A population-level post-screening treatment cost framework to help inform vision screening choices for children under the age of seven

PURPOSE/BACKGROUND

Visual acuity (VA) screening in children primarily detects low VA and amblyopia between 3 and 6 years of age. Photoscreening is a low-cost, lower-expertise alternative which can be carried out on younger children and looks instead for refractive amblyopia risk factors so that early glasses may prevent or mitigate the conditions. The long-term benefits and costs of providing many children with glasses in an attempt to avoid development of amblyopia for some of them needs clarification. This paper presents a framework for modeling potential post-referral costs of different screening models once referred children reach specialist services.

METHODS

The EUSCREEN Screening Cost-Effectiveness Model was used together with published literature to estimate referral rates and case mix of referrals from different screening modalities (photoscreening and VA screening at 2, 3-4 years and 4-5 years). UK 2019-20 published National Health Service (NHS) costings were used across all scenarios to model the comparative post-referral costs to the point of discharge from specialist services. Potential costs were compared between a) orthoptist, b) state funded ophthalmologist and c) private ophthalmologist care.

RESULTS

Earlier VA screening and photoscreening yield higher numbers of referrals because of lower sensitivity and specificity for disease, and a different case mix, compared to later VA screening. Photoscreening referrals are a mixture of reduced VA caused by amblyopia and refractive error, and children with amblyopia risk factors, most of which are treated with glasses. Costs relate mainly to the secondary care providers and the number of visits per child. Treatment by an ophthalmologist of a referral at 2 years of age can be more than x10 more expensive than an orthoptist service receiving referrals at 5 years, but outcomes can still be good from referrals aged 5.

CONCLUSIONS

All children should be screened for amblyopia and low vision before the age of 6. Very early detection of amblyopia refractive risk factors may prevent or mitigate amblyopia for some affected children, but population-level outcomes from a single high-quality VA screening at 4-5 years can also be very good. Total patient-journey costs incurred by earlier detection and treatment are much higher than if screening is carried out later because younger children need more professional input before discharge, so early screening is less cost-effective in the long term. Population coverage, local healthcare models, local case-mix, public health awareness, training, data monitoring and audit are critical factors to consider when planning, evaluating, or changing any screening programme.

The cost-effectiveness of different visual acuity screening strategies in three European countries: A microsimulation study

Childhood vision screening programmes in Europe differ by age, frequency and location at which the child is screened, and by the professional who performs the test. The aim of this study is to compare the cost-effectiveness for three countries with different health care structures.

We developed a microsimulation model of amblyopia. The natural history parameters were calibrated to a Dutch observational study. Sensitivity, specificity, attendance, lost to follow-up and costs in the three countries were based on the EUSCREEN Survey. Quality adjusted life-years (QALYs) were calculated using assumed utility loss for unilateral persistent amblyopia (1%) and bilateral visual impairment (8%). We calculated the cost-effectiveness of screening (with 3.5% annual discount) by visual acuity measurement at age 5 years or 4 and 5 years in the Netherlands by nurses in child healthcare centres, in England and Wales by orthoptists in schools and in Romania by urban kindergarten nurses. We compared screening at various ages and with various frequencies.

Assuming an amblyopia prevalence of 36 per 1,000 children, the model predicted that 7.2 cases of persistent amblyopia were prevented in the Netherlands, 6.6 in England and Wales and 4.5 in Romania. The cost-effectiveness was €24,159, €19,981 and €23,589, per QALY gained respectively, compared with no screening. Costs/QALY was influenced most by assumed utility loss of unilateral persistent amblyopia. For all three countries, screening at age 5, or age 4 and 5 years were optimal.

Despite differences in health care structure, vision screening by visual acuity measurement seemed cost-effective in all three countries.

A Comprehensive Overview of Vision Screening Programmes across 46 Countries

Purpose:

To describe and compare vision screening programmes and identify variance in number and type of tests used, timing of screening, personnel involved, monitoring and funding to be used as data for optimising, disinvesting or implementing future screening programmes.

Methods:

A questionnaire consisting of nine domains: demography & epidemiology, administration & general background, existing screening, coverage & attendance, tests, follow-up & diagnosis, treatment, cost & benefit and adverse effects was completed by Country Representatives (CRs) recruited from 47 countries.

Results:

The questionnaire was sufficiently completed for 46 Countries: 42 European countries, China, India, Malawi and Rwanda. Variation of provision was found in; age of screening (0–17 years), tests included (23), types of visual acuity (VA) test used (35 different optotypes), personnel (13), number of screens per child (median 5, range 1–32), and times VA tested (median 3, range 1–30). Infant screening is offered in all countries, whereas childhood vision screening is offered at least once in all countries, but not all regions of each country. All 46 countries provide vision screening between the ages of 3–7 years. Data on screening outcomes for quality assurance was not available from most countries; complete evaluation data was available in 2% of countries, partial data from 43%.

Conclusion:

Vision screening is highly variable. Some form of VA testing is being undertaken during childhood. Data collection and sharing should be improved to facilitate comparison and to be able to optimise vision screening programmes between regions and countries.

Effectiveness of routine population-wide orthoptic preschool vision screening tests at age 6-24 months in the Netherlands

Purpose

The effectiveness of preverbal orthoptic tests at age 6, 9, 14 and 24 months in population‐wide screening was assessed.

Methods

Two consecutive birth cohorts at 134 centres were compared. At general health screening visits, children born July–December 2011 were vision screened four times between 6 and 24 months with inspection, pupillary reflexes, eye motility, Hirschberg, cover test and monocular pursuit. Children born January–June 2012 were vision screened at general screening visits only in case of visually apparent abnormalities or positive family history. After referral, cause and severity of amblyopia were determined. Visual acuity was measured in all children at 36 and 45 months.

Results

The control and intervention group comprised 5649 versus 5162 children. Amblyopia was diagnosed in 185 (3.3%) versus 159 children (3.1%), outside of screening in 21 (11.4%) versus 25 (15.7%). Between 6 and 24 months, 44 (23.8%) versus 27 (17%) (RR = 0.67 [95% CI 0.42, 1.09]) were referred and after visual acuity (VA) measurement 120 (64.9%) versus 107 (67.3%). Of 109 versus 108 children with refractive or bilateral amblyopia, 94 (86.2%) versus 92 (85.2%) were detected with VA measurements. Visual acuity of the amblyopic eye, after referral, was not significantly different between groups (p 0.896), nor was the time to amblyopia diagnosis (intention to screen [p 0.55]; per protocol [p 0.11]).

Conclusion

The effectiveness of vision screening was not influenced by omission of orthoptic tests at general health screening at 6–24 months. Refractive and bilateral amblyopia were almost exclusively found by VA measurements.

Implementation of paediatric vision screening in urban and rural areas in Cluj County, Romania

BACKGROUND

In 2018 and 2019, paediatric vision screening was implemented in Cluj County, Romania, where universal paediatric vision screening does not yet exist. We report on the preparation and the first year of implementation.

METHODS

Objectives, target population and screening protocol were defined. In cities, children were screened by kindergarten nurses. In rural areas, kindergartens have no nurses and children were screened by family doctors' nurses, initially at the doctors' offices, later also in rural kindergartens. CME-accredited training courses and treatment pathways were organised. Implementation was assessed through on-site observations, interviews, questionnaires and analysis of screening results of referred children.

RESULTS

Out of 12,795 eligible four- and five-year-old children, 7,876 were screened in 2018. In the cities, kindergarten nurses screened most children without difficulties. In Cluj-Napoca 1.62x the average annual birth rate was screened and in the small cities 1.64x. In the rural areas, however, nurses of family doctors screened only 0.49x the birth rate. In 51 out of 75 rural communes, no screening took place in the first year. Of 118 rural family doctors' nurses, 51 had followed the course and 26 screened children. They screened only 41 children per nurse, on average, as compared to 80 in the small cities and 100 in Cluj-Napoca. Screening at rural kindergartens met with limited success. These are attended by few children because of low population density, parents working abroad or children being kept at home in case of bad weather and road conditions.

CONCLUSIONS

Three times fewer children were screened in rural areas as compared to urban areas. Kindergartens in rural areas are too small to employ nurses and family doctors' nurses do not have easy access to many children and have competing healthcare priorities: there are 1.5x as many family doctors in urban areas as compared to rural areas. For nationwide scaling-up of vision screening, nurses should be enabled to screen a sufficient number of children in rural areas.

Cost-Effectiveness of Neonatal Hearing Screening Programs: A Micro-Simulation Modeling Analysis

Supplemental Digital Content is available in the text.

Early detection of neonatal hearing impairment moderates the negative effects on speech and language development. Universal neonatal hearing screening protocols vary in tests used, timing of testing and the number of stages of screening. This study estimated the cost-effectiveness of various protocols in the preparation of implementation of neonatal hearing screening in Albania.

High rate of failed visual-acuity measurements with the Amsterdam Picture Chart in screening at the age of 36 months

Purpose

In the Netherlands, youth health care physicians and nurses screen all children for general health disorders at Child Health Care Centers. As part of this, the eyes are screened seven times, with the first visual acuity (VA) measurement at 36 months with the Amsterdam Picture Chart (APK). The suitability of the APK has been questioned.

Methods

Children born between July 2011 and June 2012 born in the provinces Drenthe, Gelderland and Flevoland and invited for screening at 36 months were eligible. Parents were sent the APK picture optotypes to practise with their children in advance. Data were collected from electronic screening records. The Dutch vision screening guideline prescribes that children with VA <5/6, or one line interocular difference (not logMAR, however) should be retested or referred.

Results

Of 10 809 eligible children, 1546 did not attend and 602 attended but had no VA measurement at age 36 months, 247 of these were under orthoptic treatment. Of the 8448 children examined, VA was sufficient in 5663 (67.0%) and insufficient in 1312 (15.5%). In 1400 (16.6%), the measurement of VA itself failed. In 73 (0.9%), data were missing. Of the 216 children with 2 failed VA measurements, 150 (69%) were not referred, and measurement of VA was deferred to the next general screening examination at 45 months.

Conclusion

Although most parents had practised the APK picture optotypes at home with their children, the rate of failed APK measurements plus the measurements with insufficient VA was 32.1% at 36 months. Similar rates have previously been reported for Lea Symbols and HOTV, permitting the conclusion that measurement of VA at the age of 36 months cannot be recommended as a screening test in the general population.

Semistructured Observation of Population-based Eye Screening in The Netherlands

BACKGROUND

In the Netherlands, youth-healthcare (YHC) physicians screen children 7 times for vision disorders between the ages of 1 and 60 months. Examination consists of inspection of the external structures of the eye, fundus red reflex, Hirschberg test, pupillary reflexes, cover-uncover test, alternating-cover test, eye motility, monocular pursuit, and, from 36 months onwards, visual acuity (VA). We observed how well these tests are done.

METHODS

Screening test performance was assessed with semistructured observations. Two orthoptic students developed a semistructured observation form. In addition to extensive instructions from an orthoptist and YHC-physicians instructor, they attended 2 one-day courses for YHC physicians. Tests were assessed using criteria based on the Dutch Child Vision Screening Guideline version 2010 and the Dutch Manual for Orthoptic Examination. Type of chart, testing distance, and starting eye were recorded for VA measurements. The observations in the first week were done simultaneously by the two observers and checked for concordance.

RESULTS

Concordance between the two observers was good. Twenty-five YHC physicians were observed during 100 days in total. Two physicians were excluded because they examined few children. The remaining 23 physicians examined 329 children, of whom 82 were aged 1-4 months, 157 aged 6-24 months, and 90 aged 36-45 months of age. Fundus red reflex was performed in 89% of children, Hirschberg test in 88%, pupillary reflexes in 14%, cover-uncover test in 65%, alternating-cover test in 62%, eye motility in 68%, monocular pursuit in 23%, and VA at 36-45 months in 94%. Forty-eight percent of cover-uncover tests, 36% of alternating-cover tests, and 7% of eye motility tests were performed correctly. VA was measured at 3 meters in 2%, others at 5 meters in accordance with the guideline. A picture chart was used instead of the Landolt-C at the age of 45 months in 23%. VA measurements were performed correctly in 89%, fundus red reflex in 89%, and Hirschberg test in 87%.

CONCLUSION

Hirschberg test, fundus red reflex, and VA were adequately tested in most cases. Cover-uncover test, alternating-cover test, and eye motility were often performed inadequately. Pupillary reflexes were skipped often as room lights could not be dimmed.

The effect of omitting an early population-based vision screen in the Netherlands: A micro-simulation model approach

Objective To estimate the effect of omitting an individual screen from a child vision screening programme on the detection of amblyopia in the Netherlands. A previous study (Rotterdam Amblyopia Screening Effectiveness Study) suggested that the three screens carried out between 6 and 24 months contributed little. Methods We developed a micro-simulation model that approximated the birth-cohort data from the previous study, in which 2964 children had completed follow-up at age 7, and 100 amblyopia cases were detected. Detailed data on screens, referrals, and orthoptic follow-up, including the cause of amblyopia, were available. The model predicted the number of amblyopia cases detected for each screen and for the entire screening programme, and the effect of omitting screens. Incidence curves for all types of amblyopia caused by strabismus, refractive anomalies or by both were estimated by approximation of the observational data, in conjunction with experts' estimations and the literature. Results We calculated mean actual sensitivity per screen per type of amblyopia, and the effect per screen. Screening at 24 months was found to be least effective. The impact on the screening programme, estimated by summing the effectiveness per screen, omitting the 24-month screen, was a reduction of 3.4% (57 vs. 59 cases) in the number of detected cases of amblyopia at age 5. Conclusion The effectiveness of the Dutch vision screening programme would hardly be affected by omission of the 24-month screening examination. A disinvestment study is warranted.

Effect of omission of population-based eye screening at age 6-9 months in the Netherlands

PURPOSE

To investigate omission of population-based eye screening at age 6-9 months in the Netherlands.

METHODS

Prospective population-based consecutive birth cohort study was used. In two consecutive birth cohorts, children were eye screened at 1-2 and 3-4 months, but at general-health screening at 6-9 months, the second cohort was not eye screened, unless anything conspicuous was noted or in case of positive family history. Data were collected from screening records and anonymous questionnaires. Semi-structured daylong observations were made of physicians examining children aged 0-4 years, including children from the cohorts, by two orthoptic students.

RESULTS

58 of 6059 children (0.96%), in the screened, and 48 of 5482 children (0.88%) in the unscreened group were referred to orthoptist or ophthalmologist, mostly for observed strabismus. Amblyopia, all combined with strabismus, was diagnosed in ten screened (0.17%) versus six unscreened children (0.11%). Most physicians found preverbal examinations and decisions to refer difficult. The observations by orthoptic students revealed that cover test, pupillary reflexes, pursuit movements and eye motility were frequently performed inadequately, contrary to the Hirschberg test, at this age.

CONCLUSION

The screened and unscreened group differed little regarding the number of children referred and found to have amblyopia. Referral was mostly based on observed strabismus.

Inventory of current EU paediatric vision and hearing screening programmes

OBJECTIVE

To examine the diversity in paediatric vision and hearing screening programmes in Europe.

METHODS

Themes for comparison of screening programmes derived from literature were used to compile three questionnaires on vision, hearing, and public health screening. Tests used, professions involved, age, and frequency of testing seem to influence sensitivity, specificity, and costs most. Questionnaires were sent to ophthalmologists, orthoptists, otolaryngologists, and audiologists involved in paediatric screening in all EU full-member, candidate, and associate states. Answers were cross-checked.

RESULTS

Thirty-nine countries participated; 35 have a vision screening programme, 33 a nation-wide neonatal hearing screening programme. Visual acuity (VA) is measured in 35 countries, in 71% of these more than once. First measurement of VA varies from three to seven years of age, but is usually before age five. At age three and four, picture charts, including Lea Hyvarinen, are used most; in children over four, Tumbling-E and Snellen. As first hearing screening test, otoacoustic emission is used most in healthy neonates, and auditory brainstem response in premature newborns. The majority of hearing testing programmes are staged; children are referred after 1-4 abnormal tests. Vision screening is performed mostly by paediatricians, ophthalmologists, or nurses. Funding is mostly by health insurance or state. Coverage was reported as >95% in half of countries, but reporting was often not first-hand.

CONCLUSION

Largest differences were found in VA charts used (12), professions involved in vision screening (10), number of hearing screening tests before referral (1-4), and funding sources (8).

Effective corneal collagen crosslinking in advanced cases of progressive keratoconus

PURPOSE

To evaluate the 1-year results of corneal collagen crosslinking (CXL) in mild to moderate cases and advanced cases of progressive keratoconus.

SETTING

Department of Ophthalmology, University Medical Center Utrecht, the Netherlands.

DESIGN

Retrospective cohort study.

METHODS

Eyes with progressive keratoconus had CXL between January 2010 and April 2011. Patients were divided into 2 subgroups as follows: Group 1, mild to moderate keratoconus with a preoperative maximum keratometry (K) of less than 58.0 diopters (D), and Group 2, advanced keratoconus with a maximum K of 58.0 D or more. Visual acuity, refraction, and elevation-based topography were evaluated at baseline and 12 months after CXL.

RESULTS

The study comprised 53 eyes of 42 patients. In the overall group, progression was halted in 48 eyes (91%). The CXL-induced corneal flattening occurred in 11 (42%) of 26 eyes in Group 1 and 20 (74%) of 27 eyes in Group 2. Five of 7 keratoconus indices improved 12 months after CXL. The failure rate was comparable in the subgroups (3 eyes in Group 1, 2 eyes in Group 2). No major complications occurred in either subgroup.

CONCLUSIONS

Stabilization after CXL was achieved in mild to moderate cases and advanced cases of progressive keratoconus. The amount of failure was comparable in the 2 subgroups. The CXL-induced flattening was more pronounced in the advanced subgroup.