1. Depression and work incapacity in Scotland: Evidence from the Scottish Health and British Household Panel Surveys Matt Sutton Will Whittaker Health Methodology Research Group (matt.sutton@manchester.ac.uk)

2. Background Part of a mixed-methods research project funded by the Chief Scientist Office of the Scottish Government Health Directorate General Research questions for survey analysis –Who is likely to transit to and from Incapacity Benefit? –Can the at-risk individuals be identified in general practice? –Do practices influence work incapacity?

3. Trends in Incapacity Benefit receipts - UK

4. Trends in mental health - BHPS

5. Trends in mental health of IB recipients

6. Who is likely to transit to and from Incapacity Benefit?

7. British Household Panel Survey Longitudinal sample, with refreshment and booster samples 17 waves of interviews (1991 – 2007) Interviews in autumn –Current status –Experience since 1 st September of previous year Analysis of working-age population with interviews in consecutive years Analysed years of exposure: –32,130 inactive job status –114,092 active job status –7,964 on Incapacity Benefit

8. Analysis Probability of transit: –From inactive job status to IB –From active job status to IB –Off of IB Multivariate logistic regression with random-effects for individuals Explanatory variables: –GHQ-12 score; Other health problems; Year; Ethnicity; Educational attainment; UK region; Marital status; Age; Gender; Children –Inactive status –Standard Occupational Classification; Employment sector

9. Conditional influence of mental health on transits

10. Conditional influence of other health conditions on transits

11. Conditional regional variations in transits

12. Conditional trends in transits onto IB

13. Conditional regional variations in transits onto IB

14. Can the at-risk individuals be identified in general practice?

15. Identifying those at risk Identify starting year of first spell of Incapacity Benefit claiming –N = 1,758 first spells Calculate prevalence in preceding and proceeding years of: –GHQ Caseness –Frequent GP attendance (10+ per annum)

16. Mental health by spell period

17. Frequent GP attendance by spell period

18. Do practices influence work incapacity?

19. Scottish Health Surveys Cross-sectional surveys in 1995, 1998 & 2003 Subsequently linked to NHS administrative records, including registered general practice at time of survey We analyse the working-age population, excluding early retired Sample = 12,221 individuals registered with 948 general practices

20. Analysis Multivariate logistic regression with random-effects for practices Empty model and model with explanatory variables: –Year –Gender –Age category –Marital status –Educational achievement –Health region –Area deprivation quintile Focus on proportion (and significance) of unexplained variance at practice level (rho)

21. Amount of practice variation

22. Comparator variables Female Married and living with spouse Longstanding illness - mental condition GHQ Caseness GP visit in last fortnight Less than degree (or equivalent) educational attainment

23. Amount of practice variation

24. Summary of findings Increasing proportion of work incapacity attributable to mental health Mental health significantly influences the probability of transition to and from IB – robust to other influences Factors influencing the probability of transition to IB are similar for individuals with depression to those for the entire population Increasing prevalence of GHQ Caseness in years leading up to start of IB spell – though frequent GP attendance increases more distinctly Significant practice variation in prevalence of work incapacity..but this may reflect geographical concentrations of socioeconomic factors rather than variations in practice behaviour