is not only crucial for secondary prevention but is also associated with a reduced risk of rehospitalization. However, being voluntary and non-urgent, it is potentially determined by both healthcare needs and the socio-demographic context of stroke survivor-caregiver dyads. Therefore, we aimed to examine the role of caregiver factors in outpatient medical follow-up (primary care (PC) and specialist outpatient care (SOC)) post-stroke.

Method

Stroke survivors and caregivers from the Singapore Stroke Study, a prospective, yearlong, observational study, contributed to the study sample. Participants were interviewed 3-monthly for data collection. Counts of PC and SOC visits were extracted from the National Claims Database. Poisson modelling was used to explore the association of caregiver (and patient) factors with PC/SOC visits over 0–3 months (early) and 4–12 months (late) post-stroke.

Results

For the current analysis, 256 stroke survivors and caregivers were included. While caregiver-reported memory problems of a stroke survivor (IRR: 0.954; 95% CI: 0.919, 0.990) and caregiver burden (IRR: 0.976; 95% CI: 0.959, 0.993) were significantly associated with lower early post-stroke PC visits, co-residing caregiver (IRR: 1.576; 95% CI: 1.040, 2.389) and negative care management strategies (IRR: 1.033; 95% CI: 1.005, 1.061) were significantly associated with higher late post-stroke SOC visits.

Conclusion

We demonstrated that the association of caregiver factors with outpatient medical follow-up varied by the type of service (i.e., PC versus SOC) and temporally. Our results support family-centred care provision by family physicians viewing caregivers not only as facilitators of care in the community but also as active members of the care team and as clients requiring care and regular assessments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-021-01405-z.

Stroke Rehabilitation Use and Caregiver Psychosocial Health Profiles in Singapore: A Latent Profile Transition Analysis

OBJECTIVES

To identify and describe caregiver profiles based on their psychosocial health characteristics over a 12-month period and transitions among these profiles, to determine if stroke rehabilitation use at 12 months post-stroke differed by caregiver profile transition patterns, and to investigate if caregiver profiles at 3 months post-stroke moderate the association of stroke rehabilitation use at 3 months and 12 months post-stroke after accounting for covariates.

DESIGN

Latent profile transition analysis of caregiver psychosocial health with stroke rehabilitation use at 12 month post-stroke as outcome.

SETTING AND PARTICIPANTS

A total of 149 stroke patient-caregiver dyads from the Singapore Stroke Study.

METHODS

Cross-sectional latent profile analyses were conducted on caregiver psychosocial health indicators of burden, depression, health status, quality of relationship with patient, and social support. Changes in latent profile classification over 3 time points (baseline, 3 months, and 12 months post-stroke) were analyzed using latent transition analysis. A transition model with stroke rehabilitation use at 12 months post-stroke as the outcome was tested after accounting for covariates.

RESULTS

Two distinct caregiver psychosocial health latent profiles were found across time: nondistressed and distressed. Most caregivers were classified as nondistressed and remained nondistressed over time. Distressed caregivers at baseline were 76% likely to become nondistressed at 12 month post-stroke. Regardless of profile transition patterns, nondistressed caregivers at 12 months post-stroke tended to have cared for stroke rehabilitation nonusers at 12 months post-stroke. Patient depression explained profile classification at 3 months and 12 months post-stroke. After accounting for covariates, rehabilitation users at 3 months post-stroke tended to continue using rehabilitation at 12 months post-stroke only when they had nondistressed caregivers at 3 months post-stroke.

CONCLUSIONS AND IMPLICATIONS

Whether caregiver adaptation explains the associations between the latent profile transition patterns and rehabilitation use at 12 months post-stroke should be examined. Early psychosocial health assessment and sustained support should be made available to stroke caregivers to enhance their well-being and subsequent patient rehabilitation participation.

Abstract P227: Incentives for Uptake and Adherence With Outpatient Stroke Rehabilitation: A Three Arm Randomized Controlled Trial

Introduction: While rehabilitation has been demonstrated to be effective in improving outcomes of stroke, uptake of outpatient rehabilitation services (ORS) in Singapore remains relatively low. This study aims to determine if rehabilitation uptake and adherence can be increased by providing coordinated transportation (increased convenience) and eliminating out-of-pocket costs (reduced expense).

Hypothesis: It was hypothesized that the uptake rate of ORS over 3 months, number of sessions attended, and time to discontinuation would be greater for participants in the intervention arms of which barriers of transportation and out-of-pocket costs are addressed, as compared to participants in the control arm.

Methods: A total of 266 participants were recruited from the stroke and acute rehabilitation units of two tertiary hospitals in Singapore, and randomized to one of three study arms: the control arm, denoted Education ( E ), inclusive of a stroke rehabilitation educational program; the first intervention arm, denoted Transportation Incentives ( T ), inclusive of free transportation services for the first 3 months post-discharge; or the second intervention arm, denoted, Transportation & Sessions Incentives ( T&S ), inclusive of up to 3 months of both free transportation and no out-of-pocket costs for participants’ stroke ORS.

Results: The uptake rate of ORS was 73.0% for E (CI, 63.8%-82.3%), 81.8% for T (CI, 73.8%-89.8%), and 84.3% for T&S (CI, 76.7%-91.8%). The differences of T and T&S versus the control arm ( E ) were not statistically significant (p = 0.22 and p = 0.10, respectively). However, the average number of rehabilitation sessions attended were significantly higher in both the intervention arms: 5.50 (SD, 7.65) for T and 7.51 (SD, 9.52) for T&S versus 3.26 (SD, 4.22) for the control arm ( E ) (p-value for T vs E = 0.017; p-value for T&S vs E = 0.000.) Kaplan-Meier analysis indicated that persistence was higher for T&S compared to E (p=0.029).

Conclusions: This study has demonstrated that incentives can improve utilization of ORS. Such incentives should be considered in finance policy, such as care bundling, for stroke or similar common conditions.

Heart Disease and Stroke Statistics-2021 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2021 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors related to cardiovascular disease.

RESULTS

Each of the 27 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Post-stroke patients with moderate function have the greatest risk of falls: a National Cohort Study

BACKGROUND

Stroke patients have increased risks of falls. We examined national registry data to evaluate the association between post-stroke functional level and the risk of low falls among post-stroke patients.

METHODS

This retrospective cohort study analyzed data from national registries to examine the risk factors for post-stroke falls. Data for patients who suffered ischemic strokes and survived the index hospital admission was obtained from the Singapore National Stroke Registry and matched to the National Trauma Registry, from 2011 to 2015. The primary outcome measure was a low fall (fall height ≤ 0.5 m). Competing risk analysis was performed to examine the association between functional level (by modified Rankin score [mRS] at discharge) and the risk of subsequent low falls.

RESULTS

In all, 2255 patients who suffered ischemic strokes had recorded mRS. The mean age was 66.6 years and 58.5% were men. By the end of 2015, 54 (2.39%) had a low fall while 93 (4.12%) died. After adjusting for potential confounders, mRS was associated with fall risk with an inverted U-shaped relationship. Compared to patients with a score of zero, the sub-distribution hazard ratio (SHR) increased to a maximum of 3.42 (95%CI:1.21-9.65, p = 0.020) for patients with a score of 2. The SHR then declined to 2.45 (95%CI:0.85-7.12, p = 0.098), 2.86 (95%CI:0.95-8.61, p = 0.062) and 1.93 (95%CI:0.44-8.52, p = 0.38) for patients with scores of 3, 4 and 5 respectively.

CONCLUSIONS

An inverted U-shaped relationship between functional status and fall risk was observed. This is consistent with the complex interplay between decreasing mobility (hence decreased opportunity to fall) and increasing susceptibility to falls. Fall prevention intervention could be targeted accordingly. (263 words).

Dyadic approach to post-stroke hospitalizations: role of caregiver and patient characteristics

Aim

To study the association of caregiver factors and stroke patient factors with rehospitalizations over the first 3 months and subsequent 3–12 months post-stroke in Singapore.

Methods

Patients with stroke and their caregivers were recruited in the Singapore Stroke Study, a prospective yearlong cohort. While caregiver and patient variables were taken from this study, hospitalization data were extracted from the national claims database. We used Poisson modelling to perform bivariate and multivariable analysis with counts of hospitalization as the outcome.

Results

Two hundred and fifty-six patient with stroke and caregiver dyads (N = 512) were analysed, with patients having spouse (60%), child (29%), sibling (4%) and other (7%) as their caregivers. Among all participants, 89% of index strokes were ischemic, 57% were mild in severity and more than half (59%) of the patients had moderate or severe disability post-stroke as measured on the Modified Rankin Scale. Having social support in the form of a foreign domestic worker for general help of caregiver reduced the hospitalization rate over 3 months post-stroke by 66% (IRR: 0.342; 95% CI: 0.180, 0.651). Compared to having a spousal caregiver, those with a child caregiver had an almost three times greater rate of hospitalizations over 3–12 months post-stroke (IRR: 2.896; 95% CI: 1.399, 5.992). Higher reported caregiving burden at the 3-month point was associated with the higher subsequent rate of hospitalization.

Conclusion

Recommendations include the adoption of a dyadic or holistic approach to post-stroke care provision by healthcare practitioners, giving due importance to both patients with stroke and their caregivers, integrating caregivers in the healthcare system to extend the care continuum to include informal care in the community and provision of timely support for caregivers.

Pre-discharge prognostic factors of physical function among older adults with hip fracture surgery: a systematic review

INTRODUCTION

To identify, organize, and assess the evidence level of pre-discharge prognostic factors of physical function beyond discharge after hip fracture surgery.

METHODS

We performed a systematic search of four databases (PubMed, Embase, CINAHL, PsycINFO) for longitudinal studies of prognostic factors of physical function at ≥ 1 month among older adults ≥ 50 years old with surgically treated hip fracture, complemented with hand-searching. Two reviewers independently screened papers for inclusion and assessed the quality of all the included papers using the Quality in Prognosis Studies (QUIPS) tool. We assigned the evidence level for each prognostic factor based on consistency in findings and study quality.

RESULTS

From 98 papers that met our inclusion criteria, we identified 107 pre-discharge prognostic factors and organized them into the following seven categories: demographic, physical, cognitive, psychosocial, socioeconomic, injury-related, and process of care. Potentially modifiable factors with strong or moderate evidence of an association included total length of stay, physical function at discharge, and grip strength. Factors with strong or moderate evidence of no association included gender, fracture type, and time to surgery. Factors with limited, conflicting, or inconclusive evidence included body-mass index, psychological resilience, depression, and anxiety.

CONCLUSIONS

Our findings highlight potentially modifiable prognostic factors that could be targeted and non-modifiable prognostic factors that could be used to identify patients who may benefit from more intensive intervention or to advise patients on their expectations on recovery. Examining the efficacies of existing interventions targeting these prognostic factors would inform future studies and whether any of such interventions could be incorporated into clinical practice.

Physical Performance Predictor Measures in Older Adults With Falls-Related Emergency Department Visits

OBJECTIVES

Identifying strong predictors for falls and mobility limitations in older adults with a falls-related emergency department visit is crucial. This study aimed to compare, in this clinical population, the incremental predictive value of the Short Physical Performance Battery (SPPB) component tests for incident falls, injurious falls, and mobility limitations.

DESIGN AND MEASURES

Prospective cohort study.

SETTING AND PARTICIPANTS

A total of 323 community-dwelling older adults with a falls-related emergency department visit participated. Baseline physical performance was measured by the SPPB standing balance test, sit-to-stand test, and habitual gait speed test. Six-month prospective fall rate and self-reported mobility limitations at 6 months post baseline assessment were also measured. An injurious fall was defined as a fall for which the participant sought medical attention or that restricted his or her daily activities for at least 48 hours.

RESULTS

In multivariable proportional odds analyses adjusted for demographics and clinical covariates, higher levels of full-tandem balance and sit-to-stand performance were significantly associated with fewer incident falls (P = .04 and .02, respectively) and lower odds of mobility limitations (P = .05 and .03, respectively) and marginally associated with lower odds of injurious falls (P = .06 and .07, respectively). Habitual gait speed was the weakest predictor of falls but the strongest predictor (odds ratio 0.24, 95% confidence interval 0.08-0.70; P < .001) of mobility limitations.

CONCLUSIONS/IMPLICATIONS

In high-fall-risk older adults, the SPPB balance and sit-to-stand tests predicted falls whereas the SPPB gait speed test was adept at predicting mobility limitations. No one test is best across all situations, so the choice of test will depend on the goal of the assessment.

Systems modelling as an approach for understanding and building consensus on non-communicable diseases (NCD) management in Cambodia

Background

This paper aims to demonstrate how systems modeling methodology of Group Model Building (GMD) can be applied for exploring and reaching consensus on non-communicable disease (NCD) management. This exercise was undertaken as a first step for developing a quantitative simulation model for generating credible estimates to make an investment case for the prevention and management of NCDs.

Methods

Stakeholder engagement was facilitated through the use of a Group Model Building (GMB) approach. This approach combines various techniques in order to gain a whole system perspective.

Results

A conceptual qualitative model framework that connects prevention—via risk factors reduction—screening and treatment of non-communicable diseases (NCDs) was developed with stakeholders that draws on stakeholders personal experiences, beliefs, and perceptions through a moderated interactions to gain in-depth understanding of NCDs management.

Conclusion

Managing NCDs in Cambodia will require concerted effort to tackle NCD risk factors, identifying individuals with NCDs through screening and providing adequate and affordable consistent care to improve health and outcomes of NCDs.

Making Clinical Practice Guidelines Pragmatic: How Big Data and Real World Evidence Can Close the Gap

Clinical practice guidelines (CPGs) have become ubiquitous in every field of medicine today but there has been limited success in implementation and improvement in health outcomes. Guidelines are largely based on the results of traditional randomised controlled trials (RCTs) which adopt a highly selective process to maximise the intervention's chance of demonstrating efficacy thus having high internal validity but lacking external validity. Therefore, guidelines based on these RCTs often suffer from a gap between trial efficacy and real world effectiveness and is one of the common reasons contributing to poor guideline adherence by physicians. "Real World Evidence" (RWE) can complement RCTs in CPG development. RWE-in the form of data from integrated electronic health records-represents the vast and varied collective experience of frontline doctors and patients. RWE has the potential to fill the gap in current guidelines by balancing information about whether a test or treatment works (efficacy) with data on how it works in real world practice (effectiveness). RWE can also advance the agenda of precision medicine in everyday practice by engaging frontline stakeholders in pragmatic biomarker studies. This will enable guideline developers to more precisely determine not only whether a clinical test or treatment is recommended, but for whom and when. Singapore is well positioned to ride the big data and RWE wave as we have the advantages of high digital interconnectivity, an integrated National Electronic Health Record (NEHR), and governmental support in the form of the Smart Nation initiative.

Healthcare utilization and cost trajectories post-stroke: role of caregiver and stroke factors

BACKGROUND

It is essential to study post-stroke healthcare utilization trajectories from a stroke patient caregiver dyadic perspective to improve healthcare delivery, practices and eventually improve long-term outcomes for stroke patients. However, literature addressing this area is currently limited. Addressing this gap, our study described the trajectory of healthcare service utilization by stroke patients and associated costs over 1-year post-stroke and examined the association with caregiver identity and clinical stroke factors.

METHODS

Patient and caregiver variables were obtained from a prospective cohort, while healthcare data was obtained from the national claims database. Generalized estimating equation approach was used to get the population average estimates of healthcare utilization and cost trend across 4 quarters post-stroke.

RESULTS

Five hundred ninety-two stroke patient and caregiver dyads were available for current analysis. The highest utilization occurred in the first quarter post-stroke across all service types and decreased with time. The incidence rate ratio (IRR) of hospitalization decreased by 51, 40, 11 and 1% for patients having spouse, sibling, child and others as caregivers respectively when compared with not having a caregiver (p = 0.017). Disability level modified the specialist outpatient clinic usage trajectory with increasing difference between mildly and severely disabled sub-groups across quarters. Stroke type and severity modified the primary care cost trajectory with expected cost estimates differing across second to fourth quarters for moderately-severe ischemic (IRR: 1.67, 1.74, 1.64; p = 0.003), moderately-severe non-ischemic (IRR: 1.61, 3.15, 2.44; p = 0.001) and severe non-ischemic (IRR: 2.18, 4.92, 4.77; p = 0.032) subgroups respectively, compared to first quarter.

CONCLUSION

Highlighting the quarterly variations, we reported distinct utilization trajectories across subgroups based on clinical characteristics. Caregiver availability reducing hospitalization supports revisiting caregiver's role as potential hidden workforce, incentivizing their efforts by designing socially inclusive bundled payment models for post-acute stroke care and adopting family-centered clinical care practices.

Can caregivers report their care recipients' post-stroke hospitalizations and outpatient visits accurately? Findings of an Asian prospective stroke cohort

Background

Health services research aimed at understanding service use and improving resource allocation often relies on collecting subjectively reported or proxy-reported healthcare service utilization (HSU) data. It is important to know the discrepancies in such self or proxy reports, as they have significant financial and policy implications. In high-dependency populations, such as stroke survivors, with varying levels of cognitive impairment and dysphasia, caregivers are often potential sources of stroke survivors’ HSU information. Most of the work conducted on agreement analysis to date has focused on validating different sources of self-reported data, with few studies exploring the validity of caregiver-reported data. Addressing this gap, our study aimed to quantify the agreement across the caregiver-reported and national claims-based HSU of stroke patients.

Methods

A prospective study comprising multi-ethnic stroke patient and caregiver dyads (N = 485) in Singapore was the basis of the current analysis, which used linked national claims records. Caregiver-reported health services data were collected via face-to-face and telephone interviews, and similar health services data were extracted from the national claims records. The main outcome variable was the modified intraclass correlation coefficient (ICC), which provided the level of agreement across both data sources. We further identified the amount of over- or under-reporting by caregivers across different service types.

Results

We observed variations in agreement for different health services, with agreement across caregiver reports and national claims records being the highest for outpatient visits (specialist and primary care), followed by hospitalizations and emergency department visits. Interestingly, caregivers over-reported hospitalizations by approximately 49% and under-reported specialist and primary care visits by approximately 20 to 30%.

Conclusions

The accuracy of the caregiver-reported HSU of stroke patients varies across different service types. Relatively more objective data sources, such as national claims records, should be considered as a first choice for quantifying health care usage before considering caregiver-reported usage. Caregiver-reported outpatient service use was relatively more accurate than inpatient service use over shorter recall periods. Therefore, in situations where objective data sources are limited, caregiver-reported outpatient information can be considered for low volumes of healthcare consumption, using an appropriate correction to account for potential under-reporting.

Electronic supplementary material

The online version of this article (10.1186/s12913-018-3634-4) contains supplementary material, which is available to authorized users.

Trajectories of functional ability over the life course: a conceptual model of the interaction of stressor-induced functional loss and resilience

Understanding the factors that influence functional ability over the life course is integral to identifying clinical and public health policies to facilitate successful aging. The World Health Organization has advocated a conceptual framework to clarify the policy discussion. We have sought to translate this general framework into an explicit system dynamics model of the interaction of physiological loss, stressors and endogenous responses to produce a familiar variety of trajectories of functional ability over the life courses. Simulation experiments were implemented for both a 30-month duration with only one major stressor; and for the life course with an initial major stressor and subsequent stressors determined by the level of functional ability. For both contexts, variations in the few parameters in the scenarios led to a realistic range of trajectories of function over time.

Triaging Primary Care Patients Referred for Chest Pain to Specialist Cardiology Centres: Efficacy of an Optimised Protocol

INTRODUCTION

Patients referred for chest pain from primary care have increased, along with demand for outpatient cardiology consultations. We evaluated 'Triage Protocol' that implements standardised diagnostic testing prior to patients' first cardiology consultation.

MATERIALS AND METHODS

Under the 'Triage Protocol', patients referred for chest pain were pretriaged using a standardised algorithm and subsequently referred for relevant functional diagnostic cardiology tests before their initial cardiology consultation. At the initial cardiology consultation scheduled by the primary care provider, test results were reviewed. A total of 522 triage patients (mean age 55 ± 13, male 53%) were frequency-matched by age, gender and risk cohort to 289 control patients (mean age: 56 ± 11, male: 52%). Pretest risk of coronary artery disease was defined according to a Modified Duke Clinical Score (MDCS) as low (<10), intermediate (10-20) and high (>20). The primary outcome was time from referral to diagnosis (days). Secondary outcomes were total visits, discharge rate at first consultation, patient cost and adverse cardiac outcomes.

RESULTS

The 'Triage Protocol' resulted in shorter times from referral to diagnosis (46 vs 131 days; P <0.0001) and fewer total visits (2.4 vs 3.0; P <0.0001). However, triage patients in low-risk groups experienced higher costs due to increased testing (S$421 vs S$357, P = 0.003). Adverse cardiac event rates under the 'Triage Protocol' indicated no compromise to patient safety (triage vs control: 0.57% vs 0.35%; P = 1.000).

CONCLUSION

By implementing diagnostic cardiac testing prior to patients' first specialist consultation, the 'Triage Protocol' expedited diagnosis and reduced subsequent visits across all risk groups in ambulatory chest pain patients.

Projection of Eye Disease Burden in Singapore

INTRODUCTION

Singapore's ageing population is likely to see an increase in chronic eye conditions in the future. This study aimed to estimate the burden of eye diseases among resident Singaporeans stratified for age and ethnicity by 2040.

MATERIALS AND METHODS

Prevalence data on myopia, epiretinal membrane (ERM), retinal vein occlusion (RVO), age macular degeneration (AMD), diabetic retinopathy (DR), cataract, glaucoma and refractive error (RE) by age cohorts and educational attainment from the Singapore Epidemiology of Eye Diseases (SEED) study were applied to population estimates from the Singapore population model.

RESULTS

All eye conditions are projected to increase by 2040. Myopia and RE will remain the most prevalent condition, at 2.393 million (2.32 to 2.41 million) cases, representing a 58% increase from 2015. It is followed by cataract and ERM, with 1.33 million (1.31 to 1.35 million), representing an 81% increase, and 0.54 million (0.53 to 0.549 million) cases representing a 97% increase, respectively. Eye conditions that will see the greatest increase from 2015 to 2040 in the Chinese are: DR (112%), glaucoma (100%) and ERM (91.4%). For Malays, DR (154%), ERM (136%), and cataract (122%) cases are expected to increase the most while for Indians, ERM (112%), AMD (101%), and cataract (87%) are estimated to increase the most in the same period.

CONCLUSION

Results indicate that the burden for all eye diseases is expected to increase significantly into the future, but at different rates. These projections can facilitate the planning efforts of both policymakers and healthcare providers in the development and provision of infrastructure and resources to adequately meet the eye care needs of the population. By stratifying for age and ethnicity, high risk groups may be identified and targeted interventions may be implemented.

Randomized Controlled Trial of Screening, Risk Modification, and Physical Therapy to Prevent Falls Among the Elderly Recently Discharged From the Emergency Department to the Community: The Steps to Avoid Falls in the Elderly Study

OBJECTIVE

To evaluate the effectiveness of a multifactorial, tailored program of physical therapy to reduce the occurrence of falls among a heterogeneous group of high-risk elderly Singaporeans recently discharged from the emergency department (ED).

DESIGN

Randomized controlled trial.

SETTING

Communities.

PARTICIPANTS

Adults (N=354) aged ≥65 years who were seen in the ED for a fall or fall-related injuries and discharged home.

INTERVENTIONS

The intervention primarily consisted of a tailored program of physical therapy focused on progressive training in strength, balance, and gait for a period of 3 months. Participants in the intervention group also received screening and follow-up for vision, polypharmacy, and environmental hazards. Participants in the control group received usual care prescribed by a physician and educational materials on falls prevention.

MAIN OUTCOME MEASURES

The primary outcome measure was experiencing at least 1 fall during the 9-month study period (a 3-mo active intervention phase and a 6-mo maintenance phase). Secondary outcome measures were the occurrence of at least 1 injurious fall during the study period and a change in the Short Physical Performance Battery (SPPB) score. Participants were assessed both after 3 and 9 months.

RESULTS

During the 9-month study period, 37.8% of the control group and 30.5% of the intervention group fell at least once, which was not statistically significantly different (odds ratio [OR]=.72; 95% confidence interval [CI], .46-1.12; P=.146). The intervention group had statistically significantly fewer individuals with injurious falls (OR=.56; 95% CI, .32-.98; P=.041) and less deterioration in physical performance, reflected by a mean difference of 0.6 in SPPB scores (P=.029). Multivariate analyses indicated a strong interaction effect between the intervention and the presence of 2 or more major comorbidities; after accounting for this effect, the intervention program reduced the number of people experiencing at least 1 fall (OR=.34; 95% CI, .17-.67; P=.002).

CONCLUSIONS

We observed that in this heterogeneous population, the proportion of participants experiencing at least 1 fall during the study period was not statistically significantly lower in the intervention group compared with the control group. Secondary analyses strongly suggest that individuals with 2 or more major comorbidities do not benefit from a tailored physical therapy program; however, individuals with less comorbidity may substantially benefit.

Serum Cholesterol Levels within the High Normal Range Are Associated with Better Cognitive Performance among Chinese Elderly

OBJECTIVES

The association between cognitive function and cholesterol levels is poorly understood and inconsistent results exist among the elderly. The purpose of this study is to investigate the association of cholesterol level with cognitive performance among Chinese elderly.

DESIGN

A cross-sectional study was implemented in 2012 and data were analyzed using generalized additive models, linear regression models and logistic regression models.

SETTING

Community-based setting in eight longevity areas in China.

SUBJECTS

A total of 2000 elderly aged 65 years and over (mean 85.8±12.0 years) participated in this study.

MEASUREMENTS

Total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) concentration were determined and cognitive impairment was defined as Mini-Mental State Examination (MMSE) score ≤23.

RESULTS

There was a significant positive linear association between TC, TG, LDL-C, HDL-C and MMSE score in linear regression models. Each 1 mmol/L increase in TC, TG, LDL-C and HDL-C corresponded to a decreased risk of cognitive impairment in logistic regression models. Compared with the lowest tertile, the highest tertile of TC, LDL-C and HDL-C had a lower risk of cognitive impairment. The adjusted odds ratios and 95% CI were 0.73(0.62-0.84) for TC, 0.81(0.70-0.94) for LDL-C and 0.81(0.70-0.94) for HDL-C. There was no gender difference in the protective effects of high TC and LDL-C levels on cognitive impairment. However, for high HDL-C levels the effect was only observed in women. High TC, LDL-C and HDL-C levels were associated with lower risk of cognitive impairment in the oldest old (aged 80 and older), but not in the younger elderly (aged 65 to 79 years).

CONCLUSIONS

These findings suggest that cholesterol levels within the high normal range are associated with better cognitive performance in Chinese elderly, specifically in the oldest old. With further validation, low cholesterol may serve a clinical indicator of risk for cognitive impairment in the elderly.

Emergency department crowding in Singapore: Insights from a systems thinking approach

Objectives:

Emergency Department crowding is a serious and international health care problem that seems to be resistant to most well intended but often reductionist policy approaches. In this study, we examine Emergency Department crowding in Singapore from a systems thinking perspective using causal loop diagramming to visualize the systemic structure underlying this complex phenomenon. Furthermore, we evaluate the relative impact of three different policies in reducing Emergency Department crowding in Singapore: introduction of geriatric emergency medicine, expansion of emergency medicine training, and implementation of enhanced primary care.

Methods:

The construction of the qualitative causal loop diagram is based on consultations with Emergency Department experts, direct observation, and a thorough literature review. For the purpose of policy analysis, a novel approach, the path analysis, is applied.

Results:

The path analysis revealed that both the introduction of geriatric emergency medicine and the expansion of emergency medicine training may be associated with undesirable consequences contributing to Emergency Department crowding. In contrast, enhancing primary care was found to be germane in reducing Emergency Department crowding; in addition, it has apparently no negative side effects, considering the boundary of the model created.

Conclusion:

Causal loop diagramming was a powerful tool for eliciting the systemic structure of Emergency Department crowding in Singapore. Additionally, the developed model was valuable in testing different policy options.

At-Home Versus In-Clinic INR Monitoring: A Cost-Utility Analysis from The Home INR Study (THINRS)

BACKGROUND

Effective management of patients using warfarin is resource-intensive, requiring frequent in-clinic testing of the international normalized ratio (INR). Patient self-testing (PST) using portable at-home INR monitoring devices has emerged as a convenient alternative. As revealed by The Home INR Study (THINRS), event rates for PST were not significantly different from those for in-clinic high-quality anticoagulation management (HQACM), and a cumulative gain in quality of life was observed for patients undergoing PST.

OBJECTIVE

To perform a cost-utility analysis of weekly PST versus monthly HQACM and to examine the sensitivity of these results to testing frequency.

PATIENTS/INTERVENTIONS

In this study, 2922 patients taking warfarin for atrial fibrillation or mechanical heart valve, and who demonstrated PST competence, were randomized to either weekly PST (n = 1465) or monthly in-clinic testing (n = 1457). In a sub-study, 234 additional patients were randomized to PST once every 4 weeks (n = 116) or PST twice weekly (n = 118). The endpoints were quality of life (measured by the Health Utilities Index), health care utilization, and costs over 2 years of follow-up.

RESULTS

PST and HQACM participants were similar with regard to gender, age, and CHADS2 score. The total cost per patient over 2 years of follow-up was $32,484 for HQACM and $33,460 for weekly PST, representing a difference of $976. The incremental cost per quality-adjusted life year gained with PST once weekly was $5566 (95 % CI, -$11,490 to $25,142). The incremental cost-effectiveness ratio (ICER) was sensitive to testing frequency: weekly PST dominated PST twice weekly and once every 4 weeks. Compared to HQACM, weekly PST was associated with statistically significant and clinically meaningful improvements in quality of life. The ICER for weekly PST versus HQACM was well within accepted standards for cost-effectiveness, and was preferred over more or less frequent PST. These results were robust to sensitivity analyses of key assumptions.

CONCLUSION

Weekly PST is a cost-effective alternative to monthly HQACM and a preferred testing frequency compared to twice weekly or monthly PST.

Vitamin D Levels and the Risk of Cognitive Decline in Chinese Elderly People: the Chinese Longitudinal Healthy Longevity Survey

BACKGROUND

Vitamin D has a neuroprotective function, potentially important for the prevention of cognitive decline. Prospective studies from Western countries support an association between lower vitamin D level and future cognitive decline in elderly people. No prospective study has examined this association in Asia.

METHODS

This community-based cohort study of elderly people in China follows 1,202 cognitively intact adults aged ≥60 years for a mean duration of 2 years. Plasma vitamin D level was measured at the baseline. Cognitive state of participants was assessed using the Mini-Mental State Examination (MMSE). Cognitive impairment was defined as an MMSE score <18. Cognitive decline was defined as ≥3 points decline from baseline. Multivariable logistic regression models were used to examine the association between quartiles of vitamin D levels with cognitive decline and incidence of cognitive impairment.

RESULTS

Participants with low vitamin D level had an increased risk of cognitive decline. Compared with the highest quartile of vitamin D levels, the multivariable odds ratios (ORs; 95% confidence interval) for cognitive decline were 2.1 (1.3-3.4) for the second highest quartile, 2.2 (1.4-3.6) for the third highest quartile, and 2.0 (1.2-3.3) for the lowest quartile. The multivariable ORs of incident cognitive impairment for the second highest, third highest, and lowest versus highest quartiles of vitamin D levels were 1.9 (0.9-4.1), 2.6 (1.2-5.6), and 3.2 (1.5-6.6), respectively.

CONCLUSIONS

This first follow-up study of elderly people, including the oldest-old, in Asia shows that low vitamin D levels were associated with increased risk of subsequent cognitive decline and impairment.

Cost of multiple sclerosis by level of disability: a review of literature

We performed a review of the economic literature to identify what is known about the relationship between Expanded Disability Status Scale (EDSS) categories and cost of multiple sclerosis (MS). We sought cohort studies of patients with multiple sclerosis that described the costs attributed to each EDSS score and utilized specific inclusion criteria for the selection of 10 studies. We found that both direct and indirect costs rise continuously with increasing EDSS category, and this rise is qualitatively exponential. The rise in indirect costs appears at lower EDSS scores. The cost of a relapse occurring in any given EDSS category exceeds that associated with that particular EDSS category. Few studies comprehensively assessed the entire spectrum of the costs, and much of the literature is based on EDSS categories in coarse groupings. In spite of several variations between studies, one important conclusion that we can draw is that rise in cost is positively correlated to scores on the EDSS categories, and therefore agents with a capacity to prevent or arrest the rate of MS progression may affect the overall cost of MS.

Linked Sensitivity Analysis, Calibration, and Uncertainty Analysis Using a System Dynamics Model for Stroke Comparative Effectiveness Research

BACKGROUND

As health services researchers and decision makers tackle more difficult problems using simulation models, the number of parameters and the corresponding degree of uncertainty have increased. This often results in reduced confidence in such complex models to guide decision making.

OBJECTIVE

To demonstrate a systematic approach of linked sensitivity analysis, calibration, and uncertainty analysis to improve confidence in complex models.

METHODS

Four techniques were integrated and applied to a System Dynamics stroke model of US veterans, which was developed to inform systemwide intervention and research planning: Morris method (sensitivity analysis), multistart Powell hill-climbing algorithm and generalized likelihood uncertainty estimation (calibration), and Monte Carlo simulation (uncertainty analysis).

RESULTS

Of 60 uncertain parameters, sensitivity analysis identified 29 needing calibration, 7 that did not need calibration but significantly influenced key stroke outcomes, and 24 not influential to calibration or stroke outcomes that were fixed at their best guess values. One thousand alternative well-calibrated baselines were obtained to reflect calibration uncertainty and brought into uncertainty analysis. The initial stroke incidence rate among veterans was identified as the most influential uncertain parameter, for which further data should be collected. That said, accounting for current uncertainty, the analysis of 15 distinct prevention and treatment interventions provided a robust conclusion that hypertension control for all veterans would yield the largest gain in quality-adjusted life years.

CONCLUSIONS

For complex health care models, a mixed approach was applied to examine the uncertainty surrounding key stroke outcomes and the robustness of conclusions. We demonstrate that this rigorous approach can be practical and advocate for such analysis to promote understanding of the limits of certainty in applying models to current decisions and to guide future data collection.

Prevalence and Risk Factors of Atrial Fibrillation in Chinese Elderly: Results from the Chinese Longitudinal Healthy Longevity Survey

BACKGROUND

Prevalence of atrial fibrillation (AF) is increasing as the world ages. AF is associated with higher risk of mortality and disease, including stroke, hypertension, heart failure, and dementia. Prevalence of AF differs with each population studied, and research on non-Western populations and the oldest old is scarce.

METHODS

We used data from the 2012 wave of the Chinese Longitudinal Healthy Longevity Survey, a community-based study in eight longevity areas in China, to estimate AF prevalence in an elderly Chinese population (n = 1418, mean age = 85.6 years) and to identify risk factors. We determined the presence of AF in our participants using single-lead electrocardiograms. The weighted prevalence of AF was estimated in subjects stratified according to age groups (65-74, 75-84, 85-94, 95 years and above) and gender. We used logistic regressions to determine the potential risk factors of AF.

RESULTS

The overall prevalence of AF was 3.5%; 2.4% of men and 4.5% of women had AF (P < 0.05). AF was associated with weight extremes of being underweight or overweight/obese. Finally, advanced age (85-94 years), history of stroke or heart disease, low high-density lipoprotein levels, low triglyceride levels, and lack of regular physical activity were associated with AF.

CONCLUSIONS

In urban elderly, AF prevalence increased with age (P < 0.05), and in rural elderly, women had higher AF prevalence (P < 0.05). Further exploration of population-specific risk factors is needed to address the AF epidemic.

Projecting the effects of long-term care policy on the labor market participation of primary informal family caregivers of elderly with disability: insights from a dynamic simulation model

Background

Using Singapore as a case study, this paper aims to understand the effects of the current long-term care policy and various alternative policy options on the labor market participation of primary informal family caregivers of elderly with disability.

Methods

A model of the long-term care system in Singapore was developed using System Dynamics methodology.

Results

Under the current long-term care policy, by 2030, 6.9 percent of primary informal family caregivers (0.34 percent of the domestic labor supply) are expected to withdraw from the labor market. Alternative policy options reduce primary informal family caregiver labor market withdrawal; however, the number of workers required to scale up long-term care services is greater than the number of caregivers who can be expected to return to the labor market.

Conclusions

Policymakers may face a dilemma between admitting more foreign workers to provide long-term care services and depending on primary informal family caregivers.

Electronic supplementary material

The online version of this article (doi:10.1186/s12877-016-0243-0) contains supplementary material, which is available to authorized users.

Cost Effectiveness of Universal Hepatitis B Virus Screening in Patients Beginning Chemotherapy for Sarcomas or GI Stromal Tumors

PURPOSE

The value of screening for hepatitis B virus (HBV) infection before chemotherapy for nonhematopoietic solid tumors remains unsettled. We evaluated the cost effectiveness of universal screening before systemic therapy for sarcomas, including GI stromal tumors (GISTs).

PATIENTS AND METHODS

Drawing from the National Cancer Centre Singapore database of 1,039 patients with sarcomas, we analyzed the clinical records of 485 patients who received systemic therapy. Using a Markov model, we compared the cost effectiveness of a screen-all versus screen-none strategy in this population.

RESULTS

A total of 237 patients were screened for HBV infection. No patients developed HBV reactivation during chemotherapy. The incremental cost-effectiveness ratio per quality-adjusted life-year (QALY) of offering HBV screening to all patients with sarcomas and patients with GISTs exceeded the cost-effectiveness threshold of SG$100,000 per QALY. This result was robust in one-way sensitivity analysis. Our results show that only changes in mortality rate secondary to HBV reactivation could make the incremental cost-effectiveness ratio cross the cost-effectiveness threshold.

CONCLUSION

Universal HBV screening in patients with sarcomas or GISTs undergoing chemotherapy is not cost effective at a willingness to pay of SG$100,000 per QALY and may not be required.

Does distance modify the effect of self-testing in oral anticoagulation?

OBJECTIVES

Patient self-testing (PST) improves anticoagulation control and patient satisfaction. It is unknown whether these effects are more pronounced when the patient lives farther from the anticoagulation clinic (ACC). If the benefits of PST are limited to a subset of patients (those living farther from care), selectively providing PST to that subset could enhance cost-effectiveness.

STUDY DESIGN

This is a secondary analysis of a randomized trial of PST versus usual ACC care, which involved 2922 patients of the Veterans Health Administration (VHA).

METHODS

Our 3 outcomes were the primary composite clinical end point (stroke, major hemorrhage, or death), anticoagulation control (percent time in therapeutic range), and satisfaction with anticoagulation care. We measured the driving distance between the patient's residence and the nearest VHA facility. We divided patients into quartiles by distance and looked for evidence of an interaction between distance and the effect of the intervention on the 3 outcomes.

RESULTS

The median driving distance was 12 miles (interquartile range = 6-21). Patients living in the farthest quartile had higher rates of the primary composite clinical end point in both groups compared with patients living in the nearest quartile. For PST, the hazard ratio (HR) was 1.77 (95% CI, 1.18-2.64), and for usual care, the HR was 1.81 (95% CI, 1.19-2.75). Interaction terms did not suggest that distance to care modified the effect of the intervention on any outcome.

CONCLUSIONS

The benefits of PST were not enhanced among patients living farther from care. Restricting PST to patients living more than a certain distance from the ACC is not likely to improve its cost-effectiveness.

Future requirements for and supply of ophthalmologists for an aging population in Singapore

BACKGROUND

Singapore's population, as that of many other countries, is aging; this is likely to lead to an increase in eye diseases and the demand for eye care. Since ophthalmologist training is long and expensive, early planning is essential. This paper forecasts workforce and training requirements for Singapore up to the year 2040 under several plausible future scenarios.

METHODS

The Singapore Eye Care Workforce Model was created as a continuous time compartment model with explicit workforce stocks using system dynamics. The model has three modules: prevalence of eye disease, demand, and workforce requirements. The model is used to simulate the prevalence of eye diseases, patient visits, and workforce requirements for the public sector under different scenarios in order to determine training requirements.

RESULTS

Four scenarios were constructed. Under the baseline business-as-usual scenario, the required number of ophthalmologists is projected to increase by 117% from 2015 to 2040. Under the current policy scenario (assuming an increase of service uptake due to increased awareness, availability, and accessibility of eye care services), the increase will be 175%, while under the new model of care scenario (considering the additional effect of providing some services by non-ophthalmologists) the increase will only be 150%. The moderated workload scenario (assuming in addition a reduction of the clinical workload) projects an increase in the required number of ophthalmologists of 192% by 2040. Considering the uncertainties in the projected demand for eye care services, under the business-as-usual scenario, a residency intake of 8-22 residents per year is required, 17-21 under the current policy scenario, 14-18 under the new model of care scenario, and, under the moderated workload scenario, an intake of 18-23 residents per year is required.

CONCLUSIONS

The results show that under all scenarios considered, Singapore's aging and growing population will result in an almost doubling of the number of Singaporeans with eye conditions, a significant increase in public sector eye care demand and, consequently, a greater requirement for ophthalmologists.

International Comparison of Poststroke Resource Use: A Longitudinal Analysis in Europe

BACKGROUND

Long-term costs often represent a large proportion of the total costs induced by stroke, but data on long-term poststroke resource use are sparse, especially regarding the trajectory of costs by severity. We used a multinational longitudinal survey to estimate patterns of poststroke resource use by degree of functional disability and to compare resource use between regions.

METHODS

The Survey of Health, Ageing and Retirement in Europe (SHARE) is a multinational database of adults 50 years and older, which includes demographic information about respondents, age when stroke first occurred, current activity of daily living (ADL) limitations, and health care resource use in the year before interview. We modeled resource use with a 2-part regression for number of hospital days, home nursing hours, and paid and unpaid home caregiving hours.

RESULTS

After accounting for time since stroke, number of strokes and comorbidities, age, gender, and European regions, we found that poststroke resource use was strongly associated with ADL limitations. The duration since the stroke event was significantly associated only with inpatient care, and informal help showed significant regional heterogeneity across all ADL limitation levels.

CONCLUSIONS

Poststroke physical deficits appear to be a strong driver of long-term resource utilization; treatments that decrease such deficits offer substantial potential for downline cost savings. Analyzing internationally comparable panel data, such as SHARE, provide valuable insight into long-term cost of stroke. More comprehensive international comparisons will require registries with follow-up, particularly for informal and formal home-based care.