Usefulness/utility of data on health consumption in Belgian

Health Interview Survey

Dr Johan Van der HeydenScientific Institute of Public Health

Overview presentation

● Background● Domains/indicators● Validity and limitations● Added value compared to other data sources● Linkage with other data

● Which other data?● Objectives● Possible output● Problems

Health Interview Survey Belgium

● Cross sectional (longitudinal part in 2008 ?)● Since 1997● Periodically● Representative sample of population● Household questionnaire – face to face

questionnaire – oral questionnaire● Basic sample = 10.000 persons● Questions on medical consumption besides

other information● Health status: physical, mental, social● Life style● Sociodemographic information

● Use of ambulatory care● Use of institutional care● Use of medicines● Patient satisfaction● Accessibility of health care

Med. consumption in HIS: domains

Use of ambulatory care

● Contacts with GPs – specialists – emergency department● Contacts with dentists

EXAMPLES OF INDICATORS● % population who didn’t visit a health professional < 12 mnths● % population who visited a health professional < 4 wks● Average number of visits to a health professional < 4 wks

Use ambulatory care

● Contacts with paramedics (nurse – physiotherapist – dietician – speech therapist – occupational therapist – psychologist)

● Contacts with practitioners alternative medicine

EXAMPLES OF INDICATORS● % population who visited specific health professionals

(paramedics) < 12 mnths● % population who visited specific categories of alternative

medicine < 12 mnths● % population who used specific care services < 12 mnths

Use of institutional care

● Inpatient hospitalisation● Day patient hospitalisation

EXAMPLES OF INDICATORS● % population who was hospitalized as in-patient < 12 mnths● Average number of in-patient hospitalizations● Average length of stay in a hospital as in-patient● % population who was hospitalized as day patient < 12 mnths● Average number of day-patient hospitalisations

Use of medicines

● Prescribed en not prescribed● Info on medicines used < 14 days: based on

reported information● Info on medicines used < 24 hours: based on

medicines shown to interviewer

EXAMPLES OF INDICATORS● % population that used prescribed medicines < 2 wks● % population that used specific medicine < 24 hrs

● General ● Specific dimensions (GP/specialist)

Patient satisfaction

EXAMPLES OF INDICATORS● % population satisfied with specific health services● % population satisfied with services GP/specialist with respect

to information that is given

Accessibility of care● Health care expenses (ambulatory care, medicines,

institutionalised care, technical aids)● Difficulties to fit health expenses within total budget● Postponement of care for financial reasons (medical care, dental

care, prescribed medicines, glasses, mental health care)

EXAMPLES OF INDICATORS● Absolute and relative expenses for health care● % of population that have difficulties to fit budget for health

care within total budget● % of population that had to postpone health care for financial

reasons

Reported information vs registration

● Memory effects

Memory effects

Number of reported contacts by week, HIS Netherlands, 1981

Reported information vs registration

● Memory effects

● Other problems related to validity:● Info too sensitive● Info too technical

Other validity problems

● E.g. relative expenses for health care● Income

● Correctly reported?● Complete?

● Health expenses● Reimbursement/maximum bill not taken into account

● Case definition (e.g “day patient hospitalisation”)● Sensitive information

For example● Reason for consultation● Why was medicine taken?

Reported information vs registration

● Memory effects

● Other problems related to validity:● Info too sensitive● Info too technical

● Non response/ proxy information

Proxy/non response● Proxy interview

● Overall : 21,7%● Elderly : 13,9%● Elderly in institution : 48,7%

● Unit non response : +/- 40%

● Item non response● E.g.

● Contacts with GP: < 1% to 6.4% ● Income: 26% 12%

Reported information vs registration

● Memory effects

● Other problems related to validity:● Info too sensitive● Info too technical

● Non response/ proxy information

● Other sources of bias

Other sources of bias

● Systematic bias for information that occured in the past● E.g. hospital admissions

● Social desirability● Have you got a regular GP?● Screening practices

Pro

po

rtio

n (

%)

age in 5 year categories

HIS General population (NIS)

0 5- 9 15-19 25-29 35-39 45-49 55-59 65-69 75-79 85 +

0

1

2

3

4

5

6

7

8

Comparison HIS sample - NR

Sample vs exhaustive information

● Lack of precision, especially for:● rare events● subgroups

● Possible bias by chance

Comparison HIS - RIZIV

RIZIV HIS *

Mean number Mean number (+ 95% CI)

All GP contacts 5.48 5.62 (5.20-6.05)

Consultations 2.97 3.53 (3.18-3.89)

Home visits 2.51 2.09 (1.81-2.36)

Mean annual number of contacts with the GP for 1997

* Extrapolation based on contacts in past 2 weeks

Comparison HIS - RIZIV

RIZIV HIS *

Mean number Mean number (+ 95% CI)

Specialist internal medicine 0.26 0.40 (0.31-0.51)

Paediatrician 0.19 0.16 (0.11-0.22)

(Neuro)psychiatrist 0.10 0.12 (0.06-0.17)

All specialists 2.15 2.40 (2.14-2.65)

Mean annual number of contacts with the specialist for 1997

* Extrapolation based on contacts in past 2 weeks

Year HIS* RIZIV

GP 2001 5,25 5,11

2004 4,55 4,74

Specialist 2001 2,29 2,28

2004 2,27 2,34

* Extrapolation based on contacts in past 2 months - people with an independent profession and their dependents excluded

Mean annual number of contacts with the GP/specialist

Comparison HIS - RIZIV

* Extrapolation based on contacts in past 2 months - people with an independent profession and their dependents excluded

Comparison HIS - MKG

MKG HIS *

Mean number Mean number (+ 95% CI)

Men 15.5 14.6 (12.6-16.6)

Women 17.9 18.1 (15.6-20.6)

Total 16.7 16.3 (14.7-18.0)

Number of hospital admissions per 100 persons per year (1997)

* Extrapolation based on contacts in past 2 months - people with an independent profession and their dependents excluded

Comparison HIS - MKG

MKG HIS *

Number of days Number of days (+ 95% CI)

Men 7.8 7.1 (6.0-8.2)

Women 8.5 9.6 (8.1-11.2)

Total 8.1 8.5 (7.5-9.5)

Average duration of a hospital stay (in days) (1997)

0% 5% 10% 15% 20%

infection

male genitals

endocrino

trauma

eye

liver/pancreas

mental

blood

female genitals

skin, breast

urological

ear/nose/throat

neurological

respiratory

digestive

cardiovascular

locomotion

HIS HDD

Reason for hospital admission (HIS 1997)

Comparison HIS - MKG

Added value of HIS

● Horizontal data collection● Study of determinants of consumption

Inequalities in health consumption

Odds ratio (+95% CI)

Model 3Model 2Model 1

6

4

2

1.8.6

.4

.2

Odds ratio (+95% CI)

Model 3Model 2Model 1

6

4

2

1.8.6

.4

.2

GP Specialist

Use of health services in last year by level of education (4 categories)

● Horizontal data collection● Study of determinants of health consumption● Indicators at level of total population

Added value of HIS

● Horizontal data collection● Study of determinants of health consumption● Indicators at the level of the total population● Info on issues for which otherwise no (national)

data

Added value of HIS

● Horizontal data collection● Study of determinants of health consumption● Indicators at the level of the total population● Info on issues for which otherwise no (national)

data● Evolution over time

Added value of HIS

Added value of HIS

● Horizontal data collection● Study of determinants of health consumption● Indicators at the level of the total population● Info on issues for which otherwise no (national)

data● Evolution over time● Microdata easily available

Time trends

Research projects based on HIS

•Statistische analyse van gegevens aangaande gezondheid en de toegang tot gezondheidszorg bij personen van vreemde origine (in vergelijking met totale populatie van een vergelijkbaar project)

•Etude des données contextuelles relatives aux personnes handicapées en région Wallonne

•Socio economic differences in health in Europe

•Le capital social comme facteur de développement

•Is de thuiszorg onderontwikkeld?

•Samenstelling van een wetenschappelijke werkgroep bij de Planningscommissie - Medisch aanbod.

•Actualisation de la partie statistique du rapport sur la cohésion sociale en Region Wallone

•Monitoring van de sociale positie van Vlamingen met functiebeperkingen

Research projects based on HIS

•Berekening gezondheids- en beleidsindicatoren

•Traitement de l'Obésité

•Etude des besoins en soins et en aide des ainés vivant à Bruxelles

•Santé des femmes au travail

•Armoede en sociale uitsluiting jaarboek 2006 - Mentale gezondheid bij allochtonen

•De arbeidsdeelname van mensen met handicap/langdurige gezondheidsproblemen

•Socioeconomic inequalities and use of screeming mammography : results from the Belgiam health interview survey, 2001 and 2004

•Gezondheidsenquête en de 65+ / HS-65

•Qualité de la vie et santé en Belgique

Research projects based on HIS

•L'influence du statut socio-économique de la personne rapportant un trouble dépressif, sur le recours aux soins et la prise en charge par antidepresseurs en Belgique

•Effect van afkomst op gezondheidsgedrag

•Rusthuis/RVT-Bewoners gezondheid en welbevinden

•Differentiatie onder de oudere bevolkingsgroepen? Focus op singles en eenzaamheid.

•International comparisons of health and health determinants

•La qualité de vie des personnes de 65 ans et plus en Belqique : une approche synchronique et diachronique, une analyse des principaux déterminants, des liens avec l'état de santé et de l'existence d'inégalités sociales

•Etude de la santé mentale des personnes refugiées en Belgique

•L'impact du bruit des avions sur le prix des maisons

•Les déterminants du recours aux médecines complémentaires en Belgique

Added value of HIS

● Horizontal data collection● Study of determinants of health consumption● Indicators at the level of the total population● Info on issues for which otherwise no (national)

data● Evolution over time● Microdata easily available● Evolution towards European standardization

Added value of HIS

● Horizontal data collection● Study of determinants of health consumption● Indicators at the level of the total population● Info on issues for which otherwise no (national)

data● Evolution over time● Microdata easily available● Evolution towards European standardization● Possible to link with other data sources

Linkage of HIS data

● Types of linkage● Individual● At aggregated level: household, statistical sector,

municipality

● Objectives● Validation● More in depth exploration of determinants of medical

consumption

● Problems● Practical/technical● Legal/ethical

Precedents/planned initiatives

● 2004: Pilot study on linkage data HIS1997 with RIZIV data (UGent)

● Since 2000: ongoing discussion with privacy commission on follow up study to asses:● validity of sampling methodology (link with NR/census)● link between health and mortality (link with NR)

● 2008 : Data registration oral health (ICE/RIZIV)● 2008 : Multilevel analysis: impact of density

GPs/specialists on volume of contacts

Conclusion

● Main utility of HIS: exploration of determinants of medical consumption

● Useful for national estimates if no other (national) data sources exist

● Linkage with other data feasible but many barriers exist

www.iph.fgov.be/epidemio/epien/index4.htm