1. Predictive Models for Health and Social Care: A Feasibility Study
Authors: Bardsley M, Billings J, Dixon J, Georghiou T, Lewis GH, Steventon A (2011) ‘Predicting who will use intensive social care: case finding tools based on linked health and social care data’, Age and Ageing 40(2):
February 2011

2. Background
Key points
Evidence that admission to a nursing home can be delayed or avoided by means of preventative ‘upstream’ interventions
Increasingly, public services will have to become more proactive in identifying and managing risk in older people, in order to mitigate them as much as possible
It will be important to identify and support not just those at highest risk of these costs, but also those currently at lower risk who might become higher risk in future
Current methods of assessing risk largely rely on face to face assessments.  In health care this approach has been shown to be less accurate at predicting predicting future events (hospitalisation) compared to statistical models.

3. Predictive modelling
BMJ in paper* in 2002 showed Kaiser Permanente in California seemed to provide higher-quality healthcare than the NHS at a lower cost. Kaiser identify high risk people in their population and manage them intensively to avoid admissions
• Modelling aims to identify people at risk of high costs in future
Use pseudonymous, person-level data
In health sector a number of predictive models are available e.g. PARR++ and the combined model.
*Getting more for their dollar: a comparison of the NHS with California's Kaiser Permanente BMJ 2002;324:

4. Predictive Models Identify who will be where on next year’s Kaiser Pyramid

5. Patterns in routine data to identify high-risk people next year

6. Patterns in routine data to identify high-risk people

7. Patterns in routine data to identify high-risk people

8. Distribution of Future Utilisation is Exponential

9. Can we predict costly social care events in the same way?
Do the data exist in local systems?
Can we extract individual, person-level data?
Can we link a wide range of health and social care data at the person level?
Are the data accurate and complete enough to use?
Can we build a valid statistical model?

10. Feasibility Project
Funded by Department of Health Care Services Efficiency Delivery (CSED) programme over 18 months
Worked with 5 sites to extract data sets
Extracted person-level health & social care data sets
Linked data from GP records (2 sites); GP register (all sites); Hospital (all sites); Social Care (all sites)
Undertook exploratory analyses and ran a range of models
Tested the impacts of different data sets on the models

11. Using health and social care data to predict health and social care use

12. Using routine data
Less labour intensive so they can stratify the population systematically and repeatedly
Avoid “non-response bias”
Can identify people with lower, emerging, risk
Important issues of confidentiality and consent to consider
Linking data sources at individual level across health and social care is problematic where there is no NHS number in social care
The tools are never 100% accurate
Data may be missing from routine databases on certain groups

13. Predictive factors – examples

14. Information flows

15. Data collected From four ‘sites’ (~ PCT areas)
Total seven organisations: 3 PCTs, 1 Care trust, 3 LAs
Total 1.4M pop (range 100, ,000)

16. Data linkage - approach
First instance: NHS number (encrypted) from LA
In absence of NHS number:
Central ‘batch tracing’?
Shared PCT/LA databases?
Ultimately:
construction of ‘alternative IDs’
97% of individuals in one site (population ~400,000) were found to have unique ‘alternative ID’.

17. Data linkage
Groups of people in social care data – how many are we able to match to GP register list (of ages 75+)?
Varies, but better for those with > service use

18. Data linkage Social & secondary care interface

19. Predictive value, sensitivity and specificity of the model incorporating a £5,000 threshold
Predicting social care costs: feasibility study

20. Information on Social Care Needs

21. Simplifying and sorting

22. Individual histories

23. Transitions in care (75+ in one site)

24. Individual health and social care event timeline over a three-year period

25. Predictive Modelling Attempting to predict: For over 75s
Admission to care home (or receipt of high intensity home care) or £5,000 increase in social care costs in one year
Where person had no ‘significant’ costs in prior two years

26. Original models predicting change at £5k threshold

27. Diagram

28. Distillation flask

29. Trade off between PPV (blue line) and sensitivity (red line) according to different risk cut-offs

30. Which variables are important in pooled £1k model?

31. Models using lower £1k thresholds

32. Impact of adding new datasets

33. Iteration with Sites - Application
Several sites said they would like to run the Combined Model and the social care model “side-by-side”
Theographs thought to be very useful
Differences between sites: some sites preferred small numbers of clients others wanted large numbers for mail-shots
Regarded concerns over invasion of privacy as “a non-issue if the wording is right”
Keen to use predictive models for existing or planned re-ablement services and multidisciplinary teams

34. Personal observations on social care data
We could access user level social care data but...
Different systems
Issues of standardisation /coding etc and the absence of standard, structured coding schemes
Some very detailed information collected but can be difficult to use in models
We found it harder to obtain information on descriptions of needs
Local concerns about data quality
Note the history of comparative benchmarking

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36. Headlines
We have created linked health/social care data sets in five sites (overall populations about 2 million people aged 75+)
We modelled intensive social care:
Models had satisfactory PPV but low sensitivity at a risk score threshold of 50 (although can be traded-off against each other)
Mainly social care driven
Though accuracy worse than PARR model, accuracy was comparable with SPARRA and the combined model
Discussion with sites – they were less concerned with model performance than we were
We tried dozens of ways to improve the basic model (5K)
We modelled change in social care costs with lower thresholds: 1K models are much better but usefulness may be diminished

37. And the data have so much more to offer.....
Cost modelling
Iso-resource classification (individual budgets)
Trajectories and transitions of care
Evaluation (re-ablement)
Information for
- Commissioners and managers
Professionals
Service users and carers

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February 2011
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