General Ophthalmic Services Activity Statistics - England Analysis of sight test patient eligibility data Copyright 2012, The Health and Social Care Information Centre, Dental and Eye Care Team. All Rights Reserved. 1
The NHS Information Centre is England s central, authoritative source of health and social care information. Acting as a hub for high quality, national, comparative data, we deliver information for local decision makers, to improve the quality and efficiency of care. www.ic.nhs.uk Author: The NHS Information Centre, Dental and Eye Care Team Version: 1.0 Copyright 2012, The Health and Social Care Information Centre, Dental and Eye Care Team. All Rights Reserved. 2
Contents Background... 3 Comparison of Exeter sight test data with published data... 5 Background 1. The objective of General Ophthalmic Services (GOS) is to provide, through community optician practices, preventative and corrective eye care for children, people aged 60 and over, people on low incomes, and those suffering from, or pre-disposed to, eye disease. 2. Eye care services are available on-demand, largely in the high street from the private sector. In August 2008, the Primary Ophthalmic Services Regulations came into force in England. Full detail on the regulations can be accessed via the following link: www.opsi.gov.uk/si/si2008/uksi_20081186_en_1 3. These regulations for Government-funded services cover such issues as patient eligibility for sight tests, how patients apply for a sight test and eligibility for domiciliary sight tests. There are no reporting requirements explicitly set out in the regulations. 4. Activity data on NHS sight tests, optical vouchers and repairs are collected via a series of GOS forms: GOS1 NHS sight tests, including information on patient eligibility status. GOS2 The optical prescription or statement given to the patient. This form is not used as a basis for reporting. GOS3 NHS optical vouchers, including information on patient eligibility status. GOS4 NHS optical repair/replacement vouchers - including information on patient eligibility status and voucher type. GOS5 Private sights tests with partial help towards the full cost. GOS6 Domiciliary sight tests. 5. The large majority of forms are sent as paper returns to the relevant Primary Care Trust (PCT) who then input the information into the Central Ophthalmic Payments System (COPs). Practice around this input differs from area to area. Some PCTs input all forms into the Payments System whereas others make batched or aggregate returns which do not have the same level of detail as the full return. This last point has a major impact on our ability to report below a national total. Currently, information from GOS forms 1,3,4,5 and 6 are used in our publications. 6. The majority of sight test eligibility data for GOS Activity Statistics publications are collected via a manual collection co-ordinated by the Health and Social Care Information Centre s (HSCIC) Omnibus collections team. This is a 2 per cent sample of sight test data returning numbers of patients receiving NHS Sight Tests, by eligibility criteria. These data are referred to as Omnibus data. The Omnibus collection specifies that the sample must be a random sample of all sight tests in the PCT, though the HSCIC has no way to enforce this. Copyright 2012, The Health and Social Care Information Centre, Dental and Eye Care Team. All Rights Reserved. 3
7. Many of the organisations submitting data through Omnibus also submit some patient eligibility data on COPs, which is accessible via Open Exeter. The majority of these data represent a sample size of greater than 2 per cent. These data are referred to as Exeter data. Some of these data are collected through the electronic links pilot. 8. The electronic links pilot was started in May 2007, and offered practices with accredited systems to submit electronic claims directly to the Payments System. A small proportion of practitioners use this facility to input GOS1 and GOS6 forms directly into the system. Most PCTs include at least one practitioner that makes electronic submissions. The management of these data is less resource intensive than paper-based returns. Figures are subject to a series of automated validation checks that manage the quality of submitted information. Further, these data are individualised, rather than aggregated. 9. To test the quality of Omnibus data, we wanted to assess whether the quality of data collected through the Omnibus collections was substantially different to data available via Exeter. We under took an assessment of 2009/10 data, comparing data produces using various volumes of Exeter data with that published in the 2009/10 publication, which used our established methods and sources. 10. The results in this report are presented as an indication of variability in the Sight Tests sample based data so that users may be better informed as to their suitability for use in further analysis and decision making. 11. As a result of these analysis, the way in which sample based data are presented in the GOS Activity Statistics publication (in particular the annexes) has been changed for 2011/12 data. In addition, for some PCTs where Omnibus was previously the source for sight tests eligibility data, Exeter data were used instead to reduce the Omnibus data collection burden on PCTs. 12. The HSCIC continues to work with the Department of Health and other stakeholders to improve data quality while also maintaining a dataset that provides a useful insight into provision of General Ophthalmic Services in England. Copyright 2012, The Health and Social Care Information Centre, Dental and Eye Care Team. All Rights Reserved. 4
Comparison of Exeter sight test data with published data 13. NHS Sight Tests in England are available to patients who meet certain eligibility criteria. The HSCIC collects data on total NHS Sights Tests provided and splits the total according to the eligibility criteria creating data on Sight Tests by patient eligibility. Full data on the split by eligibility are not available so the HSCIC derives the data from samples. For the majority of PCTs, these data are from 2 per cent manual collection via our Omnibus system. For around 30 PCTs we source patient eligibility data from Exeter, as the PCT either provides a 100 per cent sample, or their sample is deemed representative enough not to require a separate manual collection. 14. We wanted to assess the impact of using Exeter as the source of patient eligibility samples for a greater number of PCTs. To test this we compared the published 2009/10 patient eligibility breakdown, derived using our existing collection arrangements, with breakdowns derived using different volumes of Exeter data according to specified sample size thresholds. 15. Under the various thresholds, for any of the PCTs in 2009/10 which had their patient eligibility data collected manually, if their Exeter patient eligibility sample size met the required threshold, we would use Exeter data as the source, rather than the manually collected data. Threshold 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% Description Patient eligibility sample size on Exeter greater than 0 per cent Patient eligibility sample size on Exeter greater than 10 per cent Patient eligibility sample size on Exeter greater than 20 per cent Patient eligibility sample size on Exeter greater than 30 per cent Patient eligibility sample size on Exeter greater than 40 per cent Patient eligibility sample size on Exeter greater than 50 per cent Patient eligibility sample size on Exeter greater than 60 per cent Patient eligibility sample size on Exeter greater than 70 per cent Patient eligibility sample size on Exeter greater than 80 per cent Patient eligibility sample size on Exeter greater than 90 per cent 16. From the data produced under each of the specified thresholds, we calculated national level patient eligibility data and compared it with the published 2009/10 figures (shown in table 1.0). We calculated the percentage point difference of percentage of patients in each category to the published figures. Copyright 2012, The Health and Social Care Information Centre, Dental and Eye Care Team. All Rights Reserved. 5
Table 1.0: NHS Sight Test patient eligibility, England 2009/10 Number and percent Aged 60 and over Children 0- Students 16-15 18 receiving income support 1 Prisoner on Leave receiving tax credit receiving Job Seekers Allowance Low income certificate holders (HC2) Registered blind/ partially sighted Diabetics/ Glaucoma sufferers Need complex lenses Closes relatives 40 & over of Glaucoma sufferers Number of NHS Sight Tests 2009/10 5,191,773 2,460,089 528,512 1,085,346 1,550 689,091 313,205 104,549 21,929 708,631 62,732 644,244 Proportion of NHS Sight Tests 2009/10 44.0 20.8 4.5 9.2 0.0 5.8 2.7 0.9 0.2 6.0 0.5 5.5 Proportion of NHS Sight Tests 2009/10 - Adjusted according to specified collection thresholds 0% 51.9 15.0 3.2 11.0 0.0 4.7 2.3 0.7 0.1 5.9 0.4 4.9 10% 42.7 20.6 4.4 8.9 0.0 6.0 2.8 0.9 0.1 7.0 0.5 6.1 20% 42.5 20.9 4.5 9.2 0.0 6.0 2.8 0.9 0.2 6.6 0.5 5.8 30% 43.4 20.8 4.5 9.2 0.0 5.9 2.7 0.9 0.2 6.4 0.5 5.6 40% 43.9 20.8 4.5 9.2 0.0 5.8 2.6 0.9 0.2 6.0 0.5 5.5 50% 44.0 20.8 4.5 9.2 0.0 5.8 2.7 0.9 0.2 6.0 0.5 5.5 60% 44.0 20.8 4.5 9.2 0.0 5.8 2.7 0.9 0.2 6.0 0.5 5.5 70% 44.0 20.8 4.5 9.2 0.0 5.8 2.7 0.9 0.2 6.0 0.5 5.5 80% 44.0 20.8 4.5 9.2 0.0 5.8 2.7 0.9 0.2 6.0 0.5 5.5 90% 44.0 20.8 4.5 9.2 0.0 5.8 2.7 0.9 0.2 6.0 0.5 5.5 1. Income Support includes patients receiving Pension Credit Guarantee Credit (PCGC) and also Income-related Employment and Support Allowance (ESA), which was introduced in October 2008 17. Table 1.1 and figure 1.0 show that it is the categories with the largest numbers, Aged 60 and over and Children 0-15 that bear the brunt of the impact at the lower thresholds in terms of percentage point change. However, it is clear that by this measure, even with a threshold as low as 10 per cent, all categories are within 2 percentage points of the published values, suggesting that overall distribution is only minimally affected. 18. One consideration should be that for a category with a small share of activity, a small percentage point change in percentage share can actually represent a relatively large shift for that particular category. Table 1.1: Percentage point change when compared with 2009/10 national level patient eligibility values, by qualifying sample size Percentage point Aged 60 and over Children 0- Students 16-15 18 receiving income support 2 Prisoner on Leave receiving tax credit receiving Job Seekers Allowance Low income certificate holders (HC2) Registered blind/ partially sighted Diabetics/ Glaucoma sufferers Need complex lenses Closes relatives 40 & over of Glaucoma sufferers 0% 7.95-5.82-1.29 1.80-0.01-1.13-0.40-0.22-0.10-0.09-0.13-0.55 10% -1.23-0.27-0.08-0.26 0.00 0.21 0.14-0.02-0.05 0.97-0.02 0.61 20% -1.41 0.05 0.06 0.05 0.00 0.20 0.13 0.03-0.03 0.58 0.00 0.33 30% -0.57-0.06-0.01 0.00 0.00 0.09 0.06 0.01-0.03 0.36 0.00 0.15 40% -0.05-0.01 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.04 0.00 0.01 50% 0.01-0.01 0.00 0.00 0.00 0.01 0.01 0.00 0.00-0.01 0.00 0.00 60% 0.01-0.01 0.00 0.00 0.00 0.01 0.01 0.00 0.00-0.01 0.00 0.00 70% 0.01-0.01 0.00 0.00 0.00 0.01 0.01 0.00 0.00-0.01 0.00 0.00 80% 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 90% 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 1. Income Support includes patients receiving Pension Credit Guarantee Credit (PCGC) and also Income-related Employment and Support Allowance (ESA), which was introduced in October 2008 Copyright 2012, The Health and Social Care Information Centre, Dental and Eye Care Team. All Rights Reserved. 6
Figure 1.0: Percentage point change when compared with 2009/10 national level patient eligibility values, by qualifying sample size 8.0 6.0 4.0 2.0 0.0-2.0-4.0-6.0-8.0 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% Aged 60 and over Children 0-15 Students 16-18 Prisoner on Leave receiving tax credit receiving Job Seekers Allowance Low income certificate holders (HC2) Registered blind/ partially sighted Diabetics/ Glaucoma sufferers Need complex lenses Closes relatives 40 & over of Glaucoma sufferers 19. Under the specified thresholds, the impact on absolute volumes of sight tests for each eligibility category is more substantial at the two lowest thresholds. Those with lower volumes of sight tests, such as Prisoner on Leave and Registered Blind/partially sighted are most affected as having smaller numbers of patients means they are more susceptible to variation in sample based data. 20. This summary analysis aims to demonstrate to users the level variability in the sample based data, depending on data source and sample size. We do not recommend that users use these results to recalculate any published data, they are presented only to indicate to users the quality of the sample based data. 21. Users should also consider that while this analysis compared data at a national level, it should be expected that changes to data source would have a more pronounced impact at PCT level. 22. As a result of this analysis and discussions with stakeholders, we have changed the way we present the sight test patient eligibility data in an attempt to ensure they are presented in an appropriate context and interpreted appropriately. These changes are discussed in further detail in the main report General Ophthalmic Services Activity Statistics England year ending 31 March 2012. 23. We continue to work with stakeholders to find ways to improve data quality and ensure the data retain their value to users. Copyright 2012, The Health and Social Care Information Centre, Dental and Eye Care Team. All Rights Reserved. 7
Published by the NHS Information Centre for health and social care Part of the Government Statistical Service Responsible Statistician Oliver Smith Service Manager For further information: www.ic.nhs.uk 0845 300 6016 enquiries@ic.nhs.uk Copyright 2012, The Health and Social Care Information Centre, Dental and Eye Care team. All rights reserved. This work remains the sole and exclusive property of the Health and Social Care Information Centre and may only be reproduced where there is explicit reference to the ownership of the Health and Social Care Information Centre. This work may be re-used by NHS and government organisations without permission. This work is subject to the Re-Use of Public Sector Information Regulations and permission for commercial use must be obtained from the copyright holder. Copyright 2012, The Health and Social Care Information Centre, Dental and Eye Care Team. All Rights Reserved. 8