1. Salvatore S1 Røislien J2 Baz-Lomba JA3 Bramness JG4
Lisbon Addictions (WWBE) Wednesday, October 25th :00-12:30
Assessing prescription drug abuse using functional principal component analysis (FPCA) of wastewater data.
Salvatore S1
Røislien J2
Baz-Lomba JA3
Bramness JG4
1) Department of Informatics, University of Oslo, Oslo, Norway
2) Department of Health Studies, University of Stavanger, Stavanger, Norway.
3) Norwegian Institute of Water Research, Oslo, Norway
4) Norwegian National Advisory Unit on Concurrent Substance Abuse and Mental Health Disorders

2. Background
The abuse of prescription drugs/medicinal drugs is an increasing problem
Definitely in US
Maybe also in Europe
Monitoring: all data sources have their problems
Reporting/recall bias (illegal, amnesia)
Selection bias (who answers, black market)
Monitoring: could waste water data be an option?
Spatial differences (where are drugs used in excess?)
What could we get out of temporal differences?

3. What's been done in WWBE? Salvatore and Bramness 2015 (unpublished data)

4. Spatial variation (EMCDDA web-site)

5. Temporal variation Zuccato et al 2008
Different drugs are abused differently and behave differently in the sewer
Are there more sophisticated methods for investigating weekend peak?

6. AIM
Can the known weekly temporal variations for drugs of abuse be used to
characterise prescription drugs of abuse?
Methadone
Methylphenidate
Can more advanced statistical methods be used?
Methylphenidate and methadone were chosen because
They were measured
They have less well known black market than e.g. benzodiazepines
They are not metabolically related to other drugs

7. Materials and methods Sewage samples February 2014 Oslo, Norway.
The weekly pattern of each drug
Extracted by fitting of generalized additive models (GAM),
Trigonometric functions to model the cyclic behavior
The weekly component: main temporal features extracted by functional principal component (FPC) analysis
We get FPCs and corresponding FPC scores.

8. MEDICINAL DRUGS OF ABUSE?
Oxazepam
Methadone
Methylphenidate
KNOWN DRUGS OF ABUSE (pos. control)
Methamphetamine
Cocaine (BE)
Heroin (morphine)
Amphetamine
MEDICINAL DRUGS WITHOUT AN ABUSE POTENTIAL (neg. control)
Paracetamol (acetaminophen)
Carbamazepine
Atenolol
Metoprolol
Citalopram (R- and S-)

9. Functional principal components (FPC) Non-normalized data
«Level of drug in WW»
«Height of weekend peak»
«Timing of weekend peak»

11. Findings and conclusion
Letting the data define “weekend” we can extract more information from weekly temporal variations
Methylphenidate, but not methadone seems to have a “weekend peak”
This indicates recreational use of methylphenidate
Published in Pharmacoepidemiology & Drug Safety 2017; 26:

12. Thank you for your attention!
Salvatore S, Røislien J, Baz-Lomba JA, Bramness JG