Genetics and Insurance: An Actuary's View
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Transcript Genetics and Insurance: An Actuary's View
The Economic Stakes Involved in
Genetic Testing for Insurance
Companies
Angus Macdonald
Heriot-Watt University, Edinburgh
and the Maxwell Institute for Mathematical Sciences
Outline
Fundamental
questions
Problems posed by genetic testing
Seeking evidence from data
Examples
Conclusions
Same Premiums or Not?
Motor
Insurance
– 40-year old, no accidents, family car
– 17-year old, no experience, sports car
Same Premiums or Not?
Life
Insurance
– Man, 40, smoker
– Man, 40, non-smoker
Same Premiums or Not?
Pension
– Man, age 65
– Woman, age 65
Same Premiums or Not?
Life
Insurance
– Man, 30, father had Huntington’s disease
– Man, 30, no family history of Huntington’s
Same Premiums or Not?
Life
Insurance
– Woman, 30, tested and has BRCA1 mutation
– Woman, 30, never tested
Mathematical Basis of Insurance
All
these examples rest on the same
principles
Insurance has a mathematical basis
– Imperfect, fuzzy
– Judgement not excluded
Arbitrary
pricing MAY, SOMETIMES,
damage the system
Who Actually Buys Insurance?
50%
50%
Combined
60%
Group 1
Group 2
“Long Lived”
“Die Young”
£1,000
£2,000
40%
£1,500
Who Actually Buys Insurance?
50%
50%
Combined
60%
Group 1
Group 2
“Long Lived”
“Die Young”
£1,000
£2,000
40%
£1,600
Two Kinds of Adverse Selection
Insurers
gaming against each other
– Smoker/Non-Smoker differentials
– Male/female differentials (?)
Applicants
not disclosing information
– AIDS (USA)
– Mortgage life insurance (UK)
– Genetic information (?)
Pooling of Risk
50%
50%
Combined
Group 1
Group 2
“Long Lived”
“Die Young”
£1,000
£2,000
£1,500
Two Basic Economic Questions
If
insurers do have genetic information:
– People at higher risk might pay more
– Question: how much more?
If
insurers do not have genetic information:
– People at higher risk might over-insure
(adverse selection)
– Question: how much would that cost?
Single-Gene Disorders
Gene
Disease
Single Gene Disorders
Can
present high risk of disease/death
Can have late onset
Treatment drastic or non-existent
Rare
Known about - epidemiology exists
Can present clear pattern in family history
Family history risk already underwritten
Very High Risk
Probability of serious illness by age 60:
Average:
15%
APKD1 mutation carrier:
75%
Huntington’s mutation carrier: 100%
Multifactorial Disorders
Smoking
Gene 2
Gene 1
Affluence
Disease
Diet
Gene 4
Gene 3
Gene 6
Gene 5
Multifactorial Disorders
Common
diseases (cancer, heart disease)
Complex interactions
– Many variants of many genes
– Environment
Altered
susceptibility, not very high risk
Pattern of inheritance unclear
Not much epidemiology (yet)
Genetic Tests: How Predictive?
Single-gene disorders: STRONGLY
Multifactorial disorders: WEAKLY
An Example of Evidence: APKD
Adult
Polycystic Kidney Disease (APKD)
Leads to kidney failure and transplant
APKD1
– Causes ~ 85% of APKD
APKD2
– Causes ~ 15% of APKD
Epidemiology
exists
CI Extra Premiums (Males)
Gene
Age 30 Age 30 Age 30 Age 40
Term 10 Term 20 Term 30 Term 10
APKD1
APKD2
492%
108%
639%
101%
521%
99%
775%
100%
(FH)
214%
267%
209%
305%
Adverse Selection Costs (CI)
Premium
increases to cover cost
Under extreme assumptions:
– Ban on all test results
– Ban on adverse test results
– Ban on family history
(1) Cost of broader risk pool
(2) Cost of adverse selection
(Males)
0.44%
0.32%
0.35%
1.25%
Life Ins Extra Premiums (Males)
No Transplants, Dialysis Only
Gene
Age 30 Age 30 Age 30 Age 40
Term 10 Term 20 Term 30 Term 10
APKD1
APKD2
73%
17%
132%
28%
146%
31%
93%
16%
(FH)
32%
57%
62%
37%
Life Ins Extra Premiums (Males)
Immediate Transplantation
Gene
Age 30 Age 30 Age 30 Age 40
Term 10 Term 20 Term 30 Term 10
APKD1
APKD2
12%
3%
44%
9%
53%
11%
19%
3%
(FH)
5%
19%
23%
8%
CI Extra Premiums (Males)
Gene
Age 30 Age 30 Age 30 Age 40
Term 10 Term 20 Term 30 Term 10
APKD1
APKD2
492%
108%
639%
101%
521%
99%
775%
100%
(FH)
214%
267%
209%
305%
Challenges to Family History
Heterogeneity
means that an adverse test is
not always worse that family history
If family history is uninsurable, is there an
implied requirement to be tested?
If treatment normalizes risk, is there an
implied requirement to be treated?
Genetics of Tomorrow
Genetics
of common diseases
Gene-gene, gene-environment interactions
Whole-genome scans, genetic arrays
Large-scale population studies
Novel mechanisms (epigenetics, RNA
interference)
Genetic therapy
Insurance Implications
High-throughput genetic arrays will reveal much
about complex genetic influences on biological
processes – but this is not the same as disease.
Understanding biological processes better will
help to understand disease – but this is not the
same as epidemiology.
Epidemiology will emerge:
– But it will not be highly predictive, as for single-gene
disorders
– For insurance purposes it might fail criteria like
“reliability”.
Why Are Genes Special?
Probability
of dying before age 60?
Mr Smith and Mr Brown
– One is a mutation carrier:
20%
– One has had a serious illness: 20%
If
you did not know which of Smith or
Brown had a mutation, who would get
special treatment?
The Economic Stakes Involved in
Genetic Testing for Insurance
Companies
Angus Macdonald
Heriot-Watt University, Edinburgh
and the Maxwell Institute for Mathematical Sciences