1. Workshop From petri dish to population - and back again
Chairman: Anne Broe, Danish Society for Pharmacoepidemiology
DSF Annual meeting

2. 15.00-16.15 From petri dish to population - and back

3. Options and possibilities with Danish register research – On its own or as a supplement
Dansk Selskab for FarmakoEpidemiologi

4. Pharmacoepidemiology
Pharmacology – the study of medicines and drugs, including their action, use, and effect on the body
Epidemiology – the scientific study of disease and how they are found, spread, and controlled in groups of people
The study of drugs on a population level

5. Pharmacoepi studies Observational studies
Limitations of drug safety data from clinical trials
Increased focus on pharmacovigilance
Target population for medicines
Safety endpoints (post-authorization)
Pitfalls
Random variation
Systematic error (bias)
Selection bias
Information bias
Confounding
Billedet er lånt fra Jesper

6. Pharmacovigilance (‘drug watch’/drug safety)
Monitoring the safety of drugs after authorization
Adverse drug effects (noxious and unintended)
Medication errors (overdose, misuse, abuse)
Collection,
Detection,
Assessment,
Understanding,
and prevention of adverse effects

7. FALSE ADVERSE EFFECTS Tak til Jesper for humoristisk slide 

8. Thalidomide

9. Advantages
Incidence rates Prevalence proportion Use of single substances Persistence (‘drug survival’) Co-medication Prescriber types Regional differences

10. Confounding Users and non-users are not comparable
Confounding by indication/disease severity
Methods to control for confounding
Design Analysis
Randomization Stratification
Cross-over Multivariate analysis
Restrictions Propensity score (PS)
Matching Self-controlled studies

11. Evidence Hierarchy

12. Limitations of clinical trials
Short follow-up
Selected study populations
Off label use
Random outcome in small trials (but no confounding in big trials)
Billedet er lånt fra Jesper

13. Conclusion Clinical trials are not suitable for long term follow-up
Does not reflect real-life patients (only the selected study group)

14. Danish data – so what?

15. Danish data are pretty unique!
Long register lifetime
Population based
Government funded health care
High coverage and validity

16. MEDSTAT.DK
   

17. Medstat.dk
Freely available source of aggregated prescription drug statistics
Annual national aggregated sales data
Cannot describe level of individual exposure
Covers ALL sales including in hospital treatments and over the counter sales

19. Drug utilization How much drug X is used per Danish citizen?
Among women?
In the reproductive age?
Are there differences between regions?
Estimates can be generated from aggregated sales data
Historic trend in sale
Comparison with other countries

22. Adelborg K et al. Sixteen-year nationwide trends in antithrombotic drug use in Denmark and its correlation with landmark studies. Heart (2016)
Heart impact factor 5

23. Nonaspirin Nonsteroidal Antiinflammatory Drug Use in the Nordic Countries from a Cardiovascular Risk Perspective, 2000–2016: A Drug Utilization Study
Kasper Bruun Kristensen, Øystein Karlstad, Jaana E. Martikainen, Anton Pottegård, Jonas W. Wastesson, Helga Zoega & Morten Schmidt

24. n=
The nordic countries consist of Iceland, Norway, Sweden, Finland and Denmark.
Although relatively smalle individually, the importance of the nordic countries as a group is considerable. In total 27 million inhabitants, and the domestic product combined makes it the worlds 12th largest economy. In our nordic countries we share a common history and we do have other features that are characteristic, that is our welfare systems. We have practically universal health care to all residents and health care registries of good quality and coverage.
Even though we are alike, there are differences so it may be a good idea to pair up with collaborators who know each country. As you may be able to see from the names of people involved in this work all countries are represented and I found this really useful.
These are the countries we studied and we studied the use of NSAIDs

26. Individual level data Statistics Denmark (DST)
Danish Health Data Authority (SDS)
Unique Person Identification (CPR)
- National Patient Registry
- National Prescription Registry
- Medical Birth Registry
- Cancer Registry
- Registry of Cause of Death
Schmidt et al. Eur J Epidemiol 2014