1. Unit of EPIDEMIOLOGY SCIENTIFIC INSTITUTE OF PUBLIC HEALTH Comparison of HLY from different health surveys 4th Meeting of the Task Force on Health Expectancies Luxembourg, 4 th June 2007 Bianca Cox

2. Introduction ●EHEMU Information System : Health expectancies for 25 European countries ● Demographic data Eurostat + national statistical centers ● Health data Eurostat, DG SANCO, Mannheim University  from different European surveys

3. Introduction

4. ●Are the health expectancies for a given country comparable between the surveys? ●Surveys carried out in the same year (2004): ESS, SHARE, SILC  Common health indicators : ● Self-Percieved Health (SPH) ● Activity Limitation (AL)

5. Data ●Health expectancies comparison WITHIN country : same demographic data ●Raw health data (prevalences) ● Self-Percieved Health : good, fair, bad ● Activity Limitation : without, moderate, severe  Average over 5-year age groups: 50-54, 55-59,…, 85+

6. Analyses ●Health expectancies : graphical exploration ●Prevalences : logistic regression  Separate model for each health state and gender ● Overall models : ● Main effects : survey, agegr, country ● Interactions : survey*agegr, survey*country, agegr*country ● Country-specific models : ● Main effects : survey, agegr ● Interactions : survey*agegr  Odds ratio estimates of one survey vs the other for agegroups 50, 65 and 85+

7. Results : Graphical exploration SPH health expectancies

8. Results : Graphical exploration AL health expectancies

9. Results : Graphical exploration health expectancies ●Common trend in some countries : ● Self-Perceived Health : ● Good : SHARE > ESS > SILC ● Bad : SHARE < ESS < SILC ● Activity Limitation : ● Without : ESS > SILC > SHARE ● Severe : ESS < SHARE < SILC ●Confidence intervals of health expectancies : SILC << SHARE < ESS

10. ●Overall models : ● Survey*agegr, survey*country, agegr*country ● SPH: sign. in all 6 models ● AL: sign. in 4 models (not in ♀ models for “without” & “severe”) ●  Effect of survey different for different age groups and countries ●Country-specific models : ● Odds ratio estimates of one survey vs the other for age groups 50, 65 and 85+ Results : Logistic models on prevalences

11. Results : Logistic models on SPH prevalences + or -odds ratio > 1 or odds ratio < 1 A & Bnumber of models with a significant odds ratio Cnumber of models with a odds ratio > 1

12. Results : Distribution of odds ratio estimates for SPH Good SPH males Good SPH females Bad SPH malesBad SPH females SH > ES > SI SH (<) ES < SI

13. Results : Logistic models on AL prevalences + or -odds ratio > 1or odds ratio < 1 A & Bnumber of models with a significant odds ratio Cnumber of models with a odds ratio > 1

14. Results : Distribution of odds ratio estimates for AL Without AL malesWithout AL females Severe AL malesSevere AL females ES > SI > SH ES < SH < SI

15. Discussion ●Significant effect of survey, different for different age groups and countries ●Still : odds ratios show common trend across age groups and countries ● Good SPH : SH > ES > SI ● Bad SPH : SH (<) ES < SI ● Without AL : ES > SI > SH ● Severe AL : ES < SH < SI ●Significance of odds ratios increases with age but also the variability in the distribution of the odds ratio estimates  chance effects due to smaller sample sizes

16. Discussion ●Possible reasons for differences between surveys : ● Different sampling designs : Sr = Simple random sampling Systrs = Systematic random sampling Stratrs = Stratified random sampling Ms = Multi-stage sampling Final sampling units: P = Persons H = Households A = Addresses T = Telephone numbers D = Dwellings But : Sampling design depends more on country than on survey  Survey design often constrained by what is available in the country

17. Discussion ●Possible reasons for differences between surveys : ● Different selection bias : e.g. participation / item response ● Different sample sizes : SILC > SHARE > ESS ● Different position in questionnaire ● Differences in wording: ● SPH : “ How is your health in general ? ” ESS & SILC general questionnaires : “health” further specified (f.e. including mental health) in footnote or between brackets  Also in country-specific questionnaires or spoken out by interviewer ??

18. Discussion ● AL : - ESS : “ Are you hampered in your daily activities in any way by any longstanding illness, or disability, infirmity or mental health problem ? ” - SHARE & SILC : “ For the past six months at least, to what extent have you been limited because of a health problem in activities people usually do ? ”