Registry data from Norway provide valuable information for research.
- Registries allow researchers to describe population health status and health care use. However, registries were not designed for causal inference and say little about disease causes or best treatments.
- Combining registries with cohort studies and biobanks can provide opportunities to identify disease causes and prevention strategies. However, causal inference requires statistical designs that account for confounding factors.
- While Norwegian registries contain useful information, extracting causal insights may be challenging without addressing limitations in registry design and unmeasured confounders. Methodological rigor is needed to bridge the gap between observational data and interventions.
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Why engage with register research?
A short introduction to the different registries
What are the challenges?
‐ Scientific
‐ Bureaucratic
Presentation of national research infrastructures ‐
Health registries for research (HRR)
HRR WP: Biostatistics support
Issues* to consider in registry research
• Norway is famous for our health registries. From a research point of view their
aim is to say something about causality. Why? Because, if you find a causal effect,
then maybe you can intervene and prevent disease or treat people.
• But to which extent is there causal information in the registries? You could have
the most excellent biobank, and it could be virtually useless if data are not
collected according to a statistical design that allows causal inference. Or if there
are numerous unmeasured confounders. Do the registry data really contain a lot
of gold that can be mined?
• Following Judea Pearl's fundamental distinction between seeing and doing:
Registry data are about seeing while the interventions they shall support are about
doing. How to bridge the gap?
• The two pillars of epidemiology are the great data sources, represented by
cohorts, registries and other data collections, and the extensive and deep
methodological thinking.
* Raised by professor Odd Aalen motivating a meeting on causal inference in December 2015
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Another perspective ‐ descriptive
• Epidemiology not only etiologic/causal
research
• Also: describe determinants and health status
of the population
• Global burden of disease project
• Registries underused for such descriptive
purposes
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Global Burden of Disease Study: Levealder – begge kjønn
Norge 2013
81.4 år
15. plass
83.7 år
79.1 år
Data fra Global Burden of Disease Study 2013 – www.healthdata.org
48 50 55 60 65 70 75 80 84
www.healthdata.org
• Global Burden of Disease
(GBD) 1993 prosjekt ved
Verdensbanken og Verdens
helseorganisasjon (WHO)
• WHO perioden 1998‐2003:
World Health Report 2002
• GBD 2010 Studien startet i
2007 ved Institute for Health
Metrics and Evaluation
(IHME) ved University of
Washington i Seattle
• GBD 2013 ‐ første gang for
188 land. Publisert i Lancet
2014‐15.
• GBD 2015 pågår med et
ekspertnettverk på over 1000
forskere fra over 100 land.
• Resultater fra GBD 2013 på
nett: www.healthdata.org
2014‐15
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GBD 2013 – deaths attributable to major risk factors – Norway 2013
Blood Pressure
Diet
Tobacco
BMI
Cholesterol
Fasting glucose
Physical activity
Kidney function
Alcohol/drugs
BMD
Occupation
Other envir
Air pollution
Unsafe sex
Sexual abuse
Malnutrition
WaSH
Cardiovascular disease
Cancer
COPD
Diabetes
GBD 2013 results ‐ http://vizhub.healthdata.org/gbd‐compare/
Data needed on population distribution
of major risk factors;
Confounders/mediators in studies of chronic
diseases and population health
0 2000 4000 6000 8000
www.healthdata.org
• Burden of disease for 195 countries and
terriotories, 1990‐2015
• Deaths, years of life lost (YLL), non‐fatal health
loss (YLD), DALYs (=YLL+YLD)
• and burden (above metrics) attributable to 79
risk factors
• With GBD 2015 soon to be released also
prevalence and incidence
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registries
Electronic nationwide Nordic health registries
with national id‐number
Registry Denmark Finland Norway Sweden
Cause of death 1943 1969 1951 1952
Medical birth 1973 1987 1967 1973
Hospital
discharge
1967 (1977*) 1969 2008 1964 (1987*)
Cancer 1943 1953 1952 1958
Prescription 1995 1994 2004 2005
* Nationwide from the year in parenthesis
From Vollset & Cappelen. Registerepidemiologi. I Laake et al. Epidemiologiske og kliniske
forskningsmetoder. Gyldendal Akademisk 2007 [some corrections made to the original table]
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Some reasons registries are important
• Give overview of the population’s health status and
use of resources in the health care system
• Provide outcomes/events for cohorts and biobanks
• Often RCTs (randomised clinical trials) cannot be used
to advance knowledge
• RCTs rarely done in many medical areas where legal
regulations do not require them (medical devices: eg.
hip/knee‐prostheses, and others)
• Because drug trials do not have sufficient sample size
to detect side effects
Norway Health registries – gold mine?
• There is gold – but it may be hard to find !
• Often gold is made from combining many data
sources
• Sometimes
gold may
be found
within one
register
alone
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Papers in New England Journal of Medicine with first
author from a Norwegian institution 1990‐2015
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014
0.00.51.01.52.02.53.0
3
2
1
Registry based/linkage studies = 13
Randomised clinical trial = 9
Observational clinical study = 2
Basic medical sciences study = 2
Papers in New England Journal of Medicine
with first author from Norway 1990‐2014
• Search in Pub Med: norway[Affiliation] AND n‐engl‐j‐med[Journal]
• 35 hits 1990‐2015 (1 later «retracted», 2 er «sounding board» /
commentary without human data, 6 first author from non‐
Norwegian institution)
• 26 original‐articles remain
– 1 study of NMR for cancer detection, 1 is clinical study of hepC infection in patients receiving
immunglobuliner, 1 er en studie av assay for troponin T i et materiale fra en randomisert
studie blant hjertekar‐pasienter, 1 is description of novel dominant genetic disease
– 9 are randomised clinical trials, (7 in cardiovascular area)
– 13 of 26 articles are based on Medical birth registry, Cancer
registry, Cause of death registry or other data sources (cohorts,
biobanks) linked to these registries for outcome measures
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On causal information
• None of the registries we are famous for were
designed for causal inference, neither for
etiological nor for identifying best treatments
• They are event registries and say little about
causes of the event or factors that may improve
the outcome after the event (treatment)
• However, many clinical quality registries are
designed for causal inference (identify best
treatment), as are cohort studies and biobanks
linked to cohorts (identify causes of disease,
prevention opportunities)
Typology of Health Registry data
1. (see) Health care system or population events
2. (see) Population risk factors (etiologic factors;
behavioral, metabolic, environmental/occupational),
population gene data
3. (see) Clinical information: diagnosis with prognostic
factors, severity of disease, functional level associated
with a disease, stage of disease, genetic/metabolic
disease markers. Repeated information over time.
4. (do‐factors) Treatments, interventions, preventive
measures, screening programs, risk factors
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Registry, cohort/biobank information
(see) Health care system or population events
Nation‐wide population‐based mandatory registries (14)
• Cause of death registry
• Cancer registry
• Population registry
• Medical Birth Registry
• Prescription registry
• Patient registry
• Cardiovascular disease registry
• Vaccination registry
• Infectious disease registries
• Primary care data [all contacts] – not registry status yet
• Unsystematic and sparse information on risk factors,
prognostic factors, treatments (dose, duration, surgery,
devices), functional status.
• Limited use for causal inference alone
(see/do) COHORTS/BIOBANKS
Population risk factors
(etiologic factors; behavioral,
metabolic, environmental
/occupational), population gene
data
Mother &Child Cohort
Cardiovascular Screening Programs
JANUS Biobank
Tromsø and HUNT cohorts
Gain value with follow‐up
Loss of value without regular
updating of exposure and
confounder information
need regular updating(see) Clinical quality registries
(58 with national status)
Clinical information: diagnosis with
prognostic factors, severity of
disease, functional level associated
with a disease, stage of disease,
genetic/metabolic disease markers
(do‐factors) Treatments,
interventions, preventive
measures, screening
programs, risk factors
Need great detail, many events with
duration, dose, type of intervention
and intermediate results
May be found in good Clinical quality
i
Sentrale/lovhjemlede
helseregistre
› Lovhjemmel i helseregisterloven - juridisk definisjon
› Etablert av den sentrale helseforvaltningen
› Landsdekkende – Meldeplikt
› Registerformer
› Anonyme/avidentifiserte
› Pseudonyme
› Personidentifiserbare
› Samtykke
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Sentrale/lovhjemlede helseregistre
1. Dødsårsaksregisteret
2. Medisinsk fødselsregister
3. Hjerte- og karregisteret
4. Meldingssystem for smittsomme sykdommer (MSIS)
5. Nasjonalt vaksinasjonsregister
6. Resistensregistrene (NORM, RAVN)
7. Norsk overvåkingssystem for infeksjoner i sykehustjenesten (NOIS)
8. Reseptbasert legemiddelregister
9. Register over svangerskapsavbrudd
10. Kreftregisteret
11. Genetisk masseundersøkelse av nyfødte
12. Norsk pasientregister
13. Informasjonssystem for pleie og omsorgssektoren (IPLOS)
14. Forsvarets helseregister
Under etablering
1. Helsearkivregisteret
2. System for bivirkningsrapportering
Sentrale helseregistre per februar 2015
Register Etablert Owner/
ID
1. Dødsårsaksregisteret / Cause of death Registry 1925 FHI Pid.
2. Medisinsk fødselsregister / Medical Birth Registry 1967 FHI Pid.
3. Register for svangerskapsavbrudd / Registry for abortions 1979 FHI deid.
4. Nasjonalt register over hjerte‐ og karlidelser / Cardiovascular disease registry 2012 FHI Pid.
5. Meldingssystem for smittsomme sykdommer (MSIS) / Surveillance system infectious diseases 1977 FHI Pid/deid
6. Nasjonalt vaksinasjonsregister (SYSVAK) / Vaccination registry 1995 FHI Pid.
7. Resistensregistrene (NORM, RAVN) / Registries for antibiotic resistance 2000 FHI deid.
8. Norsk overvåkingssystem for infeksjoner i sykehustjenesten (NOIS) / Hospital infections registry 2005 FHI deid.
9. Reseptbasert legemiddelregister / Prescription registry 2004 FHI Pseudo
10. Kreftregisteret / Cancer Registry 1951 Kreftregisteret Pid.
11. Norsk pasientregister (NPR) / Patient registry (hospitalisations and outpatient visits) 1997/2008Helsedir. Pid.
12. IPLOS‐registeret 2006 Helsedir. Pseudo
13. Forsvarets helseregister / Norwegian defence health registry 2005 Forsvarsdep. Pid.
14. Genetisk masseundersøkelse av nyfødte / Genetic mass‐screening of newborns 2012 OUS Pid.
https://ehelse.no/helseregistre
National health registries 2015
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› Helse Nord RHF
› Nordisk register for hidradenitis suppurativa - HISREG
› Norsk Nakke- og Ryggregister
› Nasjonalt kvalitetsregister for ryggkirurgi
› Norsk register for arvelige og medfødte nevromuskulære
› sykdommer
› Norsk register for analinkontinens
› Norsk Register for Gastrokirurgi - NoRGast
› Norsk kvalitetsregister for behandling av spiseforstyrrelser
› - NORSPIS
› Helse Vest RHF
› Norsk kvalitetsregister for artrittsykdommer (NorArtritt)
› Det Norske Nyrebiopsiregisteret
› Nasjonalt register for organspesifikke autoimmune sykdommer
› (ROAS)
› Nasjonalt register for langtids mekanisk ventilasjon (LTMV)
Nasjonalt register for invasiv kardiologi
Nasjonalt register for ablasjonsbehandling og elektrofysiologi
› Norsk porfyriregister
› Norsk MS Register og biobank
› Nasjonalt korsbåndregister
› Nasjonalt hoftebruddregister
› Nasjonalt Barnehofteregister
› Nasjonalt register for leddproteser
› Nasjonalt register for kronisk obstruktiv lungesykdom (KOLS)
› Norsk kvalitetsregister for leppe- kjeve- ganespalte
› Norsk Intensivregister (NIR)
› Norsk diabetesregister for voksne
› Norsk kvalitetsregister for fedmekirurgi
› Nasjonalt Kvalitetsregister for Smertebehandling 27
52 nasjonale medisinske kvalitetsregistre (2015)
› Helse Midt RHF
› Norsk ryggmargsskaderegister - NorSCIR
Norsk hjertesviktregister
Norsk hjerneslagregister
Norsk Karkirurgisk register - NORKAR
Norsk hjerteinfarktregister
› Helse Sør-Øst RHF
Nasjonalt register for brystkreft
Nasjonalt register for føflekkreft
Nasjonalt register for barnekreft
Nasjonalt register for gynekologisk kreft
Nasjonalt register for malignt lymfom og kronisk lymfatisk
leukemi
Nasjonalt register for lungekreft
Nasjonalt register for prostatakreft (NPPC)
Nasjonalt register for tykk- og endetarmskreft
› Norsk kvinnelig inkontinensregister (NKIR)
› Kvalitetsregister for demens
Nasjonalt hjertestansregister
Norsk Pacemaker og ICD-register
› Norsk kvalitetsregister for hiv (NORHIV)
› Norsk gynekologisk endoskopiregister (NGER)
› Norsk Nefrologiregister
Det norske hjertekirurgiregisteret
› Gastronet
› Nasjonalt kvalitetsregister for døvblindhet
› Nasjonalt traumeregister
› Cerebral pareseregisteret i Norge (CPRN)
› Norsk Nyfødtmedisinsk Kvalitetsregister (NNK)
› Nasjonalt medisinsk kvalitetsregister for barne- og
› ungdomsdiabetes
Andre datasamlinger
› Fagsystemet KUHR
(Kontroll og utbetaling av helserefusjoner, HELFO) -
Primærhelsetjenesten
› Forløpsdatabasen trygd (FD-trygd, SSB)
› Sosioøkonomiske og økonomiske individdata i SSB
(inntekt, utdanning, sysselsetting, fødeland m.m.)
› Folkeregisteret (Skatteetaten)
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Norwegian arthroplasty register
• Hip replacement registry
• Treatment registry – type of hip prosthesis
• Narrow range of diagnoses: Osteoarthritis
• Follow‐up till failure (reoperation prosthesis)
• Norway register from 1987
• 164 000 primary hip prostheses followed
• 27 000 reoperations with replacements
• In 2014 more than 40 treatment combinations
(semented, uncemented, hybrid, different brands
and designs) – 17 cement types
Journal Bone Joint Surg Br 1995
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Journal Bone Joint Surg Br 1995
Why does the arthroplasty registers work
[i.e. give good guidance to selecting best treatment]
• Very heterogenous treatment options, hundreds of
brands/types, brand/type combinations, cements in use
over time
• Relatively homogeneous patient group (moderate variation
in prognosis)
• Little clinical knowledge or clinical beliefs of choice of
treatment options according to prognosis of the patient
• Therefore clinical reality approximately allocates
treatments unrelated to prognosis (except may be age, that
is easily controlled for)
• Treatment choice is often made at the institutional level
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Questions that registry data can answer
[alone or in combination with other data sources]
• Trends in still births, perinatal and infant mortality
• Trends in maternal/gestational diabetes
• Trends in use of cesarean sections
• Which drugs cause congenital malformations
• Long term prognosis of low‐birth weight/prematurity
• Is assisted reproductive technology safe ?
• Sleeping position and sudden infant death syndrome
vollset ‐ health registries in norway ‐ isar – bergen – 20‐22 May 2012 slide 34
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Research question
How will prematurely born manage
the competitive adult society?
Is it possible to design a study
answering this question, including all
gestational ages and not only the
most immature?
Moster et al. New Engl J Med 2008
vollset ‐ health registries in norway ‐ isar – bergen – 20‐22 May 2012 slide 35
9 Norwegian registries that provided outcomes
for the study
• The Medical Birth Registry
• The Cause of Death Register
• The National Insurance Scheme (disabilities, ICD codes)
• The Norwegian Population Database (demography)
• The National Education Database (education, mother and
father; proxy for social class)
• The Norwegian Tax Administration’s register (income)
• The National Employment Service’s register (employment
status)
• The Register of Social Services (social benefits)
• The Central Criminal and Police Information Register
Moster et al. New Engl J Med 2008
vollset ‐ health registries in norway ‐ isar – bergen – 20‐22 May 2012 slide 36
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• Year of birth 1967‐1983
• 903,402 livebirths without congenital anomalies
1 822 born at 23 to 27 weeks of gestation
2 805 at 28 to 30 weeks
7 424 at 31 to 33 weeks
32 945 at 34 to 36 weeks
858 406 at 37 weeks or later
• Follow‐up through 2003 (34 years of data collection)
The Medical Birth Registry
– Selection of study population
Moster et al. New Engl J Med 2008
vollset ‐ health registries in norway ‐ isar – bergen – 20‐22 May 2012 slide 37
Conclusion:
• There was a highly significant association between
reduced gestational age at birth and medical
disabilities (e.g. cerebral palsy or mental retardation)
• For those without disabilities, there was a weaker, but
still significant association between preterm birth and
level of education, income, need for social security
benefits, establishing a family and having own
children, but not for unemployment or criminality.
• There was a striking dose-response relationship
between reduced gestational age and most outcomes
studied.
• Most premature children who survived without medical
disabilities functioned well as adults.
Moster et al. New Engl J Med 2008
vollset ‐ health registries in norway ‐ isar – bergen – 20‐22 May 2012 slide 38
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Factors considered: birth weight,
gestational age, growth retardation,
perinatal mortality in 2546 women who
had conceived both naturally and by assisted fertilisation
The Lancet 2008
Question: Does
assisted fertilisation
harm the baby ?
Key idea:
compare pregnancy
outcomes in women
who had singleton
pregnancies
conceived both
spontaneously and
after assisted
fertilisation
2546 such women
identified in Medical
Birth Registry
Irgens LM, Markestad T, Baste V,
Schreuder P, Skjærven R, Øyen N.
Sleeping position and sudden infant
death syndrome in Norway 1967‐91.
Arch Dis Child 1995;72:478‐82.
Sudden infant death syndrome (SIDS) and sleeping position
Data:
• Time trend in SIDS from Medical
Birth Registry
• Exposure from ad hoc survey in
1992
• Time trend in retrospectively
reported sleeping position i 1992
for the years 1970, 75, 80, 85, 89,
90, 91 by 24438 mothers (70%
response rate) sampled from 20
largest maternity institutions.
• For each year and institution 250
mothers were randomly selected
7x20x250=35000
• One page questionnaire
• 92.5% stated the were certain
about the babies sleeping position
at 3 months of age
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Population Registry of Norway
Surveillance System of Infectious
Diseases
(MSIS)
•Positive H1N1 tests
Medical Birth Registry of Norway (MBRN)
•Pregnancy outcomes
•Chronic conditions in pregnant women
Immunzation Registry
(SYSVAK)
•Vaccination status
•Date of vaksination
43
HELFO‐data
Reimbursement of doctors
(KUHR )
•Primary care consultations
•Influensa (R80)
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Conclusion
• The natiowide population‐based (central) registries we are famous for
(Cancer registry, Medical birth registry, Cause of death registry,
Prescription registry, Patient registry and others) are not designed to
contain causal information
• Quality registries, cohorts, biobanks associated with cohorts are designed
to study causes of diseases and to identify best treatments
• We need to establish data collection that can enrich the central registries
(determinants of population health, diet, smoking, blood pressure,
cholesterol, BMI, alcohol/drugs, occupational exposure, environmental
exposure and others). These factors are also often prognostic factors
• Regular updates is needed and best done in large representative cohorts
or dedicated risk factor data collection systems
• Case‐control design is sometimes used in registry data collection to
provide population data on risk factors (for each event – identify 1 or more
similar persons from population)
Conclusion (cont.)
• Without large cohorts and biobanks the central registries
are of limited value for causal analysis
• Clinical Quality registries have a great potential for analysis
of treatments and prognostic factors. They need to be
adequately sized, have sufficient follow‐up time and
detailed information both on treatment (type, dose,
duration, detailed information on procedures and devices)
and general risk factors / prognostic factors.
• Information on national risk factor distributions are
necessary to compute population attributable numbers
from universal RR estimates and observed event numbers
in the population.
• In short, we lack a risk factor registry (e.g. large living
national cohort, or system for regular risk factor data
collection)