Quality of Refractive Error Care Manual
Last edited 33 days ago by Anthea Burnett

This manual was developed by Anthea Burnett PhD and Ling Lee PhD, with major contributions by Myra McGuiness PhD, Beatrice Varga, Yadira Perez Hazel and Suit May Ho.
This work was funded by The Fred Hollows Foundation with support from the Australia Government through the Australian NGO Cooperation Program (ANCP). In collaboration with The University of New South Wales
Cover photos: Sam Phelps

Key Contacts

Anthea Burnett
Consultant, The Fred Hollows Foundation

Ling Lee
Consultant, The Fred Hollows Foundation


Dispensed spectacles: The glasses that have been prescribed, made and provided to a USP from an optical service.
Intra-service correlation: Describes how strongly the USP outcomes are from the same services.
Optical service: any place that provides refractive error services including refraction and optical dispensing. This might include privately owned stores, franchisee stores, vision centres, community health centre services, eye hospitals or secondary and tertiary hospitals.
Unannounced standardised patient (USP): An individual that has been trained to visit optical services in a standardised manner.

Index of acronyms & abbreviations

Analysis of variance
Dioptre cylinder
Dioptre sphere
Human research ethics committee
Institutional Review Board
Margin of Error
Quality of Refractive Error Care
Unannounced standardised patient
World Health Organization
Prism dioptres
There are no rows in this table

Q.REC: A manual for investigating the quality of refractive error care


Uncorrected refractive errors are the leading global cause of vision impairment, with 161 million people and an additional 510 million people living with distance and near vision impairment, respectively.1 In 2021, the United National General Assembly adopted a resolution committing the international community to provide eye health for all people living with vision impairment by 2030. To achieve such a target, the World Health Organization (WHO) stated that a commitment to Universal Health Coverage using an integrated people-centred eye care approach is the model of choice for quality and affordable eye care services, and that quality eye care services need to be provided according to population needs.2 To monitor progress and drive change towards Universal Health Coverage that includes the quality of eye care services, a broader set of measurement indicators are required.
Indicators should provide insights to shape change and stimulate action, track outcome progress and the quality of an intervention. Indicators have recently been established, to assess the ‘real world’ quality of refractive care, where care is a combination of prescribing and dispensing for refractive error. The Quality of Refractive Error Care (Q.REC) indicator provides information on the proportion of prescribed spectacles that are clinically optimal for patients, by comparing a baseline prescription to dispensed spectacles. The Q.REC study can also be used to assess core dimensions of quality, such as whether refractive error services are effective, equitable, safe and people-centred, and have the potential to identify aspects of clinical practice that require improvement, or further training.


A Q.REC study employs simulated patients — the gold standard for evaluating quality in clinical practice3 — and can be easily administered in urban settings. Simulated patients, or Unannounced Standardised Patients (USPs), are ‘actors’ who are trained to act covertly as patients in a standardised fashion, while observing clinical techniques and services provided. USPs have been used extensively in low- and middle-income countries, often in evaluating family planning, pharmaceutical dispensing patterns, and clinical prescribing patterns.4 Studies employing USPs have also previously been conducted to evaluate refractive error outcomes.5-7


It is anticipated that a Q.REC study will identify the proportion of people that are prescribed and dispensed spectacles appropriate for their refractive error needs. It can identify adherence to national guidelines or best practice and identify specific opportunities for quality improvement which can then be translated into policy changes or quality improvement initiatives. Q.REC studies can also be used to monitor ongoing delivery of quality refractive error care services, within the context of integrated people-centred eye care.
If a Q.REC study is executed well, the distinct advantage of employing USPs is that observation bias is minimised, as refractive error services are likely to modify their behaviours if they feel that they are being observed or assessed.


This protocol is unlikely to provide specific information for each facility as only a few USPs visit each service. Also, as all USPs will be adults, the findings might not be applicable to the quality of children’s refractive error care.
There is a possibility that USPs might be detected, and if so, the data should be excluded that consequently might broaden the range on Q.REC measurement. If there is a significant proportion of USP visits detect (i.e. >5%), and the USP continues to complete the visit and data is included, then there could be an overestimation on the Q.REC. USPs might also inadvertently mislead optical service staff to either perform better or poorer than usual behaviour. To reduce these potential biases, well-delivered USP training is essential.

Phase 1: Planning a Q.REC Project

Feasibility assessment

The following sections help to determine whether it is feasible to conduct a Q.REC Project. The main things to consider are how many optical services can be visited, the amount of study personnel required, the available equipment for recruitment, training and data collection, the time available of all personnel, and the support from relevant stakeholders.
Study Personnel
Study coordinator
Study optometrist(s) / refractionist(s)
Additional support can be sought:
People to assist with mapping all optical service providers in your setting
People to assist with translating documents
People to assist in advertising for USPs
People to assist in providing equipment or resources for training
Biostatistician to assist with data analysis
We recommend the study coordinator and study optometrist (who can be one person responsible for both roles) should be the key people/person that familiarises themselves with all the study materials including protocol, sample size calculator, budgeting template, ethics application, recruitment forms, optometrist training materials, USP training materials, data collections forms, and data quality control procedures.
The ideal study personnel to be involved with USP training, monitoring USP data collection and also completing some data collection would be eye health professionals with significant experience in refraction techniques and dispensing, likely optometrists or refractionists. Additional desirable skills would include teaching and research experience. Three optometrists/refractionists are required at optometrist and USP training, however, based on budget, time and availability, only one study optometrist might only be required during data collection. An additional optometrist will need to be on standby to conduct any additional baseline refractions required.
The number of USPs to recruit depends on the number of optical services that need to be visited and the available time to complete data collection. More information on ideal USPs is available in USP recruitment, (see USP Recruitment).

Provider mapping

Mapping out all the optical services within the study’s area of interest is important for determining the potential sample size, identifying the potential travel required by USPs and therefore budget implications. Determining a comprehensive list of all the optical services can be approached in multiple ways and is likely context-specific. This might include requesting information from governmental departments of business or health, using Google Maps or equivalent, or even travelling around to manually capture all services.
When conducting this exercise, be aware of the time in between mapping and beginning data collection. Optical services can be dynamic businesses where some will close and move location, while other new services might open. This has potential impact on the logistics and organising the USPs visiting services.

Equipment and resources required

The majority of information required to develop a protocol can be obtained from this document. Several equipment and resource lists can be developed for the different components of the Q.REC study. This includes:
translating documents
Consider which documents and forms will need translation to your local language. We expect for settings where English is not regularly used by optical services and potentially USPs, the following documents will require translation:
Participant Information Statements,
Consent and withdrawal forms,
Advertising flyers,
Training materials,
Data collection forms.
The above list is likely to be the minimum documents that are likely to need translation.
Once the documents have been translated, we also recommend back-translation into English by a different translator. This is to ensure the initial translation is appropriate. Both translators should have a least basic knowledge of refraction and refractive error terms.
Advertising for USPs
Consider how many and where flyers might be placed and online advertisements. Any advertisement will most likely need to be approved by the ethics committee
Screening and recruiting USPs
Consider where the potential USPs be screened, and by whom. The basic equipment needed is likely:
Retinoscope or autorefractor, and
Direct ophthalmoscope or indirect ophthalmic lenses and
Slit lamp.
Training study optometrists
At least a day of training optometrists in the Q.REC protocol so they are capable of providing USP training, baseline data collection and post-visit data collection Paper, laptops or mobile devices, an appropriate facility and per diems are likely required when training optometrists in the Q.REC protocol.
Training USPs including baseline data collection
Similar to training the study optometrist(s), an appropriate facility, paper, laptops or mobile devices and per diems for all study personnel and USPs should be considered. It is likely that USPs will be using their own mobile devices during field data collection, therefore, provision of mobile data also need to be considered.
Depending on your local context and targeted optical services, some optical services, as part of their standard practice, might conduct eye tests that are not related to prescribing for refractive error. For example, in Australia, optometrists in optical stores most commonly prescribe glasses to patients. However, when patients attend optical stores in Australia it is also common for the optometrist as standard practice to provide an eye test that include tests that check the health of the eyes. Tests might include slit lamp examination for the front of the eye, examining pupil reactions, checking eye pressures with contact or non-contact tonometry, or even checking the health of the retina with fundoscopy or photography. It is important to consider the extra tests unrelated to refraction that USPs can undergo to minimise their detection, and identify the tests that USPs can safely and appropriately refuse.
This planning exercise (Annex 1: Q.REC Planning) is to be completed by the study coordinator, refractionists/optometrists and those who have experience with visiting the optical services in the selected area. The exercise aims to identify all the potential eye examination techniques and equipment USPs might encounter at the optical service visits. This will then inform the equipment and space requirements when training the USPs. It is possible that your own facilities have limited equipment, however it is important that if the external services have other equipment, consider borrowing from other sources to demonstrate the USPs. As a last resort, images and videos can be shown to the USPs during training.
Post-visits data collection
At a minimum, a distance and near VA chart, a focimeter, ruler and laptop/mobile device to enter the data are required. Please review Form D: Assessment of Glasses, and consider whether there is quality control checking or refresher refraction training with USPs will be conducted to determine if any additional equipment is required.
Practical considerations
While the protocol can appear to be straightforward, do not underestimate the time planning and logistics might take to execute a Q.REC project without creating unintended bias. This might include:
Translating documents for ethics approval including protocol, consent forms, data collection forms, training materials.
Advertising, screening and recruiting USPs with a range of refractive error profiles
Ensuring all optometrists, USPs and equipment required are available for training, assisting with USP data collection and completing post-visit assessments
Scheduling USP visits to minimise being identified by optical services
Becoming familiar with online data collection tools

Calculation of sample size

The Q.REC Sample Size Calculator is used for estimating the proportion of spectacles that meet the selected/desired spectacle quality indicator for the targeted population. The calculation takes into account that there is clustering at the service level and clustering of the spectacles as USPs visit multiple stores. The Q.REC sample size calculator can be found here:
There are a few assumptions or considerations that need to be taken when calculating sample size:
The estimated proportion of spectacles estimated to pass/fail the chosen indicator (see next point about criteria available) of ‘good quality’. If the study’s area of interest has services that are not required to have formally trained professionals or if optical services are thought to be not well-regulated, then set it at 50% or 0.5. For a more developed and regulated optical services industry, then the estimated proportion of ‘good quality’ could be updated to at least 70% pass.
Two types of indicators have been developed to select one as the primary outcome, ‘Optimally prescribed spectacles’ and ‘Adequately prescribed spectacles’. For most studies, we recommend using the ‘Optimally prescribed spectacles’ indicator as the primary outcome. However, for settings where sphero-cylindrical lenses are rarely prescribed or available, the ‘Adequately prescribed spectacles’ indicator can be selected. The criteria details for each indicator can be found in the Annex (see Q.REC indicators).
The intraclass coefficient (ICC) needs to be selected. This coefficient represents how much the spectacles within each store may be linked, i.e. if 3 USPs are attending 1 optical service, are they more likely to get the 2nd and 3rd spectacles right because the 1st one was right?
If the primary outcome is to use the ‘optimally prescribed spectacles’ indicator and unsure of the link between USP visits to the same store, we recommend selecting the ICC to be 0.2.
If the primary outcome is to use the ‘optimally prescribed spectacles’ indicator and there is little link between USP visits to the same store, we recommend selecting the ICC to be either 0 or 0.1.
If the primary outcome is to use the ‘adequately prescribe spectacles’ indicator, then we recommend selecting the ICC to be either 0.2 or 0.3.
The margin of error (MoE) means the range around the estimated proportion of spectacles that pass the selected indicator. We have provided the options of 4%, 7% and 10% for selection. The smaller MoE selected, the narrower the range of estimated quality of refractive error, and the more accurate the results are likely to be. For example, if 50% of spectacles are estimated to be optimal quality (Q.REC indicator 1: Optimally prescribed spectacles) with a MoE of 4%, this means that with 95% confidence, it is estimated that 46 – 54% (50 ± 4%) of spectacles will pass the indicator. If an MoE of 10% were selected, then 40 – 60% of spectacles are estimated to pass the indicator. Please be aware the smaller the MoE desired, the more USP visits are required.

Figure 1 Example of Q.REC Sample Size Calculator
If there is an intention to compare sub-groups, for example, urban versus rural or private versus public services, the following calculator might not be sufficient. Additional sample size calculations will be required to ensure the sample size is sufficient to detect a differences between groups. However, clustering effects should also be taken into consideration.


The Q.REC Budget Template (Figure 2) can be used as a template for determining the study budget. The template will firstly require the number of spectacles per store, the number of optical services and total number of spectacles required (obtained from Q.REC Sample Size Calculator). There are a few assumptions or considerations that need to be taken when determining the study budget:
Reusing frames for budgeting purposes.
May need to have a couple of frames ‘on the go’.
The Q.REC Budget Template can be found here:
Note: Unlike the Q.REC Sample Size Calculator, the Budget Template will need to be downloaded to be modifiable (shown in Figure 3).

Figure 2: Example of Q.REC Budget Template
Figure 3: How to download Q.REC Budget Template

Approvals, support and buy-in

Once the feasibility of the Q.REC study and an approximate plan has been determined, consider the stakeholders that are needed for approval and/or support for the project. For the Q.REC study to be recognised and findings to be trusted, support and buy-in from the Department/Ministry of Health, optical associations or refraction training institutions should be considered.

Ethical considerations

Applying for ethics approval should be submitted as soon as possible. All USPs should provide written consent to accept being trained to act as a standardised patient and allow their refractive error and demographics information to be collected and reported. There are three approaches when applying for ethics approval to collect information from optical service visits:
Opt-out approach
The opt-out approach is recommended. This approach involves providing a participant information statement to all services (not just the ones selected) to inform the study is occurring in their area, they might be selected and then should be offered the option to opt-out of participation. An example Participant Information Statement and Opt-out form is provided in Annex 2: Templates: Optical Services.
This option reduces the risk of USPs being detected and enables to actively review USP detection after all visits have been completed.
A disadvantage of using the opt-out approach is the potential delay of USP visits as enabling services to have enough time to decide to opt-out is required. We recommend a minimum of two weeks. Furthermore, if opt-out slips are received during USP visits, previous data already collected from the stores may have to be discarded. To avoid having to discard data, opt-out forms can be designed to allow for already collected information to be kept unless the services explicitly request for data removal.
Depending on your human research ethics committee (HREC) or institutional review board (IRB), they are significantly more likely to grant approval with this approach compared to not seeking any consent or notification.
No consent sought
The main advantage of not seeking consent from optical services is that there is less likelihood for USPs to be detected and optical services to change their behaviour. There is also less preparation required before training USPs and begin data collection. However, depending on the HREC or IRB applied to, they may or may not grant approval with this approach.
Opt-in approach – Informed signed consent
If the HREC/IRB insist on seeking informed signed consent, we would recommend the following:
Increase the amount of time from consent to the first USP attending to reduce the risk of USPs being detected.
Increase the sample size to account for more USPs being detected, as data will need to be excluded from analysis if USPs are detected.

Phase 2: Preparing for data management

REDCap customisation

The basic Q.REC data collection tools have been developed using REDCap (Research Electronic Data Capture), a secure, web-based software platform designed to support data capture for research studies.8, 9 We identify these data collection tools as the Q.REC REDCap project. If REDCap is unavailable, this study can be conducted on paper.
Uploading the Q.REC REDCap Project
The Q.REC REDCap project is available as an XML file that can be uploaded to your institution’s hosted REDCap for use. Guidance on how to create a new project and upload the data collection tools can be reviewed in the video here:
For those familiar or interested in pursuing this research with REDCap, we understand that each project might slightly differ, therefore there are opportunities to customise the project within REDCap. Several of the potential customisations to be considered are presented in the Project Setup section of the project (Figure 4).
Figure 4: REDCap Project Setup Screen
REDCAP team roles
At a minimum, the study coordinator and study optometrist(s) should have an account to log into Redcap. Other co-investigators can be added. USPs are not required to have a Redcap account.
To add the study team and their individual accounts to the REDCap project, you will need to first request each of them to access to REDCap through your IT administration team that is hosting REDCap. Once provided access, each team member should receive an authentication link to activate their REDCap account. Once activated, then you can add them to the specific Q.REC REDCap project. Guidance on how to add study team members can be found here:
The principal investigator can decide who within the study team has access to some or all ‘Instruments’/forms, as well as what capabilities they have within the project. Limiting what team members can see or do can sometimes help with making it simpler to use. To update each study team’s roles and capabilities, use the User Rights application (Figure 5 – black outline). Guidance on how to use the User Rights application can be found here:
Figure 5: Relevant Applications in REDCap
Multi-site vs Single-site project
For a multi-site project, it is sometimes easier to keep track by entering the location(s) the USP has been allocated. A field within the “Project Admin” Instrument has been developed but will need to be updated with the location names.
If multiple sites have separate data collection teams, and each data collection team should only have access to the USP data for their site (recommended), then use the “DAGs” (Data Access Groups) application (Figure 5 – green outline). Guidance on how to use the DAGs application can be found here:
Translating within Redcap
To translate the USP patient information statement and consent form, data collection forms, and survey settings, use the Multi-Language Management application (Figure 5 – orange outline).
Guidance on how to use the Multi-Language Management application can be found here:

Making a duplicate project (for Form C only)
Before in-person training, the online training course should be accompanied with Form C: USP Optical Service Visit Checklist so USPs are introduced to what they will be using for data collection and have the opportunity to practice in their own time. To provide a practice form, there are two options
If USPs are collecting data in English: A separate REDCap project, ‘Q.REC Form C for Practice’ is available as an XML file can be uploaded to your institution’s hosted REDCap for use.
If USPs are collecting data in your local language: The most direct way is to duplicate your Q.REC REDCap project after the relevant forms have been translated using the Multi-Language Management application (see above), but only selecting Form C to be duplicated into a separate project and renaming the new project as ‘Q.REC Form C for Practice’.
Once Form C has been duplicated into a separate REDCap project, you can create a public link that will be emailed to the USPs. See the Section ‘Before in-person training’ for further details.
Updating Project Status from Development to Production Mode
When Q.REC REDCap Project has been uploaded into your host institution’s REDCap, it is currently set in “Development” mode. This means customisations can be made, changes can be tested and practice data can be entered without impacting data collection. Once familiar and happy with the project, “Move [the] project to production” mode, which can be found in the Project Setup section.

Phase 3: Recruiting for a Q.REC Project

Optical Services Recruitment

In this section, choosing the opt-out approach to recruiting optical services has been assumed.
Optical service inclusion/exclusion criteria
Table 1 Optical service inclusion and exclusion criteria
Provide refractive error services; both refraction and dispensing services
Optical service owner/manager opted out of the study
Personally known to the USP
Optical service had staff working across multiple services that have already been selected
There are no rows in this table

Once a comprehensive list of optical services has been compiled, all services should be sent a Letter of Invitation accompanied with the Participant Information Statement and Withdrawal Form. Once the information is received, a minimum of two weeks should be provided to services to allow for them to ask questions and/or withdraw (i.e. no USP visits, but this time period is a good opportunity to conduct optometrist and USP training). For all the services that do not return a Withdrawal Form, they can be selected to be part of the study by using a simple randomisation technique.
Please be aware, services should still able to withdraw even once USP visits and data collection has begun. If you suspect a significant proportion of services will withdraw after data collection has started, consider increasing the sample size by 5-10%.
If no consent is sought from optical services, no waiting period for data collection is required. If an opt-in approach (where services sign a consent form) is chosen, then we recommend similar waiting periods as the opt-out approach to minimise USPs being detected.

USP Recruitment

The ideal USP is someone with refractive error and no other ocular complications, is detail-oriented, capable of retaining reasonable volumes of information, is prepared to undergo training and be undercover when visiting optical services. If REDCap data collection is to be used, we also recommend the USP to be familiar with using mobile devices.
Including emmetropes as USPs are useful to assess the effectiveness of quality of care, where optical services acknowledge that spectacles would not benefit the patient and would not recommend that upon them.
USP inclusion/exclusion criteria
Table 2 Unannounced standardised patient inclusion and exclusion criteria
Age 18 years or above
Fluent native speaker of the primary language of the district
Good ocular health
Either in need of spectacle correction or emmetropic
Prior refractive eye surgery
Eye surgery within the past 3 months
Manifest or intermittent strabismus
An ocular or health condition that can cause variable spectacle prescription. Examples include (but not exhaustive): latent hyperope – where the amount of accommodation masks the hyperopia varies, keratoconus, pellucid’s marginal degeneration or other irregular corneal conditions, ocular surface disease, hydrops, glaucoma, binocular vision disorders, uncontrolled diabetes
Prior training in refraction or currently an eye care provider student
There are no rows in this table
Example Recruitment Advertisement

Recruitment Advertisement_Template.docx
8.4 MB

Screening and ocular health assessment

The screening is conducted by an eye health professional to assess whether the USP passes the inclusion and exclusion criteria for recruitment. As a variety of refractive error types are desired, assessing a potential USP’s current spectacles, a quick retinoscopy or an autorefraction will suffice for the screening.
Note: Retinoscopy is the only technique of the three capable of detecting keratoconus, except if your autorefractor is combined with a corneal topographer.
The ocular health examination includes an anterior and posterior eye examination. Anterior eye examination should be conducted with a slit lamp, and the posterior eye examination can be conducted dilated or undilated with direct or indirect ophthalmoscopy techniques.

Successful recruitment of USPs

Once potential USPs have been screened and identified as suitable, all should be invited to participate and provide consent to ensure they are clear on what being a USP involves, what the benefits and risks are, and information on data privacy. A sample USP consent form can be found in Annex 3: Templates: USPs.
We have developed electronic consent forms in REDCap. The content of the consent forms should match the consent forms submitted to the HREC/IRB and therefore might need to be edited if USP consent is to be completed electronically.
Generally a copy of the signed consent form should be provided to the USP. If REDCap for electronic signing of the consent forms is used, download each copy manually and email this to the USP. This will allow them the opportunity to provide written withdrawal if they choose to. If any USP decides to withdraw verbally, this should also be considered acceptable. However, please check with the HREC/IRB that this is an appropriate procedure.

Phase 4: Training for a Q.REC Project

Study Optometrist/Refractionist Training

Study optometrists are responsible for:
Conducting USP baseline refractions
Provide training to USPs on observing refraction equipment and techniques
Assessing whether USPs are ready to visit optical services and act as a USP
Assessing the quality of the spectacles that the USPs order and collect from optical services
Manage (can be with the study coordinator) ongoing data collection by USPs
It is important for study optometrists to understand what is also expected of the USPs to be able to assist with training and quality control. A checklist of what the study optometrists need to familiarise themselves with can be found in Annex 4: Study optometrists’ training checklist. This includes familiarising with the protocol, study materials and electronic data collection resources.
Training for the study optometrists should take approximately 1 day. The study team can also use this training as an opportunity to discuss any uncertainties and potential issues.

USP Training

When USPs are carefully and systematically trained, they are very capable of high accuracy over time. USP training is a blended program approach (i.e. part online, part in-person). In-person training should take approximately 3 days and USPs should bring a mobile or tablet device they will also use during data collection that can access WiFi or mobile phone data. A basic training schedule (that can be adjusted for your context) is outlined below:
Table 3 Example of Unannounced standardised patient training schedule
Before in-person training
Day 1
Day 2
Day 3
Online training course
Study overview
USP Q.REC quiz
Group discussion
Baseline refraction - data collection
Remaining Baseline refractions
Introducing other eye examination techniques
USP scripts and ‘entry plan’
Data entry (REDCap training and Form C)
QC: quality control
Additional baseline refractions (If need 4th refractions)
Scheduling optical service visits
There are no rows in this table

Before in-person training

It is recommended after USPs complete study consent and before in-person training, each USP reviews the online training materials and practices entering information into Form C. This will be the first introduction to the data collection form they will be using throughout the study. Two links should be emailed to them:
The Form C for Practice: Your project will have a unique link that can be copied and pasted into the USP emails.
The online training course is currently only available in English. If you do not think USPs would benefit from an online course in English, then consider adding an additional day to in-person training for the study team to go through the online training materials in your local language. If continuing to have a blended learning approach is preferred, then consider having the online training course translated into your local language. Please contact Dr Ling Lee at linglee@hollows.org.

In-Person Training

Study overview
This session is to provide USPs an overview of the entire Q.REC study, to either introduce the project to those who did not complete the online training course, or to recap Unit 1 from the online training course. It is also an opportunity to provide the setting’s specific details such as areas the USP are visiting, number of stores and visits.
USP Q.REC quiz and group discussion
The USP Q.REC quiz has been developed in REDCap. An example can be found in Annex 5: USP Q.REC Quiz. During study optometrist training, the study team should have learnt how to send out the USP Q.REC quiz to each USP. Email the quiz to each USP for them to complete it on their phone. Once complete, USPs receive a score out of 10 and the study team can also review their responses within their own REDCap account in the Reports section. Review the results of the quiz and discuss any errors with the USPs as a group. The USPs should also be given the opportunity to ask questions about the quiz, refraction techniques and the study protocol.
Baseline Refraction – data collection
The baseline refraction is essential for this study as all spectacles ordered from optical services will be compared to the baseline refraction. Each USP is to have a minimum of three subjective refractions conducted by three different optometrists/refractionists in the same setting. For each USP, the three refractions will be averaged to determine the baseline refraction. If two refractions have at least a 0.75 dioptre difference in the spherical or cylindrical power, a fourth refraction should be conducted to determine which refraction should not be included for the averaged baseline refraction. Additionally, if the lowest and highest pupillary distances (distance and near separately) recorded are greater than 2mm difference,10 repeat measurements are recommended and to be updated in Form A.
To assess and compare the three refractions (spherical and cylindrical powers, and pupillary distances only), a ‘Baseline Refraction Report’ in REDCap as an instrument is available to determine whether a fourth refraction is required.
Although the main goal of conducting baseline refractions is to obtain the spectacle prescription for each USP, it is also a training opportunity for USPs. This will be the first practical experience of how a comprehensive refraction examination is conducted after theoretical training.
It is important for the optometrists to perform the procedures and explain to the USP what they are doing at each point. While these might be more than what the optometrists perform in regular practice, this is to be as comprehensive as possible to introduce USPs to as many possibilities they might experience at optical service visits.
It is also important to complete the eye examination by discussing the USP’s vision needs to determine the spectacle lens types they would be suitable for (which might be more than one lens type). The discussion should demonstrate to the USP the level of communication appropriate for optimal patient-centred care.
At some points, and if possible, each optometrist will conduct and demonstrate different techniques to introduce USPs to the variation they might observe on their optical service visits. An example can be found in Annex 6: Baseline Refraction Data Collection. It is important to consider the resources required to offer all the different options for USPs to observe, and that the optometrists are confident in conducting the techniques with less frequently used equipment.
Introducing other eye examination techniques
This session is guided by the planning exercise (Annex 1: Q.REC Planning) conducted prior to training where the study team identified all the potential eye examination techniques and equipment USPs might encounter on their optical service visits. Examples might include (and not necessarily in this order): non-contact tonometry, slit lamp examination, direct ophthalmoscopy, binocular vision testing.
Here the optometrists/refractionists will explain to them the differences in refraction equipment and techniques, and which of those they should continue to undergo to avoid detection and other tests they should refuse. Examples of what to say to avoid detection should also be provided.
USP visit Scripts
The goal of the USP visit script is to ensure the approach into every store by each USP is consistent. When entering a service, each USP will need to request an eye test. If public health services that provides other speciality eye care services are being attended, for example cataract or laser surgery, then make sure USPs only request for a test for glasses. As symptoms are often different for different refractive error profiles, suggested USP responses have been developed for each refractive error type in Annex 7: USP Scripts.
If the USP observes they have been detected during the optical service visit, they should do the following:
If detected at entering and before any eye tests: Leave the service as smoothly and quickly as possible. Do not undergo any tests or order glasses. No data will be used except the acknowledgement of detection.
If detected during the eye tests: Do not order glasses and leave the service as smoothly and quickly as possible. No data will be used except the acknowledgement of detection.
If detected after glasses have been order: Continue to pick up glasses and request a written prescription. Only the written prescription and USP observation data will be used for analysis.
If detected during pick up of glasses: Continue to pick up glasses and request a written prescription. All data collected, including glasses assessment, will be used in the analysis.
Data entry (REDCap training and Form C)
This session is for USPs to gain practical experience in how to access Form C: USP Optical Service Visit Checklist on their phones and have more practice with data entry. Showing the video, How to enter in Form C, is a good demonstration. The USPs can then practice entering data from accessing the public link created in the REDCap Project, ‘Q.REC Form C for Practice’. Please ensure you separate entering mock data from the real data and live project.
QC: Quality Control
This session is to assess USPs’ readiness to conduct optical service visits and data collection. There are two options:
External Optical Service Visits
Here each USP and the study optometrist are to visit external optical services that are not selected as part of the Q.REC study data collection. These may be services that are within walking distance from where USP training has been conducted. Please also attempt to select services where the study optometrist is not known to the staff.
The study optometrist and the USP will go to the optical service together. The USP will request for an eye examination and have a refraction. The study optometrist, if possible, would request to be present during the eye examination. The USP should complete the examination as per the external optometrist’s procedures. Here the study optometrist observes whether the USP behaviour might lead to being exposed. Examples of behaviour might include:
Asking too many technical questions
Asking questions that might lead the optometrist to change their regular consultation procedures.
After the examination is complete, the USP should only ask for a prescription. No spectacles should be ordered. Once the USP and study optometrist leave the service, they both should complete the checklist in Form B: USP Practice and Quality Control.
Review Form B and discuss where the visit and observations could have been improved. Following the discussion, the study optometrist should complete the bottom section of Form B.
In some contexts, eye examination fees are required. If so, please consider this when you budget for a Q.REC project.
Internal Quality Control
Here each USP are to complete refractions with the study optometrists who have conducted training and baseline data collection within the training facilities. Here the study optometrist(s) will not explain the procedure to the USP and will follow the list of procedures outlined in Annex 9: Internal Quality Control Procedures and Scenarios. Following the refraction, the USP should request for a prescription and then complete the visit checklist in Form B: USP Practice and Quality Control.
This option is only possible if you can ensure the study optometrist(s) conducting the refractions can consistently include and exclude the procedures as outlined in Annex 9: Internal Quality Control Procedures and Scenarios.
This option is most efficiently completed when there are multiple refraction stations so more than one USP can be completing practice optical service visit at the same time. If the study optometrist is also conducting refraction(s), an additional observer to assess whether USPs are acting covertly should also be present. The additional observer can be another study optometrist or study coordinator or peer USP.
The USP should compare their checklist to a pre-filled “correct” form and discuss with the additional observer in areas where it can be improved. Following the discussion, the study optometrist/additional observer should complete the bottom section of Form B.
Scheduling optical service visits
The study team and USPs should work together to organise the optical service visit schedules. Some things to consider when scheduling:
Whether all recruited USPs will be visiting all optical services or will the USPs be grouped into teams to attend some of the optical services.
The availability of USPs (i.e. some might have part-time jobs or are studying)
Whether USPs will be visiting optical services on weekends and availability of study optometrists.
Days and times at which optical services might be closed
Whether appointments need to be arranged
Not all USPs visiting the same service visit at once or within a small timeframe to minimise risk of detection
Include travel time required – to each service and remote locations
For visiting services within the same city/town, we recommend a maximum of 4 service visits can be completed per day without significant fatigue experienced by the USP
For the first couple days of data collection, consider scheduling fewer service visits in one day for USPs to become comfortable and familiar with the processes.
A document detailing all USP schedules should be kept by the study coordinator. It is important that these are followed as closely as possible so the quality of data entry can be assessed appropriately.

Phase 5: Conducting field work

Field work includes USP visits and USPs returning to the study optometrist to have the spectacles assessed. After the first couple days of field work and data collection, it is important for the entire study team including USPs to reflect on their experiences, identify and resolve any issues for smoother running of the project.
Study staff will need to develop a system of tracking dispensed spectacles, so that they can be linked to the USP and Optical Service ID. However, to ensure the privacy of the optical services, no business names or their addresses should be kept once the study is complete.
If USPs return to the study optometrists with multiple pairs of glasses, it is important to continue to complete focimetry after vision and comfort are checked. It might practically appear more efficient to check vision and comfort with all pairs of glasses followed by focimetry. However, we do not recommend consecutively checking vision and comfort with all pairs of glasses at the same visit as checking vision and comfort with multiple pairs of glasses in a row is unlikely to provide reliable outcomes.

Assessing data quality

A Q.REC study is only as good as the quality of data collected and recorded. It is important to be familiar with each data collection form and the type or expected data for each variable/field, and to regularly conduct data quality control. We recommend data quality should be assessed at the following points and who is needed to be followed up with:
Table 4 Data quality assessment recommendations
Data collection tool
When to conduct data quality control
Data recorder, i.e. who should I follow up with
Form A: Baseline USP Data Record Form
As soon as baseline refractions are complete and entered into REDCap
Study optometrists
Form C: USP Optical Service Visit Checklist
During USP data collection to minimise USP recall bias.
Form D: Assessment of Glasses
During spectacle assessment when study optometrists record or enter and upload the data into REDCap.
Study optometrists
There are no rows in this table

Things to look out for across all data collection forms:
Missing data
REDCap has been designed where some fields/variables are compulsory to enter, therefore minimising missing data. However, it is still important to review the forms to see if there are any missing data, and to follow up with the corresponding person who entered the data.
Letters or symbols (string data) where there should be numbers
Most data are easier to analyse when numbers are entered in. Some typing errors (such as including letters or symbols) can cause number data to become text when downloaded as spreadsheets or data files for data analysis software like SPSS or STATA. Examples to look out for during data quality control include optometrists entering in ‘plano’ for spherical component of a prescription, or ‘N/A’ or ‘-‘ for no cylinder power or a near addition. All should be entered as ‘0’ or ‘0.00’
Entering in data electronically also increases risk of typing errors.
Examples include:
Additional ‘.’ in the number, i.e. “+5..00”
A space before or after a number
Text comments
Some data collection forms will have variables/fields where the data recorder can include some text. This might be in spaces where they select ‘Other’ and a new box appears to add some sort of description or note, or an ‘Additional Notes’ section. It is important to review the text comments to see if it can be updated to an existing checkbox, whether the context of the description is clearly understood, and to observe for signs where the data recorder might need additional assistance.
Additional things to look out for in Form A: Baseline USP Data Record Form
Inconsistency in the recorded USP age and/or gender across the (minimum) 3 Form A’s completed. You need to be certain that each study optometrist has entered the right information corresponding to the correct USP ID.
Missing or incorrect positive or negative signs in front of spherical power or near addition
Incorrect number data entry e.g. +12.5 entered rather than +1.25
Both distance and near (binocular) pupillary distances should be entered in (i.e. there should be no missing data) , even if only one type of single vision lenses is recommended.
Pupillary distances appear to be outside normal ranges of (47 – 75mm).
Near viewing distances appear to be outside traditional ranges of (30 – 55cm).
Optometrists should tick all the spectacle lens types, not just one, that they think the USP would be suitable for after they discuss with the USP their refractive error correction needs.
Additional things to look out for in Form C: USP Optical Service Visit Checklist:
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