Utility of EQ-5D to assess patients undergoing cataract surgery

Predictors of problems reported on the EQ-5D-3L dimensions among people with impaired vision in northern Portugal

BACKGROUND

The EQ-5D index often fails to detect the effect of ophthalmic diseases and sight loss. Investigating predictors of individual EQ-5D health dimensions might reveal the underlying reasons. The aim of this study was to investigate predictors of health dimension ratings obtained with the EQ-5D-3L from participants with impaired vision representing a spectrum of eye diseases.

METHODS

Observational cross-sectional study with participants recruited at four public hospitals in Portugal. Outpatients with visual acuity of 0.30 logMAR(6/12) or worse in the better-seeing eye were invited to participate. Participants completed two instruments: the EQ-5D-3L (measures participants' perceived health-related quality-of-life) and the Massof Activity Inventory (measures visual ability-ability to perform vision-related activities). This study used logistic regression models to identify factors associated with responses to the EQ-5D-3L.

RESULTS

The study included 492 participants, mean age 63.4 years (range = 18-93), 50% females. The most common diagnosis was diabetic retinopathy (37%). The mean visual acuity in the better seeing eye was 0.65 logMAR (SD = 0.48) and the mean visual ability was 0.62 logits (SD = 2.04), the correlation between the two was r = - 0.511 (p < 0.001). Mobility and self-care were the health dimensions with the fewest problems (1% reported extreme problems), anxiety and depression the dimension with the most problems (24% reported extreme problems). ROC curve analysis showed that the EQ-5D index was a poor predictor of cases of vision impairment whilst visual ability given was a good predictor of cases of vision impairment. Visual ability was an independent predictor of the response for all dimensions, higher ability was always associated with a reduced odds of reporting problems. The odds of reporting problems were increased for females in 3 out of 5 dimensions. Comorbidities, visual acuity and age-category were predictors of the odds of reporting problems for one dimension each.

CONCLUSIONS

The odds of reporting problems for the five health dimensions of the EQ-5D-3L were strongly influenced by the ability to perform vision-related activities (visual ability). The EQ-5D index showed poor performance at detecting vision impairment. These findings are informative and relevant for the clinic and for research evaluating the impact of eye diseases and disease treatments in ophthalmology.

Measurement Properties of the EQ VAS Around the Globe: A Systematic Review and Meta-Regression Analysis

OBJECTIVES

This study aimed to synthesize and evaluate published evidence on the measurement properties of the EQ VAS, a component of all EQ-5D questionnaires.

METHODS

This systematic review followed the Consensus-Based Standards for the Selection of Health Measurement Instruments guidelines. Five electronic databases were searched for EQ-5D-3L and EQ-5D-5L validation articles published from January 1, 2009, to November 5, 2019. Evidence for construct validity, test-retest reliability, and responsiveness was extracted from individual studies before being aggregated for evaluation of the populations represented by the studied samples. Multivariable logistic meta-regression was conducted to explore the effects of potential covariates on construct validity.

RESULTS

A total of 50 articles containing 488 studies, using samples drawn from 12 different populations, were identified. Generally, the quality of evidence was high for construct validity studies (n = 397) but only moderate for both test-retest reliability studies (n = 21) and responsiveness studies (n = 70). "Sufficient" construct validity of EQ VAS was found in 8 of 12 populations, "sufficient" test-retest reliability was found in 3 of 11 populations, and "sufficient" responsiveness was found in 5 of 12 populations. Meta-regression analyses suggested that construct validity studies from the Asian-Pacific region were more likely to show a negative rating compared with studies from Europe and North America.

CONCLUSION

The EQ VAS exhibits "sufficient" construct validity, "inconsistent" test-retest reliability, and "inconsistent" responsiveness across a broad range of populations. Additional studies are needed to explore the suboptimal validity of the EQ VAS in the Asian-Pacific region, whereas more high-quality validation studies are needed to assess its reliability and responsiveness.

Burden of visual impairment in mainland China: the Handan Eye Study and Beijing Eye Study

PURPOSE

To determine the impact of visual impairment (VI) on health-related quality of life (HRQoL) and to compare the health burden of VI in different areas in mainland China.

METHODS

A cohort of 6830 people from rural villages and a cohort of 3251 people from an urban city were included to receive comprehensive ophthalmologic examinations and complete the European Quality of Life-5 Dimensions 3 Levels (EQ-5D-3L) questionnaire. For urban and rural populations, a unified VI grouping standard was adopted: the eyes were classified into normal group, mild-moderate group, and severe group according to WHO standards, and then divided into 6 groups considering both eyes. We estimated the effects of VI on the EQ-5D index score using linear regression models and the association between VI and self-reported EQ-5D health problems using logistic regression models. Associations were assessed by the Spearman correlation coefficient.

RESULTS

The prevalence of VI and the index scores of EQ-5D-3L for each subgroup of VI were higher for the rural cohort. In these two cohorts, the severity of VI in rural population (Spearman r = 0.205; p < 0.0001) and urban population (Spearman r = 0.164; p < 0.0001) is correlated with the EQ-5D index score. In the rural cohort, the difference in index scores with bilateral severe VI compared to those without VI, after adjusting for covariates, was - 0.053 for the rural cohort and - 0.084 for the urban cohort, respectively. In the rural cohort, the odds ratio for bilateral severe VI was 4.39 for mobility, 6.33 for self-care, and 5.88 for usual activities. The incidence of anxiety or depression and pain or discomfort in the urban cohort was greater; the OR for bilateral severe VI in the urban cohort was 4.75.

CONCLUSIONS

VI has a negative impact on HRQoL in the rural and urban areas of China, especially in urban population. It is also more likely to cause anxiety or depression among the urban cohort, which deserves special attention.

Responsiveness of Vision-Specific and General Quality of Life Metrics to Ocular and Systemic Events in Patients with Uveitis

PURPOSE

To evaluate the responsiveness of quality of life (QoL) metrics to ocular and systemic events in patients with noninfectious uveitis.

DESIGN

Cohort study using randomized controlled trial data.

PARTICIPANTS

Patients with active or recently active intermediate, posterior, or panuveitis enrolled in the Multicenter Uveitis Steroid Treatment (MUST) Trial and Follow-up Study.

METHODS

Data on the 25-item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25), EuroQol Questionnaire (EQ-5D), and Short Form Survey Instrument (SF-36) were evaluated semiannually during the first 3 years after randomization. The impact of ocular (e.g., changes in visual acuity [VA], activity status, cataract surgery) and systemic events (e.g., infections requiring treatment) on the 6-month changes in QoL was assessed for each metric using generalized estimating equations.

MAIN OUTCOME MEASURES

The primary outcomes were the 6-month changes in vision-related (NEI-VFQ-25) and general health-related (EQ-5D index, SF-36 physical component summary [PCS]) QoL.

RESULTS

Changes in VA (adjusted change [aΔ]: 2.70 units per 5 letter change, P < 0.001), implant placement in at least 1 eye (aΔ: 5.50, P < 0.001), cataract surgery (aΔ: 3.01, P = 0.017), and quieting of all eyes active at the beginning of the interval (aΔ: 2.20, P < 0.010) were associated with improvements in the NEI-VFQ-25. Reductions in VA (aΔ: -0.014 per 5 letter decline, P = 0.003), infections requiring a prescription (aΔ: -0.024, P = 0.021), and incident uveitis activity in at least 1 eye (aΔ: -0.023, P = 0.031) were associated with declines in the EQ-5D index. Hospitalization (aΔ: -2.24, P = 0.019), infections requiring a prescription (aΔ: -1.00, P = 0.024), and vitreous hemorrhage in at least 1 eye (aΔ: -1.92, P = 0.021) were associated with declines in the SF-36 PCS. Declines in VA, initiation in IOP medication, and age were associated with changes in SF-36 PCS; however, the magnitude of the change was less than a single point.

CONCLUSIONS

The NEI-VFQ-25 was more sensitive to ocular changes than the general QoL metrics but less sensitive to acute systemic events. When performing QoL or cost-effectiveness analyses, it is important to consider the expected outcomes (e.g., ocular vs. systemic) to ensure that the selected measurement is sensitive enough to detect clinically important changes in disease status or effects of treatment.

EQ-5D-5L is More Responsive than EQ-5D-3L to Treatment Benefit of Cataract Surgery

BACKGROUND

It is not clear whether 5-level EQ-5D (EQ-5D-5L) utilities based on recently developed value sets are more responsive than 3-level EQ-5D (EQ-5D-3L) utilities.

OBJECTIVES

The study aims were to compare (1) the responsiveness of EQ-5D-5L and EQ-5D-3L utilities and (2) the responsiveness of these utilities with the Short Form-6 Dimension (SF-6D) and Health Utilities Index Mark 3 (HUI3) utilities to the treatment benefit of cataract surgery.

METHODS

A total of 148 patients were interviewed before and after their cataract surgery using EQ-5D-3L, EQ-5D-5L, SF-6D, and HUI3. Responsiveness was assessed for all measures using the mean change (post-treatment-pre-treatment), standardized effect size (SES), standardized response mean (SRM), and F-statistic.

RESULTS

Using the Singapore value sets, mean change for EQ-5D-3L and EQ-5D-5L utilities was 0.016 and 0.028, SES was 0.097 and 0.199; SRM was 0.091 and 0.196; and F-statistic was 1.2 and 5.7, respectively. Similar trends were observed using the UK/England EQ-5D value sets, although the magnitude was slightly smaller. The mean change, SES, SRM and F-statistics for SF-6D (UK value set) were 0.020, 0.234, 0.249, and 9.2, respectively. The values of mean change, SES, SRM and F-statistics for HUI3 (Canada value set) were 0.080, 0.472, 0.474, and 33.3, respectively.

CONCLUSIONS

The EQ-5D-5L utilities tend to be more responsive than the EQ-5D-3L utilities to treatment benefits of cataract surgery. The HUI3 utilities are more responsive than both the EQ-5D-5L and SF-6D, and SF-6D utilities may be slightly more responsive than the EQ-5D-5L for assessing patients undergoing cataract surgery.

Assessing the construct validity and responsiveness of Preference-Based Measures (PBMs) in cataract surgery patients

PURPOSE

The validity and responsiveness of the EQ-5D-3L in visual conditions has been questioned, inspiring development of a vision 'bolt-on' domain (EQ-5D-3L + VIS). Developments in preference-based measures (PBM) also includes the EQ-5D-5L and the ICECAP-O capability wellbeing measure. This study aimed to examine the construct validity and responsiveness of the EQ-5D-3L, EQ-5D-5L, EQ-5D-3L + VIS and ICECAP-O in cataract surgery patients for the first time, to inform choice of PBM for economic evaluation in this population.

METHODS

The analyses used data from the UK Predict-CAT cataract surgery cohort study. PBMs and the Cat-PROM5 [a validated measure of cataract quality of life (QOL)] were completed before surgery and 4-8 weeks after. Construct validity was assessed using correlations and known-group differences evaluated using regression. Responsiveness was evaluated using effect sizes and analysis of variance to compare change scores between groups, defined by patient-reported and clinical outcomes.

RESULTS

The sample comprised 1315 patients at baseline. No PBMs were associated with visual acuity and only the ICECAP-O (Spearman's rs =  - 0.35), EQ-5D-3L + VIS (rs =  - 0.42) and EQ-5D-5L (Value Set for England rs =  - 0.31) correlated at least moderately with the Cat-PROM5. Effect sizes of change were consistently largest for the EQ-5D-3L + VIS (range 0.34-0.41), followed by the ICECAP-O (range 0.20-0.34). Results indicated no improvement in responsiveness using the EQ-5D-5L (range 0.13-0.16) compared to the EQ-5D-3L (range 0.17-0.20).

CONCLUSIONS

Whilst no PBMs comprehensively demonstrated evidence of construct validity and responsiveness in cataract surgery patients, the ICECAP-O was the most responsive generic PBM to improvements in QOL. Surprisingly the EQ-5D-5L was not more responsive than the EQ-5D-3L in this setting.

Measurement Properties of Commonly Used Generic Preference-Based Measures in East and South-East Asia: A Systematic Review

OBJECTIVES

Our aim was to systematically review published evidence on the construct validity, test-retest reliability and responsiveness of generic preference-based measures (PBMs) used in East and South-East Asia.

METHODS

This systematic review was guided by the COSMIN guideline. A literature search on the MEDLINE, EMBASE, PsycINFO and PubMed databases up to August 2019 was conducted for measurement properties validation papers of the EuroQol-5 Dimensions (EQ-5D), Short Form-6 Dimensions (SF-6D), Health Utilities Index (HUI), Quality of Well-Being (QWB), 15-Dimensional (15D) and Assessment of Quality of Life (AQOL) in East and South-East Asian countries. Included papers were disaggregated into individual studies whose results and quality of design were rated separately. The population-specific measurement properties (construct validity, test-retest reliability and responsiveness) of each PBM were assessed separately using relevant studies. The overall methodological quality of the studies used in each of the assessments was also rated.

RESULTS

A total of 79 papers containing 1504 studies were included in this systematic review. The methodological quality was 'very good' or 'adequate' for the majority of the construct validity studies (99%) and responsiveness studies (61%), but for only a small portion of the test-retest reliability studies (23%). EQ-5D was most widely assessed and was found to have 'sufficient' construct validity and responsiveness in many populations, while the SF-6D and EuroQol-Visual Analog Scale (EQ-VAS) exhibited 'inconsistent' construct validity in some populations. Scarce evidence was available on HUI and QWB, but current evidence supported the use of HUI.

CONCLUSIONS

This systematic review provides a summary of the quality of existing generic PBMs in Asian populations. The current evidence supports the use of EQ-5D as the preferred choice when a generic PBM is needed, and continuous testing of all PBMs in the region.

A randomized controlled trial comparing femtosecond laser-assisted cataract surgery versus conventional phacoemulsification surgery

PURPOSE

To compare the clinical results of conventional phacoemulsification surgery (CPS) with femtosecond laser-assisted cataract surgery.

SETTING

Guy's & St Thomas' NHS Foundation Trust, London, United Kingdom.

DESIGN

Single-center prospective randomized interventional case-controlled trial.

METHODS

Patients undergoing cataract surgery were randomized to receive either CPS or femtosecond laser-assisted cataract surgery. The surgery was performed with a femtosecond laser (Lensx), and all operations were performed with a gravity-fluidics torsional phacoemulsification machine (Infiniti). The visual acuity, refraction, central corneal thickness (CCT), central foveal thickness (CFT), endothelial cell loss, and rates of intraoperative and postoperative events were recorded. Quality of life outcomes were measured with the EuroQOL 5 dimensions questionnaire (EQ-5D) and patient-reported quality of vision was assessed with a cataract surgery patient-reported outcome measures questionnaire (Cat-PROM5).

RESULTS

The study comprised 400 eyes of 400 patients who had CPS (n = 200) or femtosecond laser-assisted cataract surgery (n = 200). Seven patients (3.5%) in the femtosecond laser-assisted group were not able to complete the treatment and received CPS. The mean uncorrected distance visual acuity (logarithm of the minimum angle of resolution [logMAR]) 0.15 ± 0.21 (SD) and 0.15 ± 0.19 logMAR after CPS and femtosecond laser-assisted surgery, respectively (P = 1.0); the pinhole-corrected visual acuity was 0.04 ± 0.12 and 0.04 ± 0.12, respectively (P = 1.0); the increase in CCT was 13 ± 19 μm and 15 ± 25 μm, respectively (P = .5); and the endothelial cell loss was 9.7 ± 13.7 % and 10.2% ± 13.7, respectively (P = .76). The manifest refraction spherical equivalent error was -0.14 ± 0.60 diopters (D) after CPS and -0.12 ± 0.60 D after femtosecond laser-assisted surgery (P = .74); the mean change in CFT was 9 ± 35 μm and 6 ± 35 μm, respectively (P = .55); and the rate of posterior capsule rupture was 3% and 0%, respectively (P = .03).

CONCLUSIONS

This study confirms the nonsignificant differences between 2 treatment modalities, notwithstanding a significant reduction in posterior capsule ruptures in the femtosecond laser-assisted surgery group.

Randomized controlled trial evaluating a novel community eye care programme for elderly individuals with visual impairment

IMPORTANCE

The novel intervention was effective at improving compliance to appropriate tertiary eye care after community eye screening.

BACKGROUND

Elderly individuals from low socio-economic background with visual impairment (VI) often do not attend tertiary care, even if significant eye diseases are detected while in the community. We evaluate a novel incentive care scheme (ICS) to improve compliance to appropriate follow-up after community eye screening.

DESIGN

Randomized controlled trial in a population-based setting was conducted.

PARTICIPANTS

A total of 140 elderly individuals with VI (visual acuity <6/12, mean age ± SD = 66.6 ± 8.9 years, 46.4% female) were included.

METHODS

Participants were randomized to either ICS (N = 72) or usual care (UC; N = 68). ICS incorporated patient education, social support and financial assistance to assist individuals in attending tertiary eye care. UC comprised of a standard referral letter and advice.

MAIN OUTCOME MEASURE

Primary outcome included compliance to eye care referral. Secondary outcomes included best-corrected visual acuity and vision-related quality of life assessed at baseline and 3 months.

RESULTS

Participants receiving the ICS intervention had higher rates of compliance to tertiary eye care attendance compared to UC (31.9% vs. 16.2%, respectively, P = 0.027). While we observed an overall significant improvement in best-corrected visual acuity at 3 months in both groups (P < 0.05), we found no significant differences in Rasch-transformed vision-related quality of life scores between groups (all P > 0.05). Identified barriers for tertiary healthcare access included patient attitudes and financial- and health-related barriers.

CONCLUSION AND RELEVANCE

Our pilot RCT found that ICS improved adherence to appropriate tertiary eye care referrals after community eye screening in elderly people with VI.

Validation of Brunei's Malay EQ-5D Questionnaire in Patients with Type 2 Diabetes

Background

The Malay spoken in Brunei a South East Asian country where Malay is the national language is distinctive and different from Malay spoken in Malaysia, Singapore and Indonesia. This study aimed to develop a Brunei Malay version of the 5-level EQ-5D questionnaire (EQ-5D-5L) and to assess its psychometric properties among patients with type 2 diabetes mellitus (T2DM).

Methods

The Brunei Malay EQ-5D-5L was developed by culturally adapting two existing Malay versions. A total of 154 Bruneians with T2DM completed the questionnaire in two different points of time with one week apart. Known-groups validity of the utility-based EQ-5D-5L index and visual analogue scale (EQ-VAS) was evaluated by comparing subgroups of patients known to differ in health status. Test-retest reliability was assessed using the intraclass correlation coefficient (ICC) or Cohen’s kappa.

Results

As hypothesized, patients known to have ‘better’ health had higher EQ-5D-5L index scores than those having ‘worse’ health in all 7 known-groups comparisons. The hypothesized difference in the EQ-VAS scores was observed in only 4 of the 7 known-groups comparisons. Kappa values ranged from 0.206 to 0.446 for the EQ-5D-5L items; the ICC value for the EQ-5D-5L index and EQ-VAS was 0.626 and 0.521, respectively.

Conclusions

The utility-based EQ-5D-5L index appears to be valid and reliable for measuring the health of Brunei patients with T2DM. The validity of the EQ-VAS in Brunei requires further investigation.

The Effect of Maternal Death on the Health of the Husband and Children in a Rural Area of China: A Prospective Cohort Study

Objective

To examine the effects of maternal death on the health of the index child, the health and educational attainment of the older children, and the mental health and quality of life of the surviving husband.

Methods

A cohort study including 183 households that experienced a maternal death matched to 346 households that experienced childbirth but not a maternal death was conducted prospectively between June 2009 and October 2011 in rural China. Data on household sociodemographic characteristics, physical and mental health were collected using a quantitative questionnaire and medical examination at baseline and follow-up surveys. Multivariate linear regression, logistic regression models and difference-in-difference (DID) were used to compare differences of outcomes between two groups.

Findings

The index children who experienced the loss of a mother had a significantly higher likelihood of dying, abandonment and malnutrition compared to children whose mothers survived at the follow-up survey. The risk of not attending school on time and dropping out of school among older children in the affected group was higher than those in the control group during the follow-up. Husbands whose wife died had significantly lower EQ-5D index and EQ-VAS both at baseline and at follow-up surveys compared to those without experiencing a wife’s death, suggesting an immediate and sustained poorer mental health quality of life among the surviving husbands. Also the prevalence of posttraumatic stress disorder (PTSD) was 72.6% at baseline and 56.2% at follow-up among husbands whose wife died.

Conclusions

Maternal death has multifaceted and spillover effects on the physical and mental health of family members that are sustained over time. Programmes that reduce maternal mortality will mitigate repercussions on surviving family members are critical and needed.

A Vision "Bolt-On" Item Could Increase the Discriminatory Power of the EQ-5D Index Score

BACKGROUND

Recently, a vision "bolt-on" EuroQol five-dimensional questionnaire (EQ-5D) was developed and tentative utility values (i.e., a "value set") for this new descriptive system were estimated.

OBJECTIVES

To compare the discriminatory power of this bolt-on and standard utility-based EQ-5D health indices.

METHODS

Cross-sectional data on the (3-level) vision bolt-on EQ-5D were collected through face-to-face interviews with 500 and 336 individuals with and without visual impairment, respectively. To assess the discriminatory power of the vision bolt-on index relative to the standard EQ-5D index developed in the vision bolt-on valuation study, 16 pairs of mutually exclusive subgroups of individuals defined by the individuals' visual acuity and responses to the 14-item visual function questionnaire were compared pairwise. The absolute mean difference in the two index scores and the corresponding F statistic derived from the comparisons were used as measures of discriminatory power.

RESULTS

The absolute mean difference in the bolt-on index score was larger than that in the standard EQ-5D index score in 14 of the 16 comparisons. The bolt-on index score exhibited a larger F-statistic value than did the standard EQ-5D index score in all known-group comparisons, with the F-statistic ratio ranging from 0.415 to 0.770.

CONCLUSIONS

The vision bolt-on EQ-5D appears to be more discriminative than the standard EQ-5D in measurement of vision problems. Future studies should investigate the extent to which the vision bolt-on item can increase the sensitivity of the EQ-5D to vision change in interventional studies.

Can The EQ-5D Detect Meaningful Change? A Systematic Review

BACKGROUND

The EQ-5D is one of the most frequently used, generic, preference-based instruments for measuring the health utilities of patients in economic evaluations. It is recommended for health technology assessment by the National Institute for Health and Clinical Excellence. Because the EQ-5D plays such an important role in economic evaluations, useful information on its responsiveness to detect meaningful change in health status is required.

OBJECTIVE

This study systematically reviewed and synthesized evidence on the responsiveness of the EQ-5D to detect meaningful change in health status for clinical research and economic evaluations.

METHODS

We searched the EuroQol website, PubMed, PsychINFO, and EconLit databases to identify studies published in English from the inception of the EQ-5D until August 15, 2014 using keywords that were related to responsiveness. Studies that used only the EQ-VAS were excluded from the final analysis. Narrative synthesis was conducted to summarize evidence on the responsiveness of the EQ-5D by conditions or physiological functions.

RESULTS

Of 1401 studies, 145 were included in the narrative synthesis and categorized into 19 categories for 56 conditions. The EQ-5D was found to be responsive in 25 conditions (45 %) with the magnitude of responsiveness varying from small to large depending on the condition. There was mixed evidence of responsiveness in 27 conditions (48 %). Only four conditions (7 %) (i.e., alcohol dependency, schizophrenia, limb reconstruction, and hearing impairment) were identified where the EQ-5D was not responsive.

CONCLUSION

The EQ-5D is an appropriate measure for economic evaluation and health technology assessment in conditions where it has demonstrated evidence of responsiveness. In conditions with mixed evidence of responsiveness, researchers should consider using the EQ-5D with other condition-specific measures to ensure appropriate estimates of effectiveness. These conditions should be a main focus for future research using the new EQ-5D version with five response levels.

The clinical effectiveness and cost-effectiveness of second-eye cataract surgery: a systematic review and economic evaluation

BACKGROUND

Elective cataract surgery is the most commonly performed surgical procedure in the NHS. In bilateral cataracts, the eye with greatest vision impairment from cataract is operated on first. First-eye surgery can improve vision and quality of life. However, it is unclear whether or not cataract surgery on the second eye provides enough incremental benefit to be considered clinically effective and cost-effective.

OBJECTIVE

To conduct a systematic review of clinical effectiveness and analysis of cost-effectiveness of second-eye cataract surgery in England and Wales, based on an economic model informed by systematic reviews of cost-effectiveness and quality of life.

DATA SOURCES

Twelve electronic bibliographic databases, including MEDLINE, EMBASE, Web of Science, The Cochrane Library and the Centre for Reviews and Dissemination databases were searched from database inception to April 2013, with searches updated in July 2013. Reference lists of relevant publications were also checked and experts consulted.

REVIEW METHODS

Two reviewers independently screened references, extracted and checked data from the included studies and appraised their risk of bias. Based on the review of cost-effectiveness, a de novo economic model was developed to estimate the cost-effectiveness of second-eye surgery in bilateral cataract patients. The model is based on changes in quality of life following second-eye surgery and includes post-surgical complications.

RESULTS

Three randomised controlled trials (RCTs) of clinical effectiveness, three studies of cost-effectiveness and 10 studies of health-related quality of life (HRQoL) met the inclusion criteria for the systematic reviews and, where possible, were used to inform the economic analysis. Heterogeneity of studies precluded meta-analyses, and instead data were synthesised narratively. The RCTs assessed visual acuity, contrast sensitivity, stereopsis and several measures of HRQoL. Improvements in binocular visual acuity and contrast sensitivity were small and unlikely to be of clinical significance, but stereopsis was improved to a clinically meaningful extent following second-eye surgery. Studies did not provide evidence that second-eye surgery significantly affected HRQoL, apart from an improvement in the mental health component of HRQoL in one RCT. In the model, second-eye surgery generated 0.68 incremental quality-adjusted life-years with an incremental cost-effectiveness ratio of £1964. Model results were most sensitive to changes in the utility gain associated with second-eye surgery, but otherwise robust to changes in parameter values. The probability that second-eye surgery is cost-effective at willingness-to-pay thresholds of £10,000 and £20,000 is 100%.

LIMITATIONS

Clinical effectiveness studies were all conducted more than 9 years ago. Patients had good vision pre surgery which may not represent all patients eligible for second-eye surgery. For some vision-related patient-reported outcomes and HRQoL measures, thresholds for determining important clinical effects are either unclear or have not been determined.

CONCLUSIONS

Second-eye cataract surgery is generally cost-effective based on the best available data and under most assumptions. However, more up-to-date data are needed. A well-conducted RCT that reflects current populations and enables the estimation of health state utility values would be appropriate. Guidance is required on which vision-related, patient-reported outcomes are suitable for assessing effects of cataract surgery in the NHS and how these measures should be interpreted clinically.

STUDY REGISTRATION

This project is registered as PROSPERO CRD42013004211.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme.

Health burden associated with visual impairment in Singapore: the Singapore epidemiology of eye disease study

OBJECTIVE

To assess the impact of visual impairment (VI) on health-related quality of life and to compare the health burden of VI and other health conditions in Singapore.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

We studied the 10 009 adults (3353 Chinese, 3397 Indians, and 3259 Malays) who underwent a comprehensive eye assessment and completed the European Quality of Life-5 Dimensions (EQ-5D) questionnaire in the Singapore Epidemiology of Eye Disease Study.

METHODS

We estimated the effects of VI, obesity, hypertension, diabetes, and hyperlipidemia on the EQ-5D index score using linear regression models and the association between VI and self-reported EQ-5D health problems using logistic regression models. We compared prevalence-based quality-adjusted life-year (QALY) loss associated with VI and other health conditions. For each condition, QALY loss was calculated for 100 000 persons in 1 year using associated reduction in EQ-5D index score estimated in regression analysis as disutility.

MAIN OUTCOME MEASURES

The EQ-5D index score and annual QALY loss.

RESULTS

The EQ-5D index score decreased with increasing VI severity in all 3 ethnicities. For example, after adjusting for sociodemographic characteristics, the difference in EQ-5D index score between adults with bilateral severe VI and those without VI was -0.044 (95% confidence interval [CI], -0.089 to 0.001) in Chinese, -0.127 (95% CI, -0.237 to -0.017) in Indians, and -0.085 (95% CI, -0.148 to -0.022) in Malays. In all 3 ethnicities, VI was associated with reporting of problems in mobility (e.g., odds ratio [OR], 3.69 for Chinese with bilateral severe VI; 95% CI, 1.21-12.13) and usual activities (e.g., OR, 6.51 for Chinese with bilateral severe VI; 95% CI, 1.59-26.58). In Indians, VI was also associated with anxiety or depression (e.g., OR, 2.68 for bilateral severe VI; 95% CI, 1.11-6.50). The annual QALY loss associated with VI was 511.8 in Chinese, 608.8 in Indians, and 706.7 in Malays, greater than that associated with other health conditions examined in this study.

CONCLUSIONS

Visual impairment is associated with substantial health burden among Asians in Singapore. The relatively high burden of VI highlights the importance of VI prevention. The ethnic difference exhibited in this burden warrants further study.