The prevalence patterns and risk factor profiles of poor muscle health and its associated components in multiethnic older Asians: The PIONEER study

BACKGROUND

We aim to determine the multiethnic patterns of the prevalence and associated factors of poor muscle health and its associated components in older Chinese, Malays, and Indian Asian adults.

METHODS

We included 2199 participants (mean age ± SD: 72.9 ± 8.3 years; 54.3% female) from the baseline assessment of the Population Health and Eye Disease Profile in Elderly Singaporeans (PIONEER; 2017-2022) cohort study. Poor muscle health was defined as the presence of either low muscle mass (DEXA), or low muscle strength (handgrip strength), or low physical performance (gait speed). Its components include poor muscle function (low muscle strength and/or low physical performance without low muscle mass), pre-sarcopenia (low muscle mass only), and any sarcopenia (low muscle mass with low muscle strength and/or low physical performance). Sociodemographic, clinical, and lifestyle factors were assessed using biochemistry, clinical tests, and validated questionnaires. Regression models were utilized to evaluate the independent risk factors of poor muscle health and its components.

RESULTS

The national census-adjusted prevalence of poor muscle health (88%) was similar across the three ethnic groups. However, Chinese individuals had higher prevalence of pre-sarcopenia and any sarcopenia, and a lower prevalence of poor muscle function compared with Indians or Malays. We observed ethnic differences in modifiable risk factors (low physical activity, diabetes, osteoporosis, and obesity) of poor muscle health and its components. Although obesity was protective of pre-sarcopenia (RRR = 0.19, 95% CI: 0.11, 0.36) and any sarcopenia (RRR = 0.29, 95% CI: 0.18, 0.47) in the overall population and across ethnic groups, it was associated with 1.7 times (95% CI: 1.07, 2.67) the likelihood of poor muscle function in the entire population.

CONCLUSIONS

Almost 90% of community dwelling Singaporean aged ≥60 years have poor muscle health across the three ethnic groups with ethnic disparities in modifiable risk factors, highlighting an urgent need for community-wide targeted interventions to promote muscle health.

Prevalence, associated risk factors; and patient and economic impact of multiple sensory impairment in a multi-ethnic elderly population in Singapore: the PIONEER study

BACKGROUND

To determine the prevalence, risk factors; and impact on patient health and economic outcomes across the laterality spectrum of multiple sensory impairment (MSI) in a multi-ethnic older Asian population.

METHODS

In this population-based study of Singaporeans aged ≥ 60 years, MSI was defined as concomitant vision (visual acuity > 0.3 logMAR), hearing (pure-tone air conduction average > 25 dB), and olfactory (score < 12 on the Sniffin' Sticks test) impairments across the spectrum of laterality (any, unilateral, combination [of unilateral and bilateral], and bilateral).

RESULTS

Among 2,057 participants (mean ± SD 72.2 ± 0.2 years; 53.1% female), the national census-adjusted prevalence rates of any, unilateral, combination, and bilateral MSI were 20.6%, 1.2%, 12.2%, and 7.2%, respectively. Older age, male gender, low socioeconomic status (SES), and smoking (all p < 0.05) were independently associated with higher likelihood of any MSI. Compared to those with no sensory loss, those with MSI had significantly decreased mobility (range 5.4%-9.2%), had poor functioning (OR range 3.25-3.45) and increased healthcare costs (range 4-6 folds) across the laterality spectrum. Additionally, bilateral MSI had a significant decrease in HRQoL (5.5%, p = 0.012).

CONCLUSIONS

MSI is a highly prevalent medical condition, with 1 in 5; and almost 1 in 10 community-dwelling older Asians having any and bilateral MSI, respectively, with a higher likelihood in men, smokers, and those with low SES. Critically, MSI has a substantial negative impact on patient health and economic outcomes across the laterality spectrum. Sensory testing is critical to detect and refer individuals with MSI for management to improve their functional independence and QoL.

Extending the diabetic retinopathy screening intervals in Singapore: methodology and preliminary findings of a cohort study

BACKGROUND

The Diabetic Retinopathy Extended Screening Study (DRESS) aims to develop and validate a new DR/diabetic macular edema (DME) risk stratification model in patients with Type 2 diabetes (DM) to identify low-risk groups who can be safely assigned to biennial or triennial screening intervals. We describe the study methodology, participants' baseline characteristics, and preliminary DR progression rates at the first annual follow-up.

METHODS

DRESS is a 3-year ongoing longitudinal study of patients with T2DM and no or mild non-proliferative DR (NPDR, non-referable) who underwent teleophthalmic screening under the Singapore integrated Diabetic Retinopathy Programme (SiDRP) at four SingHealth Polyclinics. Patients with referable DR/DME (> mild NPDR) or ungradable fundus images were excluded. Sociodemographic, lifestyle, medical and clinical information was obtained from medical records and interviewer-administered questionnaires at baseline. These data are extracted from medical records at 12, 24 and 36 months post-enrollment. Baseline descriptive characteristics stratified by DR severity at baseline and rates of progression to referable DR at 12-month follow-up were calculated.

RESULTS

Of 5,840 eligible patients, 78.3% (n = 4,570, median [interquartile range [IQR] age 61.0 [55-67] years; 54.7% male; 68.0% Chinese) completed the baseline assessment. At baseline, 97.4% and 2.6% had none and mild NPDR (worse eye), respectively. Most participants had hypertension (79.2%) and dyslipidemia (92.8%); and almost half were obese (43.4%, BMI ≥ 27.5 kg/m2). Participants without DR (vs mild DR) reported shorter DM duration, and had lower haemoglobin A1c, triglycerides and urine albumin/creatinine ratio (all p < 0.05). To date, we have extracted 41.8% (n = 1909) of the 12-month follow-up data. Of these, 99.7% (n = 1,904) did not progress to referable DR. Those who progressed to referable DR status (0.3%) had no DR at baseline.

CONCLUSIONS

In our prospective study of patients with T2DM and non-referable DR attending polyclinics, we found extremely low annual DR progression rates. These preliminary results suggest that extending screening intervals beyond 12 months may be viable and safe for most participants, although our 3-year follow up data are needed to substantiate this claim and develop the risk stratification model to identify low-risk patients with T2DM who can be assigned biennial or triennial screening intervals.

Efficiency, Precision, Validity, and Reliability of GlauCAT-Asian Computerized Adaptive Tests in Measuring Glaucoma-Related Quality of Life

Purpose

To determine the efficiency, precision, and agreement of GlauCAT-Asian and its corresponding validity and reliability.

Methods

In this cross-sectional study, 219 participants (mean ± standard deviation age, 66.59 ± 8.61 years; 34% female) across the spectrum of glaucoma severity and 50 glaucoma suspects were recruited from glaucoma clinics in Singapore. Participants answered seven computerized adaptive testing (CAT) evaluations (Ocular Comfort, Activity Limitation, Lighting, Mobility, Concerns, Psychosocial, Glaucoma Management) and underwent eye examinations. Efficiency (mean number of items required for each CAT and time taken for CAT versus full item banks [IBs]), agreement (concordance between CATs and full IB person measures, henceforth referred to as scores), and precision (standard error of measurement [SE]) were evaluated. Other validity and reliability metrics were also assessed.

Results

The mean number of items administered ranged from 9 (Mobility/Glaucoma Management) to 12 (Ocular Comfort). Compared to answering the full IBs, CATs provided an average time saving of 38.3% (range, 10% to 70.6% for Lighting and Activity Limitation, respectively). Agreement between scores obtained by CAT versus full IB was high (intracorrelation coefficient ≥0.75), as was precision of score estimates (mean SE range: 0.35 for Psychosocial to 0.29 for Mobility). Scores from Activity Limitation, Mobility, Lighting, and Concerns decreased significantly as glaucoma severity increased (criterion validity; P-trend <0.05). All tests displayed good convergent/divergent validity and test-retest reliability.

Conclusions

GlauCAT-Asian provides efficient, precise, accurate, valid, and reliable measurement of the patient-centered impact of glaucoma.

Translational Relevance

GlauCAT-Asian may provide a valuable clinical tool for ophthalmologists to monitor impact of disease progression and the effectiveness of therapies.

Individual and combined associations of sarcopenia, osteoporosis and obesity with frailty in a multi-ethnic asian older adult population

BACKGROUND

We explored the relationships between sarcopenia (SP), osteoporosis (OP), obesity (OB), (alone and in combination) with physical frailty (PF) in a multi-ethnic, population-based study of Asians aged ≥ 60 years.

METHODS

Participants were enrolled from the PopulatION HEalth and Eye Disease PRofile in Elderly Singaporeans Study (PIONEER) study. PF was defined using the modified Fried phenotype; SP using the Asian Working Group for Sarcopenia 2019; OP using bone mineral density scores; and OB using the fat mass index. Modified Poisson regression models investigated the associations between exposures and PF, and the relative excess rates of PF due to interactions (RERI) to determine synergistic or antagonistic interactions.

RESULTS

Of the 2643 participants, 54.8% was female; and 49.8%, 25.1%, 25.0% were Chinese, Indians, and Malays, respectively. 25%, 19.0% and 6.7% participants had OB only, SP only, and OP only, respectively. A total of 356 (17.5%), 151 (7.4%) and 97 (4.8%) had osteosarcopenia (OSP), sarcopenic obesity (SOB) and osteo-obesity (OOB), respectively; while 70 (3.5%) had all 3 morbid conditions (osteosarcopenic obesity, OSO). Both SP only and OB only were strongly associated with increased rates of PF (RR: 2.53, 95% CI: 1.95, 3.29; RR: 2.05, 95% CI: 1.58, 2.66 respectively); but not OP. Those with OSP, OOB and SOB were also associated with high risks of PF (RR: 2.82, 95% CI: 2.16, 3.68; RR: 2.34, 95% CI: 1.69, 3.23; and RR: 2.58, 95% CI: 1.95, 3.41, respectively) compared to robust individuals. Critically, individuals with OSO had the highest relative risk of having PF (RR: 3.06, CI: 2.28, 4.11). Only the sarcopenia-obesity interaction was significant, demonstrating negative synergism (antagonism). The concurrent presence of SP and OB was associated with a 100% lower rate of PF compared to the sum of the relatively rates of SP only and OB only.

CONCLUSION

The prevalence of SP, OB and OP, alone and combined, is substantial in older Asians and their early identification is needed to mitigate the risk of frailty. OB may interact with SP in an antagonistic manner to moderate rates of frailty. Further longitudinal studies are needed to address causality and mechanistic underpinnings our findings.

The economic burden of inherited retinal disease in Singapore: a prevalence-based cost-of-illness study

OBJECTIVE

To assess the economic impact of inherited retinal disease (IRD) among Singaporeans.

METHODS

IRD prevalence was calculated using population-based data. Focused surveys were conducted for sequentially enrolled IRD patients from a tertiary hospital. The IRD cohort was compared to the age- and gender-matched general population. Economic costs were expanded to the national IRD population to estimate productivity and healthcare costs.

RESULTS

National IRD caseload was 5202 cases (95% CI, 1734-11273). IRD patients (n = 95) had similar employment rates to the general population (67.4% vs. 70.7%; p = 0.479). Annual income was lower among IRD patients than the general population (SGD 19,500 vs. 27,161; p < 0.0001). Employed IRD patients had lower median income than the general population (SGD 39,000 vs. 52,650; p < 0.0001). Per capita cost of IRD was SGD 9382, with a national burden of SGD 48.8 million per year. Male gender (beta of SGD 6543, p = 0.003) and earlier onset (beta of SGD 150/year, p = 0.009) predicted productivity loss. Treatment of the most economically impacted 10% of IRD patients with an effective IRD therapy required initial treatment cost of less than SGD 250,000 (USD 188,000) for cost savings to be achieved within 20 years.

CONCLUSIONS

Employment rates among Singaporean IRD patients were the same as the general population, but patient income was significantly lower. Economic losses were driven in part by male patients with early age of onset. Direct healthcare costs contributed relatively little to the financial burden.

Synergistic Impact of Visual and Cognitive Impairments on Health-Related Quality of Life in a Multiethnic Asian Population

INTRODUCTION

The concomitant impact of visual impairment (VI) and cognitive impairment (CI) on health-related quality of life (HRQoL) in older adults is unclear. We aimed to determine the synergistic effect of baseline VI and CI on HRQoL decline at 6 years in multiethnic Asians.

METHODS

We included Chinese, Malay, and Indian adults aged ≥60 years who participated in baseline (2004-2011) and 6-year (2011-2017) follow-up visits of the Singapore Epidemiology of Eye Diseases Study, a population-based cohort study in Singapore. Visual acuity (VA) was objectively measured at both visits, with VI defined as presenting VA >0.3 LogMAR in the better eye. CI was defined as Abbreviated Mental Test scores of ≤6 and ≤8 for individuals with ≤6 and >6 years of formal education, respectively. HRQoL was measured using the European Quality of Life-5 Dimensions (EQ-5D) questionnaire. HRQoL decline was defined as the difference in the composite EQ-5D scores at baseline and 6-year follow-up and deemed clinically meaningful if the reduction was equal to or larger than the minimal clinically important difference. Multivariable linear regression assessed the independent associations and synergism (β interaction) between baseline VI and CI on EQ-5D decline.

RESULTS

Of the 2,433 participants (mean [SD] age: 67.6 [5.5]) at baseline, 559, 120, and 151 had VI only, CI only, and both impairments, respectively. HRQoL decline in individuals with baseline comorbid VI-CI was clinically meaningful and was 2.0 times (β = -0.044, 95% confidence interval: -0.077 to -0.010) and 3.7 times (β = -0.065, 95% confidence interval: -0.11 to -0.022) larger than those with VI only and CI only, respectively. Importantly, there was a significant synergism (β interaction = -0.048, 95% confidence interval: -0.095 to -0.001) between baseline VI and CI as predictors of HRQoL decline, suggesting that individuals having both conditions concurrently had a greater HRQoL reduction than the sum in those with VI alone and CI alone. The affected HRQoL domains included mobility and usual activities.

CONCLUSIONS

Concomitant VI-CI potentiated HRQoL decline to a greater extent than the sum of individual contributions of VI and CI, suggesting synergism. Our results suggest that rehabilitative interventions such as the use of mobility aids and occupational therapy are needed to maintain HRQoL in older adults with concomitant VI-CI. Moreover, preventive interventions targeting at early detection and management of both VI and CI may also be beneficial.

The Impact of Hearing Impairment on Health Indicators in a Multiethnic Population of Older Adults in Singapore

Background and Objectives

To determine the impact of hearing impairment (HI) on health indicators in a multiethnic Singaporean population of older adults.

Research Design and Methods

In this cross-sectional, population-based study, pure-tone averages of air-conduction thresholds at 500 Hz, 1,000 Hz, 2,000 Hz, and 4,000 Hz were calculated for each ear. Eight categories of HI were defined ranging from: 1: No HI to 8: Bilateral severe HI. Health indicators included hearing-related quality of life (H-QoL), depressive symptoms, frailty, gait speed, instrumental activities of daily living, sarcopenia, and cognitive impairment. Multivariable regression models determined the independent associations between HI and outcomes.

Results

A total of 2,503 older adults (mean age ± SD 73.4 ± 8.4; 55.2% female participants) were enrolled. Of these, 289 (11.6%), 259 (10.4%), 798 (31.9%), 303 (12.1%), 515 (20.6%), 52 (2.1%), 155 (6.2%), and 115 (4.6%) had hearing levels in Cats 1 to 8, respectively; and 20 (0.8%) used a hearing aid. Compared to those with no HI, participants with unilateral mild HI (Cat 2) had a 107% reduction in H-QoL (β: 0.63; CI: 0.18, 1.09, p = .006), increasing to a 2,816% reduction (β: 16.78; CI: 13.25, 20.31, p < .001) in those with bilateral severe HI-Cat 8 (p-trend < .001). Those with Cat 8 also had lower gait speed and we observed a nonsignificant increase in odds of frailty as HI worsened.

Discussion and Implications

H-QoL is affected across the spectrum of severity and laterality of HI. Interventions to alleviate the effects of HI and provision of QoL support are warranted. Other health indicators were only affected in late stages, suggesting that slowing disease progression is crucial in clinical management.

Measuring glaucoma quality of life in an Asian population using item banking: psychometric evaluation and computerized adaptive testing simulations

PURPOSE

To assess the psychometric properties of glaucoma-specific health-related quality of life (HRQoL) item banks (IBs), and explore their efficiency using computerized adaptive testing (CAT) simulations.

METHODS

In this cross-sectional, clinical study, 300 Asian glaucoma patients answered 221 items within seven IBs: Ocular Comfort Symptoms (OS); Activity Limitation (AL); Lighting (LT); Mobility (MB); Glaucoma Management (GM); Psychosocial (PSY); and Work (WK). Rasch analysis was conducted to assess each IB's psychometric properties (e.g., item "fit" to the construct; unidimensionality) and a set of analytic performance criteria guiding decision making relating to retaining or dropping domains and items was employed. CAT simulations determined the mean number of items for 'high' and 'moderate' measurement precision (stopping rule: SEM 0.3 and 0.387, respectively).

RESULTS

Participants' mean age was 67.2 ± 9.2 years (62% male; 87% Chinese). LT, MB, and GM displayed good psychometric properties overall. To optimize AL's psychometric properties, 16 items were deleted due to poor "fit", high missing data, item bias, low discrimination and/or a low clinical/patient importance rating. To resolve multidimensionality in PSY, we rehomed 16 items into a "Concern (CN)" domain. PSY and CN required further amendment, including collapsing of response categories, and removal of poorly functioning items (N = 7). Due to poor measurement precision, low applicability and high ceiling effect, low test information indices, and low item separation index the WK IB was not considered further. In CAT simulations on the final seven IBs (n = 182 items total), an average of 12.1 and 15.7 items per IB were required for moderate and high precision measurement, respectively.

CONCLUSIONS

After reengineering our seven IBs, they displayed robust psychometric properties and good efficiency in CAT simulations. Once finalized, GlauCAT™-Asian may enable comprehensive assessment of the HRQoL impact of glaucoma and associated treatments.

Three-year Outcomes of an Expanded Asynchronous Virtual Glaucoma Clinic in Singapore

PURPOSE

Virtual glaucoma clinics can help increase health care capacity, easing the disease burden of glaucoma. This study assesses the safety, rate of glaucoma progression, time efficiency, and cost-savings of our expanded Glaucoma Observation Clinic (GLOC) at the Singapore National Eye Centre over 3 years.

METHODS

All patients seen at GLOC between July 2018 and June 2021 were included. Visual acuity, intraocular pressure, and visual fields or optic nerve head imaging were recorded, followed by a virtual review of the data by an ophthalmologist. An objective review of the management of 100 patients was conducted by 2 senior consultants independently as a safety audit. Patient outcomes including the rate of instability (due to worsening of clinical parameters necessitating a conventional clinic visit), glaucoma progression, the consultation review time efficiency, and cost-savings of GLOC were measured.

RESULTS

Of 3458 patients, 16% had glaucoma, and the others had risk factors for glaucoma. The safety audit demonstrated a 95% interobserver agreement. The rate of instability was 14.6%, of which true progression was observed in 3.12%. The time taken for a glaucoma specialist to review a GLOC patient was 5.75±0.75 minutes compared with 13.7±2.3 minutes in a conventional clinic. The per capita manpower cost per GLOC patient per visit was $36.77 compared with $65.62 in the conventional clinic. This translates to a cost-saving of $280.65 over the lifetime of a hypothetical patient.

CONCLUSIONS

Our expanded virtual glaucoma clinic is a safe, time-efficient, and cost-effective model with low rates of glaucoma progression, which could allow for significant health care capacity expansion.

Hypertensive retinopathy and cardiovascular disease risk: 6 population-based cohorts meta-analysis

Background

The cardiovascular risk associated with different levels of hypertensive retinopathy, including mild, remains unclear. We performed an individual participant meta-analysis from 6 population-based cohort studies to determine the relationship of hypertensive retinopathy with incident cardiovascular outcomes.

Methods

We identified cohort studies that objectively assessed hypertensive retinopathy from photographs, documented incident cardiovascular outcomes, and were population-based. Six studies contributed data from 11,013 individuals at baseline with 5-13 years follow-up. Participants were recruited if they had hypertension and did not have confounding conditions such as diabetic retinopathy. Main outcome measures were incident coronary heart disease (CHD), stroke and a composite endpoint of cardiovascular disease (CHD or stroke). Pooled estimates of incident risk ratios (IRR) were obtained after adjusting for age, gender, systolic blood pressure, serum total cholesterol, high density lipoprotein and smoking.

Results

Among eligible participants with hypertension and without diabetes, there were 1018/9662 (10.5%) incident CHD events, 708/11,013 (6.4%) incident stroke events and 1317/9378 (14.0%) incident CVD events. Mild hypertensive retinopathy was associated with increased risk of CVD (IRR 1.13, 95% CI 1.00 to 1.27) and CHD (IRR 1.17, 95% CI 1.02 to 1.34) but not stroke; moderate hypertensive retinopathy was associated with increased risk of CVD (IRR 1.25 95% CI 1.02 to 1.53) but not stroke or CHD individually.

Conclusions

In persons with hypertension, both mild and moderate hypertensive retinopathy were associated with higher CVD risk.

Linguistic and Cultural Validation of the Diabetic Retinopathy Knowledge and Attitudes Scale (DRKA) in a Chinese Population

Purpose

To linguistically and culturally adapt the 31-item Singaporean Diabetic Retinopathy Knowledge and Attitudes (DRKA) questionnaire for a Chinese population and assess its reliability and validity using classical and modern psychometric theory.

Methods

A total of 230 patients with diabetic retinopathy (DR) were recruited, and of these, 202 valid responses were analyzed. Rasch analysis and classical test theory (CTT) methods were used to analyze the fit statistics of the Knowledge (n = 22 items) and Attitudes (n = 9 items) scales, including the functionality of the response categories, fit statistics, person and item reliability and separation, unidimensionality, targeting, differential item functioning (DIF), internal consistency, convergent validity, and known-group validity.

Results

After revision, both the Knowledge and Attitudes scales were unidimensional and had good measurement precision (Person Separation Index = 2.18 and 1.72) and internal consistency (Cronbach's α = 0.83 and 0.82). While the items in the Knowledge scale aptly targeted participants' ability level, targeting of the Attitudes scale was slightly suboptimal, with items too easy on average for participants' ability level. There were no issues with DIF and item fit, and the scales showed good known-group validity (scores increased as education level increased) and convergent validity (high correlation with the DRKA Practice questionnaire).

Conclusions

After a thorough language and cultural verification process, the Chinese version of the DRKA is culturally appropriate and has good psychometric performance.

Translational Relevance

The DRKA questionnaire may be useful to assess patients' DR-related knowledge and attitude level, as well as inform specific education interventions and optimize patients' ability to manage their condition.

Identifying Content for an Item Bank to Measure the Quality-of-Life Impact of Myopia Refractive Interventions

Purpose

To report on the content generation and item refinement phases for a myopia refractive intervention-specific quality-of-life (QoL) item bank that will be operationalized using computerized adaptive testing.

Methods

Myopia refractive intervention-specific QoL domains and items were generated from (1) a literature search of existing refractive-intervention QoL questionnaires; (2) semistructured interviews with myopic patients corrected using spectacles, contact lenses and/or refractive surgery (n = 32); (3) and myopia experts (n = 9) recruited from the Singapore National Eye Centre. After a thematic analysis, items were systematically refined and tested using cognitive interviews with 24 additional patients with corrected myopia.

Results

Of the 32 participants with myopia interviewed (mean ± standard deviation age, 35.6 ± 9.0 years; 71.9% female; 78.1% Chinese), 12 (37.5%) wore spectacles, 7 (21.9%) used contact lenses, and 20 (62.5%) had undergone laser refractive surgery. Initially, 912 items within 7 independent QoL domains were identified. After refinement, 204 items were retained, including those relating to mobility challenges and work-related difficulties that are not well-represented in current refractive intervention-specific questionnaires.

Conclusions

Through a rigorous item generation and selection process, we have developed a 204-item and 7-domain myopia refractive intervention-specific item bank that will now undergo rigorous psychometric testing to generate item calibrations for the validation of a novel computerized adaptive testing instrument designed for use in research and routine clinical practice.

Translational Relevance

Once psychometrically validated and operationalized using computerized adaptive testing, this myopia refractive intervention-specific instrument will enable researchers and clinicians to quickly and comprehensively assess the impact of myopic refractive interventions across seven QoL domains.

Oral Ibuprofen is Associated With Reduced Likelihood of Early Bleb Failure After Trabeculectomy in High-Risk Glaucoma Patients

PRCIS

Individuals prescribed ibuprofen after trabeculectomy have better postoperative intraocular pressure (IOP) control and a higher chance of bleb survival despite being at a higher risk of scarring.

PURPOSE

To investigate the effects of early adjunctive oral ibuprofen treatment on IOP and bleb failure in eyes at high risk of scarring.

METHODS

In these retrospective analyses, 288 eyes of 273 patients (mean ± SD age: 68.56 ± 10.47 y; 32.60% females) with primary glaucoma who underwent trabeculectomy/phacotrabeculectomy at the Singapore National Eye Centre between April 2020 and April 2021 with a follow-up duration ≥1 year were included. Of these, 77 (26.7%) eyes deemed to be at high risk of scarring were administered oral ibuprofen ≥3 months postoperatively (mean ± SD ibuprofen administration duration: 4.08 ± 2.28 wk). Participant's IOPs at baseline and at postoperative weeks 1, 2-3; and months 1, 2, 3, 6, and 12 were recorded. Bleb failure was defined as 2 consecutive IOP readings of >21, >18, and >15 mm Hg, and/or requiring remedial postoperative laser or surgery.

RESULTS

The ibuprofen group experienced significantly greater postoperative IOP reductions at week 1 [mean difference, 95%CI: -2.89 (-5.22, -0.56) mm Hg] and month 1 [-2.29 (-4.53, -0.05) mm Hg]; and substantially lower odds of bleb failure at the >18 mm Hg [odds ratio, 95% CI: 0.39 (0.20-0.79)] and >15 mm Hg [0.52 (0.29-0.94)] thresholds, compared with the non-ibuprofen group. No differences in adverse ocular hypotony events were observed.

CONCLUSION

Early adjunctive oral ibuprofen administered to individuals at high risk of posttrabeculectomy scarring is associated with greater IOP reductions and reduced likelihood of bleb failure. Our results suggest that oral nonsteroidal anti-inflammatory drugs may be a safe way of improving trabeculectomy survival in high-risk eyes.

Bilateral sequential small-incision lenticule extraction and LASIK result in similar short-term quality-of-life outcomes

PURPOSE

To compare quality of life (QoL) between patients who receive bilateral small-incision lenticule extraction (SMILE) or laser in situ keratomileusis (LASIK) vs bilateral sequential SMILE-LASIK (BSSL) surgery.

SETTING

Singapore National Eye Centre, Singapore.

DESIGN

Retrospective cohort study.

METHODS

2 patient cohorts were recruited (2010-2012; 2014-2016). The bilateral SMILE (BS) and bilateral LASIK (BL) groups comprised patients (mean ± SD age: 30.3 ± 6.5, 50% male) from a prospective nonrandomized study who chose SMILE and LASIK, respectively. The BSSL group comprised patients (mean ± SD age: 28.6 ± 6.2, 64.3% male) randomized to receive SMILE in 1 eye and LASIK in the other. Rasch-scaled scores of the QoL Impact of Refractive Correction questionnaire between groups postoperatively at 1 and 3 months were compared.

RESULTS

At month 1, scores on 3 QoL without emotional well-being items were worse in the BSSL (n = 70) compared with the BL group (n = 25), specficially, "using sunglasses" (β: -20.6, 95% CI, -34.3 to -6.9), "reliance on refractive correction" (-23.1, 95% CI, -40.9 to -5.4), and "medical complications from optical correction" (β: -14.8, 95% CI, -27.9 to -1.7). Emotional well-being (overall), and items "feeling able to do things" (β: 11.0, 95% CI, 1.6-20.4) and "feeling eager to try new things" (β: 14.1, 95% CI, 3.6-24.6) were better in the BSSL compared with the BS group (n = 25). No substantive differences were observed at month 3.

CONCLUSIONS

Refractive correction-related QoL differences at month 1 between BSSL and BS/BL patients attenuated by month 3. Bilateral sequential SMILE-LASIK surgery appeared unlikely to negatively affect QoL beyond 3 months.

The Patient Voice in Neovascular Age-Related Macular Degeneration: Findings from a Qualitative Study

INTRODUCTION

Visual impairment resulting from diseases such as neovascular age-related macular degeneration (nAMD) may cause behavioural, environmental, psychological, and logistical challenges that could act as barriers to effective uptake and sustainability of treatment with anti-vascular endothelial growth factor agents (anti-VEGFs). Understanding emotions and experiences of patients with nAMD may help inform the determinants of adherence, and could contribute to improvements in ophthalmic outcomes and quality of life.

METHODS

Seventeen patients with nAMD receiving anti-VEGF injections were enrolled from three clinics: one each in France (n = 5), Germany (n = 6), and the UK (n = 6). Patients' health information and treatment characteristics were collected. Individual phone interviews were conducted by experienced health care interviewers. Transcripts were analysed thematically.

RESULTS

Patients (53% female) had a mean age of 77 years. Bilateral anti-VEGF injections were received by 24% (n = 4); and most (76%, n = 13) were adherent to their treatment. Patient emotions at diagnosis ranged from happiness at learning about the treatment for nAMD to being terrified of receiving an injection in the eye. Most patients mentioned feeling anxious and fearful before their first injection despite receiving reassurance. After the first injection, these feelings and apprehension abated for many, but not all. With the goal of maintaining the best possible vision, few (24%, n = 4) patients reported more than one missed appointment, and most had never considered stopping treatment. No patient reported additional assistance beyond family support; however, many had difficulties with recreational and domestic activities and had developed coping strategies.

CONCLUSION

This study provides insights on patients' emotions related to their experience of nAMD and its management, highlighting the varying experiences between individuals. It shows the importance of the patient's voice when considering patient care and management, and how the nature and timing of interventions can improve the experience of living with and managing nAMD.

The development of a glaucoma-specific health-related quality of life item bank supporting a novel computerized adaptive testing system in Asia

Background

A glaucoma-specific health-related quality of life (HRQoL) item bank (IB) and computerized adaptive testing (CAT) system relevant to Asian populations is not currently available. We aimed to develop content for an IB focusing on HRQoL domains important to Asian people with glaucoma; and to compare the content coverage of our new instrument with established glaucoma-specific instruments.

Methods

In this qualitative study of glaucoma patients recruited from the Singapore National Eye Centre (November 2018-November 2019), items/domains were generated from: (1) glaucoma-specific questionnaires; (2) published articles; (3) focus groups/semi-structured interviews with glaucoma patients (n = 27); and (4) feedback from glaucoma experts. Data were analyzed using the constant comparative method. Items were systematically refined to a concise set, and pre-tested using cognitive interviews with 27 additional glaucoma patients.

Results

Of the 54 patients (mean ± standard deviation [SD] age 66.9 ± 9.8; 53.7% male), 67 (62.0%), 30 (27.8%), and 11 (10.2%) eyes had primary open angle glaucoma, angle closure glaucoma, and no glaucoma respectively. Eighteen (33.3%), 11 (20.4%), 8 (14.8%), 12 (22.2%), and 5 (9.3%) patients had no, mild, moderate, severe, or advanced/end-stage glaucoma (better eye), respectively. Initially, 311 items within nine HRQoL domains were identified: Visual Symptoms, Ocular Comfort Symptoms, Activity Limitation, Driving, Lighting, Mobility, Psychosocial, Glaucoma management, and Work; however, Driving and Visual Symptoms were subsequently removed during the refinement process. During cognitive interviews, 12, 23 and 10 items were added, dropped and modified, respectively.

Conclusion

Following a rigorous process, we developed a 221-item, 7-domain Asian glaucoma-specific IB. Once operationalised using CAT, this new instrument will enable precise, rapid, and comprehensive assessment of the HRQoL impact of glaucoma and associated treatment efficacy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41687-022-00513-3.

Psychometric Evaluation of Glaucoma Quality of Life Item Banks (GlauCAT) and Initial Assessment Using Computerized Adaptive Testing

Purpose

To evaluate the psychometric properties of glaucoma-specific quality of life (QoL) item banks (GlauCAT) and assess their performance using computerized adaptive testing (CAT) simulations.

Methods

In this cross-sectional study, 293 participants with glaucoma (mean age ± SD, 70.7 ± 13.2 years; 45% female) answered 342 items in 12 QoL item banks (IBs): Activity Limitation (AL); Driving (DV); Convenience (CV); Economic (EC); Emotional (EM); General Symptoms (GS); Health Concerns (HC); Lighting (LT); Mobility (MB); Ocular Surface Symptoms (OS); Social (SC); and Visual Symptoms (VS). These IBs were assessed using Rasch analysis, and CAT simulations with 1000 simulated respondents were utilized to determine the average number of items to be administered to achieve moderate and high precision levels.

Results

The AL, DV, EM, HC, LT, MB, EC, OS, SC, and VS IBs required relatively minor amendments to achieve satisfactory psychometric fit. To resolve multidimensionality, we split CV into Treatment Convenience (TCV) and General Convenience (GCV). Due to poor measurement precision, the GS IB was not pursued further. This resulted in 12 total IBs. In CAT simulations, an average of 3.7 and 7.3 items per IB were required to attain measurement at moderate and high precision, respectively.

Conclusions

Following rigorous psychometric assessment, we developed 12 valid glaucoma-specific QoL domains that can obtain highly precise person measure estimates using a small number of items.

Translational Relevance

GlauCAT will enable researchers and clinicians to quickly and comprehensively assess the impact of glaucoma and its associated interventions across a range of QoL domains.

The longitudinal association between cognitive impairment and incident visual impairment in a multiethnic Asian population: a prospective cohort study

BACKGROUND

The relationship between baseline cognitive impairment (CI) and incident visual impairment (VI) in Asians is unclear.

OBJECTIVE

To determine the associations between baseline CI with incident VI and visual acuity (VA) at 6-year follow-up in multiethnic Asians.

DESIGN

Cohort.

SETTING

Population-based.

SUBJECTS

Two thousand three hundred and twenty-four adults aged ≥60 years from the Singapore Epidemiology of Eye Diseases Study (response rate 64%).

METHODS

CI was defined using the validated Abbreviated Mental Test (AMT). VA was objectively measured using a LogMAR chart. Any incident VI was defined as having no VI (Snellen's VA better than or equal to 20/40) at baseline but present (VA worse than 20/40) at 6-year follow-up. VI severity was defined according to the International Classification of Diseases, 11th Revision. Associations were assessed using logistic and linear regression models.

RESULTS

Of the 2,324 participants, 248 had CI at baseline. Presence of baseline CI was associated with more than twice the odds of any incident VI, incident mild and moderate-severe VI (OR [95% confidence interval]: 2.48 [1.55-3.90], 2.07 [1.17-3.55], and 2.61 [1.36-4.93], respectively) and worse VA (β [95% confidence interval]: 0.026 [0.006-0.046]) at 6-year follow-up. The leading causes of incident VI were cataract and under-corrected refractive error.

CONCLUSIONS

Older adults with CI had more than double the odds of VI development and poorer VA than their cognitively intact counterparts, and most causes of incident VI were correctable. Strategies such as targeted vision screening and early intervention for early detection and management of vision loss in patients with cognitive decline are warranted.

Association between age-related sensory impairment with sarcopenia and its related components in older adults: a systematic review

Sensory impairments and sarcopenia are both highly prevalent age-related conditions, with the former having been postulated to contribute to the pathogenesis of the latter condition. Confirming this hypothesis may therefore help to better inform strategies for early treatment and intervention of sarcopenia. We performed a systematic review of the current literature examining the relationships between four major sensory impairments [vision (VI), hearing (HI), smell (SI), and taste (TI)] with (i) sarcopenia; and (ii) its associated components (low handgrip strength, slow gait speed, and low muscle mass). PubMed, EMBASE, CINAHL, and Cochrane Library databases were searched for observational studies investigating the relationship of VI, HI, SI, and TI with sarcopenia, low handgrip strength, slow gait speed, and low muscle mass, in adults aged 50 years or older, from inception until 24 May 2021. The risk of bias of the included studies was assessed using the Newcastle-Ottawa Scale. This study was registered with PROSPERO, reference CRD42021247967. Ten cross-sectional and three longitudinal population-based studies of community-dwelling adults (N = 68 235) were included, with five studies investigating more than one sensory impairment. In total, 8, 6, 3, and 1 studies investigated the relationship between VI, HI, SI, and TI and sarcopenia and its related components, respectively. Follow-up duration for the longitudinal studies ranged from 4 to 11 years. All studies had a low or moderate risk of bias. We found that the presence of VI and SI, but not TI, independently increased the odds of sarcopenia. In addition, VI and SI were each independently associated with low muscle mass; and VI, HI, and SI were each independently associated with slow gait speed. However, we found inconclusive evidence for the associations between VI, HI and SI, and low handgrip strength. Our systematic review suggests a potential association between the presence of single or multiple sensory impairments and a greater likelihood of sarcopenia and/or deficits in its associated components, especially for VI, HI, and SI. Prospective studies are needed to untangle the relationship between sensory impairment and sarcopenia to better inform clinical guidelines for disease prevention and management.

Impact of Acanthamoeba Keratitis on the Vision-Related Quality of Life of Contact Lens Wearers

PURPOSE

The aim of this study was to determine the impact of Acanthamoeba keratitis (AK) caused by contact lens (CL) use on vision-related quality of life (VRQOL) and the sociodemographic factors and disease outcome associated with VRQOL.

METHODS

Sixty-one CL-associated AK cases and 59 asymptomatic CL wearers (mean age ±SD 39.4 ± 16.5 vs. 45.5 ± 15.2 yrs, P = 0.04) were recruited from Moorfields Eye Hospital and Institute for Optometry, London. AK cases were surveyed during active disease and were stratified into "poor" and "good" outcomes based on clinical features. VRQOL was measured using Rasch-transformed scores from the Emotional, Mobility, and Reading domains of the 32-item Impact of Visual Impairment questionnaire. AK cases were compared with controls and "poor" outcomes compared with "good" with multivariable linear regression. Multivariable linear regression models were also used to identify the sociodemographic factors and disease outcome associated with VRQOL.

RESULTS

AK was associated with significant and substantial reductions in all 3 evaluated domains of VRQOL (Reading -59.6%, Mobility -59.8%, and Emotional -66.2%) compared with controls, independent of sociodemographic factors. Patients with AK who experienced poor outcomes, those who were of British White race (compared with all other races) and female, had lower VRQOL scores across all domains. Patients with AK with lower incomes scored worse on Reading and Mobility domains, whereas those with lower education had poorer Emotional scores.

CONCLUSIONS

AK has a considerable detrimental impact on VRQOL. Clinicians should consider the importance of referring patients with AK for rehabilitative support and counseling as part of active disease management.

Implementation of an Online Glaucoma-Specific Quality of Life Computerized Adaptive Test System in a US Glaucoma Hospital

Purpose

The feasibility of implementing a computerized adaptive test (CAT) system in routine clinical care in ophthalmology has not been assessed. We evaluated the implementation of a glaucoma-specific CAT (GlauCAT) in outpatients at Massachusetts Eye and Ear Institute.

Methods

In this implementation study (July 2020–April 2021), 216 adults (mean ± SD age 64.8 ± 15.3 years; 56.0% women) completed six adaptive GlauCAT quality of life (QOL) tests on an internet-enabled tablet at the clinic. A real-time printable report summarizing domain scores was shared with physicians prior to consultation. The implementation was evaluated using Proctor's outcomes: acceptability (patient satisfaction); appropriateness (independent complete rate [%]); feasibility (acceptance rate [%]; completion time); and fidelity (percentage of patients discussing GlauCAT results with their physician). Physician barriers/facilitators were explored using open-ended questions.

Results

Patients’ mean ± SD satisfaction score was 3.5 ± 0.5 of 4, with >95% of patients willing to recommend it to others. Of the 216 (89.2%) patients accepting to participate, 173 (80%) completed GlauCAT independently. Patients took 8 minutes and 5 seconds (median) to complete all 6 GlauCAT tests. Almost two-thirds (n = 136/216) of the patients reported discussing their GlauCAT results with their doctor. Physicians described the GlauCAT summary report as helpful and user-friendly, although lack of time and uncertainty about how to action information were reported.

Conclusions

Pilot implementation of six GlauCAT QOL tests in glaucoma outpatient clinics was feasible and acceptable. Integration of GlauCAT with electronic medical records (EMRs) and evaluation of long-term implementation outcomes are needed.

Translational Relevance

GlauCAT's multiple outcomes and low test-taking burden makes it attractive for measuring glaucoma-specific QOL in routine clinical care.

The longitudinal psychological, physical activity, and financial impact of a COVID-19 lockdown on older adults in Singapore: The PIONEER-COVID population-based study

BACKGROUND

Several countries have implemented 'lockdown' measures to curb the spread of the coronavirus disease 2019 (COVID-19).

AIMS

To examine the psychological, physical activity (PA), and financial impact of a 2-month COVID-19 lockdown on older adults aged ≥60 years in Singapore, and to identify factors associated with adverse lockdown-related outcomes.

METHOD

We interviewed 496 community-dwelling adults (mean age [standard deviation]: 73.8 [7.6] years; 54.8% female) during the lockdown who had previously participated in a population-based epidemiological study. Validated questionnaires were utilised to assess loneliness and depressive symptoms at both timepoints, while inhouse questionnaires were used to assess PA and financial difficulty during lockdown. Multivariable regression models determined the lockdown-related change in loneliness and depression scores, and the factors associated with adverse outcomes.

RESULTS

Loneliness increased significantly during the lockdown period (p < 0.001) while depressive symptoms decreased (p = 0.022). Decreased PA, greater financial problems, male gender, Indian ethnicity, living alone, having a greater body mass index and perceived susceptibility to COVID-19 were all associated with worsening loneliness scores. A total of 36.9% and 19.6% participants reported decreased PA and had financial problems during the lockdown, respectively. Unemployment was associated with decreased PA, while self-employed individuals, cleaners, retail workers and smokers had greater odds of experiencing financial difficulty.

CONCLUSION

Despite a decrease in depressive symptoms, our population of older Asians reported a significant increase in loneliness and decreased PA, with one-fifth experiencing financial problems during lockdown. Our data suggest that more targeted public health efforts are needed to reduce repercussions of future lockdowns.

Identifying the content for an item bank and computerized adaptive testing system to measure the impact of age-related macular degeneration on health-related quality of life

PURPOSE

We are developing an age-related macular degeneration (AMD) health-related quality of life (HRQoL) item bank, applicable to Western and Asian populations. We report primarily on content generation and refinement, but also compare the HRQoL issues reported in our study with Western studies and current AMD-HRQoL questionnaires.

METHODS

In this cross-sectional, qualitative study of AMD patients attending the Singapore National Eye Centre (May-December 2019), items/domains were generated from: (1) AMD-specific questionnaires; (2) published articles; (3) focus groups/semi-structured interviews with AMD patients (n = 27); and (4) written feedback from retinal experts. Following thematic analysis, items were systematically refined to a minimally representative set and pre-tested using cognitive interviews with 16 AMD patients.

RESULTS

Of the 27 patients (mean ± standard deviation age 67.9 ± 7.0; 59.2% male), 18 (66.7%), two (7.4%), and seven (25.9%) had no, early-intermediate, and late/advanced AMD (better eye), respectively. Whilst some HRQoL issues, e.g. activity limitation, mobility, lighting, and concerns were similarly reported by Western patients and covered by other questionnaires, others like anxiety about intravitreal injections, work tasks, and financial dependency were novel. Overall, 462 items within seven independent HRQoL domains were identified: Activity limitation, Lighting, Mobility, Emotional, Concerns, AMD management, and Work. Following item refinement, items were reduced to 219, with 31 items undergoing amendment.

CONCLUSION

Our 7-domain, 219-item AMD-specific HRQoL instrument will undergo psychometric testing and calibration for computerized adaptive testing. The future instrument will enable users to precisely, rapidly, and comprehensively quantify the HRQoL impact of AMD and associated treatments, with item coverage relevant across several populations.

Development and Validation of a Preference-Based Glaucoma Utility Instrument Using Discrete Choice Experiment

Importance

A glaucoma-specific instrument for estimating utilities across the spectrum of glaucoma severity is currently lacking, hindering the assessment of the cost-effectiveness of glaucoma treatments.

Objective

To develop and validate the preference-based Glaucoma Utility Instrument (Glau-U) and to ascertain the association between Glau-U utilities and severity of glaucoma and vision impairment.

Design, Setting, and Participants

This cross-sectional study was conducted in 2 stages at the Singapore National Eye Centre glaucoma clinics. Stage 1 focused on the identification and pretesting of the Glau-U attributes and was carried out between June 2009 and May 2016. Stage 2 involved the development and administration of the discrete choice experiment (DCE) survey and tasks and was conducted between May 7, 2018, and December 11, 2019. Stage 2 participants were English- or Mandarin-speaking Singaporean citizens or permanent residents of Chinese, Malay, or Indian ethnicity who were 40 years or older and had a clinical diagnosis of glaucoma in at least 1 eye.

Exposures

Glau-U comprised 6 quality-of-life attributes: activities of daily living, lighting and glare, movement, eye discomfort, other effects of glaucoma, and social and emotional effects. The descriptions or response options for these attributes were no difficulty or never, some difficulty or sometimes, or severe difficulty or often.

Main Outcomes and Measures

Utility weights for Glau-U were developed using a DCE questionnaire, which was interviewer administered to participants. Mixed logit regression determined utility weights for each health state. Glau-U utility weights across better- or worse-eye glaucoma and vision impairment severity were calculated using 1-way analysis of variance. Correlations between Glau-U utilities and better- or worse-eye visual fields and EuroQol 5-Dimension utilities were ascertained to assess convergent and divergent validity.

Results

Of the 304 participants (mean [SD] age, 68.3 [8.7] years; 182 men [59.9%]), 281 (92.4%) had no vision impairment in the better eye, 13 (4.3%) had mild impairment, and 10 (3.3%) had moderate to severe vision impairment. Mean (SD) Glau-U utilities decreased as better-eye glaucoma severity increased (none: 0.73 [0.21]; mild: 0.66 [0.21]; moderate: 0.66 [0.20]; severe: 0.60 [0.28]; and advanced or end-stage: 0.22 [0.38]; P < .001), representing reductions of 20.7% to 76.1% in quality-adjusted life-years compared with a health state that included preperimetric glaucoma. Mean (SD) Glau-U utilities also decreased as better-eye vision impairment worsened from 0.67 (0.23) for none to 0.58 (0.32) for mild to 0.46 (0.29) for moderate to severe vision impairment. Glau-U utilities demonstrated moderate correlations with better-eye (r = 0.34; P < .001) and worse-eye (r = 0.33; P < .001) mean deviation scores and low correlations with EuroQol 5-Dimension utilities (r = 0.22; P < .001), supporting convergent and divergent validity.

Conclusions and Relevance

Use of Glau-U revealed large decrements in utility that were associated with late-stage glaucoma, suggesting that this new instrument may be useful for cost-effectiveness analyses of interventions and informing resource allocation policies for glaucoma and vision loss.

Vision, vision-specific functioning and mobility, and their relationship with clinically assessed cognitive impairment

BACKGROUND

The relationship between self-reported visual disability and cognitive impairment in older individuals is unclear.

OBJECTIVE

To determine the relationship of vision-specific functioning (VSF), vision-specific mobility (VSM) and visual acuity (VA) with clinically assessed cognitive impairment in the Epidemiology of Dementia in Singapore study.

DESIGN

Cross-sectional.

SETTING

Population-based.

SUBJECTS

Eight hundred and seventy-four adults aged ≥60 years at higher risk of possible cognitive impairment by the Abbreviated Mental Test and progressive forgetfulness question.

METHODS

VSF and VSM were measured using Rasch-transformed continuous scores of two Impact of Vision Impairment questionnaire domains. Cognitive impairment was objectively determined using detailed neuropsychological testing and defined as no cognitive impairment (NCI), mild cognitive impairment-no dementia (CIND), moderate CIND only and moderate CIND or dementia. Associations were assessed using multinomial logistic regression models.

RESULTS

Of the 874 participants (49.0% males, mean age (SD) 65.5 (7.0) years), 277, 281 and 316 had NCI, mild CIND and moderate CIND or dementia, respectively. Compared to NCI, the odds of moderate CIND, and moderate CIND or dementia increased for every SD worsening in VSF (OR: 1.44, 95% CI 1.14-1.82, and OR: 1.52, 95%CI 1.19-1.94, respectively) and VSM (OR: 1.42, 95%CI 1.11-1.81, and OR: 1.50, 95%CI 1.15-1.95). Similarly, the odds of mild CIND (OR: 1.62, 95%CI 1.19-2.22), moderate CIND (OR: 1.93, 95%CI 1.45-2.58), and moderate CIND or dementia (OR: 2.25, 95%CI 1.62-3.11) increased significantly with every SD worsening of VA.

CONCLUSIONS

Our results emphasise the importance of interventions to prevent vision loss and improve quality of life to reduce likelihood of age-related cognitive decline.

Prevalence, Associated Factors and Health-related Quality of Life of Dual Sensory Impairment in Residential Care Facilities in Singapore

Purpose: To investigate the prevalence of dual sensory impairment (DSI), its associated factors and relationship with health-related quality of life (HR-QoL) in residential care facilities (RCF) in Singapore.Methods: This was a cross-sectional study of 123 residents aged ≥40 years from six RCFs, conducted between 2016 and 2018. DSI was defined as concomitant presenting visual acuity (better-eye) >0.3 logarithm of the minimum angle of resolution and a pure-tone air conduction threshold (better-ear) >40 dB HL in any of the four tested frequencies (500, 1000, 2000 and 4000 Hz). HR-QoL was quantified using the EuroQol five-dimension questionnaire. Multivariable Poisson regression was used to determine the associated factors of DSI. Multivariable linear regression was used to determine the association between DSI and HR-QoL adjusted for traditional confounders.Results: Of the 123 residents (age [mean±standard deviation] 75.3 ± 10.8 years; 56.9% male), 97 (78.9%[95% confidence interval(CI):71.6%, 86.1%]) had DSI, with 110 (98.2%) not on follow-up care for their sensory disabilities. In multivariable models, male gender (prevalence ratio(PR) [95%CI] = 1.3[1.1, 1.6]), older age (per 10-year increase (1.2[1.1, 1.3])), education ≤6 years (1.3[1.1, 1.7]) and the presence of cataract (1.3[1.0, 1.7]) were independently associated with DSI. DSI was independently associated with a substantial worsening in HR-QoL (β = -0.61; 95%CI: -0.76, -0.45; p < .001).Conclusions: DSI affects four in five residential care residents and is substantially associated with reductions in HR-QoL in these residents. Our finding highlights an urgent need for the implementation of routine vision and hearing screening and follow-up care for residents living in these facilities.

Outcomes of an Asynchronous Virtual Glaucoma Clinic in Monitoring Patients at Low Risk of Glaucoma Progression in Singapore

PURPOSE

To assess the implementation outcomes of a new asynchronous virtual clinic, the Glaucoma Observation Clinic (GLOC), at the Singapore National Eye Center, in monitoring patients at low risk for glaucoma progression.

METHODS

Patients with low risk of glaucoma progression were followed up at GLOC. Visual acuity, intraocular pressure, and visual field testing or optic nerve head imaging were assessed by nurses and technicians, with virtual review of data by an ophthalmologist separately. The implementation outcomes were defined as patient satisfaction, assessed by a nurse-administered questionnaire; the rate of referrals back to the glaucoma outpatient department; the patients' journey time (minutes); the time taken for the specialist review (minutes), and the per capita manpower cost compared with current glaucoma outpatient model.

RESULTS

A total of 377 patients were included, with the majority being glaucoma disc suspects (n = 250, 66.4%) and primary angle closure suspects (n = 54, 14.3%). Most patients (more than 90%) reported being satisfied, and only 7.7% (n = 29) were referred back to the specialist outpatient glaucoma clinic due to possible glaucoma progression. Compared with the glaucoma outpatient clinic, the average journey time in GLOC was 50% less (59.3 mins vs 132 mins), the average time for a specialist review was 3 times faster (5.8 mins vs 19.5 mins), and the per capita manpower cost of GLOC was halved ($20.07 vs $39.78).

CONCLUSIONS

GLOC is a time-efficient, cost-saving, and sustainable model of care for managing patients with low risk of glaucoma progression. It was well received by patients and freed up the conventional clinic to treat patients with complex needs.

The Bidirectional Relationship between Vision and Cognition: A Systematic Review and Meta-analysis

TOPIC

Visual impairment (VI) and cognitive impairment (CIM) are prevalent age-related conditions that impose substantial burden on the society. Findings on the hypothesized bidirectional association of VI and CIM remains equivocal. Hence, we conducted a systematic review and meta-analysis to examine this bidirectional relationship.

CLINICAL RELEVANCE

Sixty percent risk of CIM has not been well elucidated in the literature. A bidirectional relationship between VI and CIM may support the development of strategies for early detection and management of risk factors for both conditions in older people.

METHODS

PubMed, Embase, and Cochrane Central registers were searched systematically for observational studies, published from inception until April 6, 2020, in adults 40 years of age or older reporting objectively measured VI and CIM assessment using clinically validated cognitive screening tests or diagnostic evaluation. Meta-analyses on cross-sectional and longitudinal associations between VI and CIM outcomes (any CIM assessed using screening tests and clinically diagnosed dementia) were examined. Random effect models were used to generate pooled odds ratios (ORs) and 95% confidence intervals (CIs). We also examined study quality, publication bias, and heterogeneity.

RESULTS

Forty studies were included (n = 47 913 570). Meta-analyses confirmed that persons with VI were more likely to have CIM, with significantly higher odds of: (1) any CIM (cross-sectional: OR, 2.38 [95% CI, 1.84-3.07]; longitudinal: OR, 1.66 [95% CI, 1.46-1.89]) and (2) clinically diagnosed dementia (cross-sectional: OR, 2.43 [95% CI, 1.48-4.01]; longitudinal: OR, 2.09 [95% CI, 1.37-3.21]) compared with persons without VI. Significant heterogeneity was explained partially by differences in age, sex, and follow-up duration. Also, some evidence suggested that individuals with CIM, relative to cognitively intact persons, were more likely to have VI, with most articles (8/9 [89%]) reporting significantly positive associations; however, meta-analyses on this association could not be conducted because of insufficient data.

DISCUSSION

Overall, our work suggests that VI is a risk factor of CIM, although further work is needed to confirm the association of CIM as a risk factor for VI. Strategies for early detection and management of both conditions in older people may minimize individual clinical and public health consequences.

Rationale and Methodology of The PopulatION HEalth and Eye Disease PRofile in Elderly Singaporeans Study [PIONEER]

To describe the rationale, design and methodology of a geographically-representative and population-based study investigating the epidemiology, impact, personal and economic burden of age-related eye diseases, declining visual and other sensory systems in Asians aged >60 years in Singapore.PIONEER (The PopulatION HEalth and Eye Disease PRofilE in Elderly Singaporeans Study) is currently a cross-sectional study targeting 3152 Chinese, Malay and Indian adults who are Singapore citizens or permanent residents aged 60 years and older living across Singapore. The study is intended to be longitudinal, with several waves of data planned to be collected in the future. The sampling frame consisted of 7000 names derived from age, gender and ethnicity-stratified random sampling of individuals >60 years. Selected individuals were invited via letters, home visits, and telephone calls for a clinical assessment at the Singapore Eye Research Institute. Individuals with limited mobility were examined in a custom-designed mobile eye clinic. Questionnaires were subsequently administered at participants' homes by trained interviewers in their preferred language. A total of 3,299 participants (from East, West, North and South Singapore) were approached from December 2017 to November 2019. Of these, 953 (28.5%) were deemed ineligible. Out of 2,346 eligible participants, 904 (38.5%) refused, and 1,442 (61.5%) attended our clinical testing protocol, giving an initial response rate of 61.5%. Of these, 1,170 (81%) were cognitively able to complete the questionnaire assessment. The mean age±SD of our participants was 73.8±8.6 years; n=798 (55.3%) were female; and 828 (57.4%) were of Chinese ethnicity. The findings from this study will allow a deeper understanding of the risk factors and impact of aging in Asian populations, particularly in relation to the visual function and other functional system.

Validation of a New Diabetic Retinopathy Knowledge and Attitudes Questionnaire in People with Diabetic Retinopathy and Diabetic Macular Edema

Purpose

A validated questionnaire assessing diabetic retinopathy (DR)- and diabetic macular edema (DME)-related knowledge (K) and attitudes (A) is lacking. We developed and validated the Diabetic Retinopathy Knowledge and Attitudes (DRKA) questionnaire and explored the association between K and A and the self-reported difficulty accessing DR-related information (hereafter referred to as Access).

Methods

In this mixed-methods study, eight focus groups with 36 people with DR or DME (mean age, 60.1 ± 8.0 years; 53% male) were conducted to develop content (phase 1). In phase 2, we conducted 10 cognitive interviews to refine item phrasing. In phase 3, we administered 28-item K and nine-item A pilot questionnaires to 200 purposively recruited DR/DME patients (mean age, 59.0 ± 10.6 years; 59% male). The psychometric properties of DRKA were assessed using Rasch and classical methods. The association between K and A and DR-related Access was assessed using univariable linear regression of mean K/A scores against Access.

Results

Following Rasch-guided amendments, the final 22-item K and nine-item A scales demonstrated adequate psychometric properties, although precision remained borderline. The scales displayed excellent discriminant validity, with K/A scores increasing as education level increased. Compared to those with low scores, those with high K/A scores were more likely to report better access to DR-related information, with K scores of 0.99 ± 0.86 for no difficulty; 0.79 ± 1.05 for a little difficulty; and 0.24 ± 0.85 for moderate or worse difficulty (P < 0.001).

Conclusions

The psychometrically robust 31-item DRKA questionnaire can measure DR- and DME-related knowledge and attitudes.

Translational Relevance

The DRKA questionnaire may be useful for interventions to improve DR-related knowledge and attitudes and, in turn, optimize health behaviors and health literacy.

Rates and Predictors of Nonadherence to Postophthalmic Screening Tertiary Referrals in Patients with Type 2 Diabetes

Purpose

To determine the rates and develop an initial risk prediction model for nonadherence to post screening ophthalmic referral (PSOR) in type 2 diabetes mellitus (T2DM) patients attending a national diabetic retinopathy screening program in Singapore.

Methods

Data from 2387 patients with T2DM (mean [standard deviation] age: 66.5 [11] years; 52.5% female patients) who underwent teleophthalmic screening between 2010 and 2014 under the Singapore Integrated Diabetic Retinopathy Program were extracted from electronic medical records. All were referred for tertiary ophthalmic management at the Singapore National Eye Centre (SNEC). Nonadherence was defined as not attending the SNEC appointment within 6 months of the assigned appointment date. Regression analysis using traditional modified Poisson and conditional inference models was used to construct and evaluate the discriminative ability of the preliminary risk prediction model to identify nonadherent individuals.

Results

Nonadherence rates to PSOR was 12.7% (95% confidence interval, 11.4%–14.1%). In traditional multivariable models adjusted for sociodemographic, lifestyle, and ocular factors, nonadherent individuals had higher triglyceride levels and were less likely to have a referable eye condition (P < 0.05). This model was able to identify nonadherent individuals with an accuracy (area under the curve) of 84%. In contrast, the conditional inference model was able to achieve similar discriminative ability using only participants’ ocular health characteristics.

Conclusions

The rates of nonadherence to PSOR in Singaporean individuals with T2DM is low, with better ocular health being strongly predictive of nonadherence in our Asian population.

Translational Relevance

Our results may inform interventions to decrease nonadherence to PSOR.

Rates and Determinants of Eyecare Utilization and Eyeglass Affordability Among Individuals With Visual Impairment in a Multi-Ethnic Population-Based Study in Singapore

Purpose

The purpose of this study was to determine the rates of, and factors associated with, eyecare utilization and spectacle affordability among Singaporeans with vision impairment (VI).

Methods

We included adults with VI from their second visit of the Singapore Epidemiology of Eye Disease Study. Data on eyecare utilization and spectacle affordability were collected. Low eyecare utilization was defined as no eye check ever or eye checks not even once per year in reference to at least once per year. Difficulty affording glasses was defined as glasses being rated as expensive in reference to not expensive.

Results

There were 985 adults (14.5%; 415 Malays, 260 Indian, and 310 Chinese; mean age [SD]: 69.5 [10.2] years; 55.4% women) with VI who answered the above questions, were included. Of these, 624 (63.4%) wore glasses. The rates of low eyecare utilization and difficulty affording eyeglasses were 31% and 63%, respectively. Compared to Chinese (23.8%) and Indians (18.8%), Malays (57.4%) had the highest rates of low eyecare utilization (P < 0.001), and most difficulty affording eyeglasses (47.2% vs. 26.1% and 26.6% in Chinese and Indians, respectively; P < 0.001). Younger age, low socioeconomic status, absence of diabetes, absence of self-reported eye conditions, and poor vision were independently associated with low eyecare utilization, whereas older age and female sex was associated with difficulty affording glasses.

Conclusions

In this multi-ethnic population with VI, almost one-third had low eyecare utilization and nearly two-thirds reported difficulty affording eyeglasses.

Translational Relevance

This will inform strategies, such as tailored eyecare utilization awareness campaigns and awareness of available subsidy schemes for at-risk Singaporeans, such as Malays.

The Differential Impact of Age on Vision-Related Quality of Life across the Visual Impairment Spectrum

PURPOSE

Visual impairment (VI) can have a detrimental impact on vision-related quality of life (VRQoL), but it is still unclear how this relationship varies with age across the VI spectrum. We determined the age-stratified, cross-sectional, and longitudinal associations between VI severity and VRQoL.

DESIGN

The baseline and follow-up Singapore Chinese Eye Studies (SCES-1/-2; 2009-2011 and 2015-2017).

PARTICIPANTS

A total of 3068 SCES-1 participants (mean age [standard deviation {SD}]: 59.5 [9.8] years; 50.2% female) and 1919 SCES-2 participants (mean age [SD]: 56.8 [8.3] years; 49.9% female).

METHODS

Visual impairment was defined as visual acuity (VA) of > 0.3 logarithm of the minimum angle of resolution (logMAR) units; VI severity as mild-moderate (logMAR scores less than the median of all individuals with VI) and severe (logMAR scores median or greater); and VI incidence as VI absence at baseline, but evident at follow-up. Age was stratified into 40 to 49 years, 50 to 64 years, and ≥65 years.

MAIN OUTCOME MEASURES

Rasch-transformed scores from the 32-item Impact of Visual Impairment (IVI) questionnaire were used to measure the "Reading," "Mobility," and "Emotional" domains of VRQoL. Multiple linear regression models determined the age-stratified associations of prevalent and incident VI with all 3 VRQoL outcomes, adjusted for potential confounders.

RESULTS

Of the 807 persons with prevalent VI, 55.9% had mild-moderate and 44.1% had severe VI. Compared with no VI, age-stratified analyses showed that VRQoL decrements were significant only in the older age groups (mild-moderate VI: 6.2% and 8.1% reduction in Mobility and Reading scores in those aged ≥ 65 years; severe VI: 8.5% to 13.4% reductions in the 3 VRQoL scores in those aged ≥ 50 years). This interaction with older age became more pronounced with incident VI (N = 168), where decrements in all 3 VRQoL domains were evident only in those aged ≥65 years compared with persons without incident VI.

CONCLUSIONS

Our results suggest that the VI-VRQoL associations are driven mainly by older individuals aged ≥65 years, highlighting the need for effective regular screening and early intervention modalities to prevent the presence and onset of VI, and subsequent VRQoL declines, in these individuals.

Computerized Adaptive Tests: Efficient and Precise Assessment of the Patient-Centered Impact of Diabetic Retinopathy

Purpose

Evaluate efficiency, precision, and validity of RetCAT, which comprises ten diabetic retinopathy (DR) quality of life (QoL) computerized adaptive tests (CATs).

Methods

In this cross-sectional clinical study, 183 English and/or Mandarin-speaking participants with DR (mean age ± standard deviation [SD] 56.4 ± 11.9 years; 38% proliferative DR [worse eye]) were recruited from retinal clinics in Singapore. Participants answered the RetCAT tests (Symptoms, Activity Limitation, Mobility, Emotional, Health Concerns, Social, Convenience, Economic, Driving, and Lighting), which were capped at seven items each, and other questionnaires, and underwent eye tests. Our primary evaluation focused on RetCAT efficiency (i.e. standard error of measurement [SEM] ± SD achieved and time needed to complete each CAT). Secondary evaluations included an assessment of RetCAT's test precision and validity.

Results

Mean SEM across all RetCAT tests was 0.351, ranging from 0.272 ± 0.130 for Economic to 0.484 ± 0.130 for Emotional. Four tests (Mobility, Social, Convenience, and Driving) had a high level of measurement error. The median time to take each RetCAT test was 1.79 minutes, ranging from 1.12 (IQR [interquartile range] 1.63) for Driving to 3.28 (IQR 2.52) for Activity Limitation. Test precision was highest for participants at the most impaired end of the spectrum. Most RetCAT tests displayed expected correlations with other scales (convergent/divergent validity) and were sensitive to DR and/or vision impairment severity levels (criterion validity).

Conclusions

RetCAT can provide efficient, precise, and valid measurement of DR-related QoL impact. Future application of RetCAT will employ a stopping rule based on SE rather than number of items to ensure that all tests can detect meaningful differences in person abilities. Responsiveness of RetCAT to treatment interventions must also be determined.

Translational Relevance

RetCAT may be useful for measuring the patient-centered impact of DR severity and disease progression and evaluating the effectiveness of new therapies.

Artificial intelligence for teleophthalmology-based diabetic retinopathy screening in a national programme: an economic analysis modelling study

BACKGROUND

Deep learning is a novel machine learning technique that has been shown to be as effective as human graders in detecting diabetic retinopathy from fundus photographs. We used a cost-minimisation analysis to evaluate the potential savings of two deep learning approaches as compared with the current human assessment: a semi-automated deep learning model as a triage filter before secondary human assessment; and a fully automated deep learning model without human assessment.

METHODS

In this economic analysis modelling study, using 39 006 consecutive patients with diabetes in a national diabetic retinopathy screening programme in Singapore in 2015, we used a decision tree model and TreeAge Pro to compare the actual cost of screening this cohort with human graders against the simulated cost for semi-automated and fully automated screening models. Model parameters included diabetic retinopathy prevalence rates, diabetic retinopathy screening costs under each screening model, cost of medical consultation, and diagnostic performance (ie, sensitivity and specificity). The primary outcome was total cost for each screening model. Deterministic sensitivity analyses were done to gauge the sensitivity of the results to key model assumptions.

FINDINGS

From the health system perspective, the semi-automated screening model was the least expensive of the three models, at US$62 per patient per year. The fully automated model was $66 per patient per year, and the human assessment model was $77 per patient per year. The savings to the Singapore health system associated with switching to the semi-automated model are estimated to be $489 000, which is roughly 20% of the current annual screening cost. By 2050, Singapore is projected to have 1 million people with diabetes; at this time, the estimated annual savings would be $15 million.

INTERPRETATION

This study provides a strong economic rationale for using deep learning systems as an assistive tool to screen for diabetic retinopathy.

FUNDING

Ministry of Health, Singapore.

Cataract Surgery and the 6-year Incidence of Age-Related Macular Degeneration in a Multiethnic Asian Cohort

PURPOSE

The aim of this study was to determine whether cataract surgery was associated with age-related macular degeneration (AMD) development in Asian patients.

DESIGN

Longitudinal cohort study.

METHODS

Participants from the Singapore Malay and Indian Eye Studies were recruited between 2004 and 2015. A total of 6790 late-AMD-free eyes from 3475 individuals were followed for 6 years on average. Multivariable regression analysis using generalized estimating equations determined associations between cataract surgery and the incidence of any, early, and late AMD.

RESULTS

The mean age (SD) of participants was 55.5 (9.1) years; 48.1% were male; 11.3% of eyes had cataract surgery recorded; incident any, early, and late AMD developed in 238 (3.6%), 222 (3.4%), and 29 (0.4%) eyes, respectively. Operated eyes had higher incidence of late AMD [1.4% vs 0.3%; adjusted risk ratio (RR): 3.47, 95% confidence interval (CI) 1.40-8.57], but not early AMD (6.0% vs 3.0%, adjusted RR: 1.12, 95% CI 0.76-1.64) or any AMD (6.9 vs 3.2%, adjusted RR: 1.23, 95% CI 0.85-1.78).

CONCLUSIONS

Our data are consistent with findings in population-based Caucasian studies that cataract surgery may be associated with incidence of late AMD. However, the absolute risk of late AMD development remains low and physicians should continue to balance the benefits and risks of cataract surgery in elderly patients.

Using Uniocular Visual Acuity Substantially Underestimates the Impact of Visual Impairment on Quality of Life Compared with Binocular Visual Acuity

PURPOSE

Although the impact of vision-related quality of life (VRQoL) is assessed optimally using binocular visual acuity (VA), uniocular VA remains the preferred measurement method in clinic-based and epidemiologic studies. We compared the impact of distance presenting binocular VA and uniocular VA in the better-seeing (better-eye VA) and worse-seeing (worse-eye VA) eye on VRQoL.

DESIGN

The Singapore Chinese Eye Study 2 (2015-2017), a population-based, cross-sectional study.

PARTICIPANTS

One thousand eight hundred twenty-two individuals (mean age, 66.2 years [standard deviation, 8.9 years]; 51.1% women) were included.

METHODS

Presenting uniocular VA and binocular VA were assessed using a logarithm of the minimum angle of resolution number chart at a distance of 4 m under standard lighting by trained and certified study optometrists. Multiple linear regression models were constructed to determine the independent associations between binocular VA, better-eye VA, and worse-eye VA and the outcome (VRQoL), adjusted for potential confounders, including age, gender, socioeconomic status, and presence of comorbidities. In addition, a cluster sandwich estimator was used to determine if any differences in β estimates between the associations were statistically significant.

MAIN OUTCOME MEASURES

Vision-related quality of life was measured using Rasch-transformed scores from the emotional, mobility, and reading domains of the Impact of Visual Impairment (IVI) questionnaire.

RESULTS

Although every 2-line increase (worsening) in binocular VA and uniocular VA was associated independently with decrements in emotional, mobility, and reading IVI scores (P < 0.05 for all), the reductions in all VRQoL domains were substantially lower (P < 0.1) when using either the better-eye VA (compared with binocular VA β-estimates, -27.8%, -19.4%, and -24.2% difference in emotional, mobility, and reading IVI scores, respectively) or worse-eye VA (compared with binocular VA β estimates, -38.9%, -58.1%, and -57.5% reduction in emotional, mobility, and reading IVI scores, respectively) to quantify vision loss.

CONCLUSIONS

Uniocular VA seems to underestimate the impact of vision loss on VRQoL indices compared with binocular VA. Our data suggest that researchers, clinicians, and policy planners should consider using binocular instead of uniocular measures of VA in patient-reported outcome evaluation of vision loss because it may better reflect its impact on VRQoL.

Prevalence, determinants and association of unawareness of diabetes, hypertension and hypercholesterolemia with poor disease control in a multi-ethnic Asian population without cardiovascular disease

Background

To explore the prevalence and determinants of unawareness of diabetes, hypertension and hypercholesterolemia and its association with poor disease control in a multi-ethnic Asian population without cardiovascular disease (CVD).

Methods

We included 6904 Chinese, Malay and Indian individuals (mean age [SD] 58.2 [10.2] years; 52.6% female) with diabetes, hypertension and/or hypercholesterolemia from the cross-sectional population-based Singapore Epidemiology of Eye Diseases study (2004–2011). Diabetes was defined as random blood glucose ≥ 11.1 mmol/L or HbA1c > 6.5% or self-reported use of diabetes medication; hypertension as systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg or self-reported use of anti-hypertensive treatment; and hypercholesterolemia as total cholesterol ≥ 6.2 mmol/L or self-reported use of lipid-lowering medications. Unawareness was based on participants’ answers to the questions: “Did your medical practitioner ever tell you that you have diabetes/hypertension/high cholesterol?” The determinants of unawareness, and its association with poor disease control, were assessed using multivariable binary logistic regression models adjusted for known potential confounders.

Results

Of the 2380 (34.5%), 5386 (78.0%) and 3607 (52.2%) with diabetes, hypertension and hypercholesterolemia, respectively, unawareness rates were 30.7%, 43.1% and 40.9%, respectively. Having a higher BMI, particularly if obese, and Malay ethnicity were associated with greater unawareness of diabetes; Malay and Indian ethnicities and current smoking with greater unawareness of hypertension; and education ≤6 years, current smoking, and blue collar jobs or unemployment with greater unawareness of hypercholesterolemia (all P < 0.05). Lack of awareness of each condition was independently associated with poorer disease control in the case of hypertension and hypercholesterolemia, while the converse was true for diabetes (all P < 0.05).

Conclusions

Unawareness of diabetes, hypertension, or hypercholesterolemia is high in Singapore, with risk factors varying across all three diseases, although Malay ethnicity is a consistent one. Unawareness was also associated with poor management for hypertension and hypercholesterolemia. Public health education and screening programs should target at-risk individuals, especially Malays, to reduce the likelihood of incident CVD.

Using Adherence-Contingent Rebates on Chronic Disease Treatment Costs to Promote Medication Adherence: Results from a Randomized Controlled Trial

BACKGROUND

Poor adherence to medications is a global public health concern with substantial health and cost implications, especially for chronic conditions. In the USA, poor adherence is estimated to cause 125,000 deaths and cost $US100 billion annually. The most successful adherence-promoting strategies that have been identified so far have moderate effect, are relatively costly, and raise availability, feasibility, and/or scalability issues.

OBJECTIVE

The main objective of SIGMA (Study on Incentives for Glaucoma Medication Adherence) was to measure the effectiveness on medication adherence of a novel incentive strategy based on behavioral economics that we refer to as adherence-contingent rebates. These rebates offered patients a near-term benefit while leveraging loss aversion and regret and increasing the salience of adherence.

METHODS

SIGMA is a 6-month randomized, controlled, open-label, single-center superiority trial with two parallel arms. A total of 100 non-adherent glaucoma patients from the Singapore National Eye Centre were randomized into intervention (adherence-contingent rebates) and usual care (no rebates) arms in a 1:1 ratio. The primary outcome was the mean change from baseline in percentage of adherent days at Month 6. The trial registration number is NCT02271269 and a detailed study protocol has been published elsewhere.

FINDINGS

We found that participants who were offered adherence-contingent rebates were adherent to all their medications on 73.1% of the days after 6 months, which is 12.2 percentage points (p = 0.027) higher than in those not receiving the rebates after controlling for baseline differences. This better behavioral outcome was achieved by rebates averaging 8.07 Singapore dollars ($US5.94 as of 2 November 2017) per month during the intervention period.

CONCLUSION

This study shows that simultaneously leveraging several insights from behavioral economics can significantly improve medication adherence rates. The relatively low cost of the rebates and significant health and cost implications of medication non-adherence suggest that this strategy has the potential to cost-effectively improve health outcomes for many conditions.

Is Myopia Associated with the Incidence and Progression of Diabetic Retinopathy?

PURPOSE

We sought to determine the association of refractive error and its associated determinants (axial length [AL], anterior chamber depth, and corneal curvature) with the incidence and progression of diabetic retinopathy (DR).

DESIGN

Population-based cohort study.

METHODS

A total of 1562 eyes of 840 individuals with diabetes and gradable retinal photographs (mean age [SD], 57.0 [8.3] years, 48.2% female) from the Singapore Malay and Indian Eye Studies at baseline (2004-2009) and follow-up (2011-2015) examinations were included in the analyses. Refractive error was calculated as sphere plus half negative cylinder, while AL, anterior chamber depth, and corneal curvature were assessed using optical biometry. Incident DR was defined as having no baseline DR and any DR at follow-up; incident vision-threatening DR as no baseline vision-threatening DR but present at follow-up; and DR progression as an increase in severity at follow-up from at least minimal baseline DR. Eye-specific data and generalized estimating equation models were used to account for between-eye correlation to determine the relationships between the exposures and outcomes, adjusted for traditional DR risk factors.

RESULTS

At follow-up, 164 of 1273 (12.9%) eyes had incident DR, 17 of 1542 (1.1%) eyes had incident vision-threatening DR, and 75 of 269 (27.9%) eyes with baseline DR experienced progression. A longer AL (per millimeter increase) (risk ratio 0.58 [95% confidence interval 0.38-0.88) was associated with a lower risk of incident DR. No other associations were found.

CONCLUSION

Our findings show that a longer AL is protective of incident DR.