the 2002 healthcare conference 29 september-1 october 2002 scarman house, the university of warwick,...

The 2002 Healthcare Conference

29 September-1 October 2002

Scarman House, The University of Warwick, Coventry

Session B1 : Critical Illness

Trends in Critical Illness

Heart Attack & Stroke

Working Party / Research Sub-group Report

Scott Reid & Joanne Wells

Critical Illness Trends Working Party

Our Aims : To examine underlying trends in the factors influencing UK

Insured Critical Illness claim rates, and from these, to assess : The historic trend in incidence and death rates for the major CI’s Any pointers for future trends in Standalone CI, Mortality and hence

Accelerated CI.

Formed in March 2001

Sub-Group Members

Actuaries

Scott Reid

Joanne Wells

Medical Expert

Dr Richard Croxson - Consultant Cardiologist

Contents Slide

Background and set the scene Variations by deprivation category Variations by ICD code Impact of smoking Future influences on rates Project population incidence rates

Background and set the scene

Re-cap of previous work Data sources used

Scottish English

Next step forward

Re-cap of previous work

Population trends – Scotland and England Heart attack Stroke CABG Angioplasty

Broad brush analysis of smoker prevalence

Population trends – Scotland and England

Heart attack Significant mortality and incidence improvements Scottish rates at a significantly higher level

Stroke English data unclear Scottish data

Flat trend during 1980’s Deterioration during early 1990’s

Broad brush analysis of smoker prevalence

Smoking is a key risk factor Reduction in smoking prevalence Scottish and English smoker prevalence patterns

Scottish trends


Re-cap of previous work Data sources used

Scottish English

Next step forward

Data sources used

Scottish population – ISD data Good quality Patient based

English population - HES data Data quality is questionable Episode based


Next step Insured trends Understanding the main drivers to cause trends Smoker differentiated rates Future influences Overall trend pattern

Contents Slide


Variations by deprivation class

Why split by deprivation class? Data sources used Explanation of deprivation scores and categories Overall trends by gender

Heart attack Stroke

Conclusion

Why split by deprivation class?

To understand trend at insured level Regional variations and Target market variations Understand the main drivers of health inequalities

Black report 1980: “..the main influence on the inequalities in health which were observed lay in the material circumstances in which people live”

Deprivation and Health in Scotland, 1991 (Carstairs & Morris) Classification by postcode; overcomes the weakness of

Occupational classification.



Heart attack Stroke

Conclusion

Data sources used

Incidence data SMR1/01, Information Statistics Division NHS Scotland General Registers Office for Scotland

Mortality data General Registers Office for Scotland

Population data 1981 Population Census 1991 Population Census

Split by CI condition ICD code Gender 5 year age bands deprivation category



Heart attack Stroke

Conclusion

Explanation of deprivation scores and categories

Carstairs & Morris 1991 deprivation categories Four indicators – to derive a composite score

Overcrowding Male unemployment Low social class No car

Deprivation score divided into 7 separate categories 1 – the most affluent group …… 7 – the most deprived group

Explanation of deprivation scores and categories

Population living at different levels of depreviation: England, Wales and Scotland

Scotland England and Wales% Population % Population

Deprivation 1991 census 1991 censusCategory

1 6% 21%2 14% 30%3 22% 22%4 25% 15%5 15% 7%6 11% 4%7 7% 1%

100% 100%



Heart attack Stroke

Conclusion

Trends in incidence of first heart attack for males in Scotland, as a % of 1981 Value, 1981 to 2000

40%

50%

60%

70%

80%

90%

100%

110%

120%

1981 1983 1985 1987 1989 1991 1993 1995 1997 1999

0-39 40-64 65+


40%

50%

60%

70%

80%

90%

100%

110%

120%

1981 1983 1985 1987 1989 1991 1993 1995 1997 1999

40-64


40%

50%

60%

70%

80%

90%

100%

110%

120%

1981 1983 1985 1987 1989 1991 1993 1995 1997 1999

1 2 3 4 5 6 7 overall

Trends in incidence of first heart attack for males in Scotland, per 100000 of population, 1981 to 2000

0

200

400

600

800

1000

1200

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

1 2 3 4 5 6 7 9

Trends in incidence rate of first heart attack for males aged 40 to 64 in Scotland, per 100000 of Population, 1981 to 2000

0

200

400

600

800

1000

1200

1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

Insured Population best worst

Trends in incidence rate of first heart attack for males aged 40 to 64 in Scotland, as a % of 1986 Value, 1981 to 2000

0%

20%

40%

60%

80%

100%

120%

1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

insured category population best rate worst rate

Trends in incidence rate of first heart attack for females aged 40 to 64 in Scotland, per 100000 of Population, 1981 to 2000

0

200

400

600

800

1000

1200

1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000


Trends in incidence rate of first heart attack for females aged 40 to 64 in Scotland, as a % of 1986 Value, 1981 to 2000

0%

20%

40%

60%

80%

100%

120%

1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

insured category population best rate worst rate

Summary of heart attack trends by deprivation class

Log-linear improvements (% per annum) in mortality and incidence,for males and females aged 40-64, of acute myocardial infarction in Scotland, 1986 to 2000*

Deprivation category Mortality Incidence Mortality Incidence

1 7.4% 4.8% 7.1% 6.8%2 9.1% 4.2% 9.4% 5.5%3 7.6% 3.2% 8.2% 4.4%4 7.4% 3.4% 7.7% 4.0%5 7.4% 4.2% 7.8% 3.6%6 6.6% 3.7% 7.3% 3.8%7 6.8% 5.8% 5.8% 5.9%

all categories 7.5% 4.5% 7.5% 4.8%insured (categories 1 to 3) 8.0% 3.7% 8.4% 5.0%

*Source: Scottish Health and Registrar General Scotland

Males Females

Summary of heart attack trends by deprivation class, Males aged 40 to 64, 1986 to 2000

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

8.0%

9.0%

10.0%

1 2 3 4 5 6 7

Deprivation Category

Lo

g-l

inear

imp

rovem

en

t %

per

an

nu

m

Mortality Incidence

Summary of heart attack trends by deprivation class, Males aged 40 to 64, 1986 to 2000

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

8.0%

9.0%

10.0%

1 2 3 4 5 6 7


Lo

g-l

inea

r im

pro

vem

ent

% p

er a

nn

um

Mortality Incidence

Brief interpretation of heart attack trends

Male Female

Mortality Positive correlation between affluent and deprived groups

Positive correlation between affluent and deprived groups

Incidence Less clear. Weak negative correlation where deprived group has higher improvement

Postive correlation between affluent and deprived groups except for categories 6 and 7



Heart attack Stroke

Conclusion

Trends in incidence rate of first stroke for males aged 40 to 64 in Scotland, as a % of 1981 value, 1981 to 2000

60%

70%

80%

90%

100%

110%

120%

130%

140%

150%

160%

170%

180%

190%

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

0-39 40-64 65+


60%

70%

80%

90%

100%

110%

120%

130%

140%

150%

160%

170%

180%

190%

200%

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

40-64


60%

80%

100%

120%

140%

160%

180%

200%

1981 1983 1985 1987 1989 1991 1993 1995 1997 1999

1 2 3 4 5 6 7 overall

Trends in incidence rate of first stroke for males aged 40 to 64 in Scotland, per 100000 of Population, 1981 to 2000

0

100

200

300

400

500

600

700

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

1 2 3 4 5 6 7 9

Trends in incidence rate of first stroke for males aged 40 to 64 in Scotland, per 100000 of Population, 1986 to 2000

0

100

200

300

400

500

600

700

1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000


Trends in incidence rate of first stroke for females aged 40 to 64 in Scotland, per 100000 of Population, 1986 to 2000

0

100

200

300

400

500

600

700

1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000


Trends in mortality rate by stroke for males aged 40 to 64 in Scotland, per 100000 of Population, 1986 to 2000

0

20

40

60

80

100

120

140

1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000


Trends in mortality rate by stroke for females aged 40 to 64 in Scotland, per 100000 of Population, 1986 to 2000

0

20

40

60

80

100

120

140

1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000


Summary of stroke trends by deprivation class

Log-linear improvements (% per annum) in mortality and incidence,for males and females aged 40-64, of stroke in Scotland, 1986 to 2000*

Deprivation category Mortality Incidence Mortality Incidence

1 5.3% -1.2% 3.1% -2.0%2 4.5% -1.2% 5.1% -2.0%3 3.7% -2.6% 4.1% -1.9%4 4.2% -3.4% 5.4% -2.3%5 4.4% -2.7% 4.1% -2.4%6 2.9% -2.7% 3.9% -2.2%7 3.6% -1.2% 6.5% 0.1%

all categories 4.0% -1.9% 4.7% -1.5%insured (categories 1 to 3) 4.1% -2.0% 4.3% -1.9%

Males Females

Summary of stroke trends by deprivation class, Males aged 40 to 64, 1986 to 2000

-4.0%

-3.0%

-2.0%

-1.0%

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

1 2 3 4 5 6 7


Lo

g-l

inear

imp

rovem

en

t %

per

an

nu

m

Mortality Incidence

Summary of stroke trends by deprivation class, Females aged 40 to 64, 1986 to 2000

-3.0%

-2.0%

-1.0%

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

1 2 3 4 5 6 7


Lo

g-l

inear

imp

rovem

en

t %

per

an

nu

m

Mortality Incidence

Brief interpretation of stroke trends

Male Female

Mortality Positive correlation between affluent and

deprived groups

Weak negative correlation between

affluent and deprived groups

Incidence Weak positive correlation between


Weak postive correlation between


Contents Slide


Variation by ICD code

Why? Understanding of overall rate Explain which components have influenced overall trend

Heart attack ICD9 code 410 Unstable angina ICD9 code 413

Stroke ICD9 codes 430 to 437 excluding 435

Trend in first incidence rate for males aged 40 to 64 by ICD code 410 and 413, per 100000 of Population, 1981 to 2000

0

100

200

300

400

500

600

700

800

900

410 (Heart attack) 413 (Unstable Angina)

Trend in first incidence rate for females aged 40 to 64 by ICD code 410 and 413, per 100000 of Population, 1981 to 2000

0

100

200

300

400

500

600

700

800

900

410 (Heart attack) 413 (Unstable Angina)

Variation by ICD code

Why? Understanding of overall rate Explain which components have influenced overall trend

Heart attack ICD9 code 410 Unstable angina ICD9 code 413

Stroke ICD9 codes 430 to 437 excluding 435

Trend in first incidence rate for males aged 40 to 64 by ICD codes 430 to 437 excluding 435, per 100000 of Population,

1981 to 2000

0

50

100

150

200

250

300

350

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

year

Rate

of

Incid

en

ce p

er

100,0

00 o

f p

op

ula

tio

n

430-437 excluding 435

Trend in first incidence rate for males aged 40 to 64 by ICD codes 430 to 437 excluding 435, 1981 to 2000

0

50

100

150

200

250

300

350

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

year

Inci

den

ce r

ate

per

100

,000

of

po

pu

lati

on

430 431 432 433 434 436 (Acute stroke) 437

Trend in first incidence rate for females aged 40 to 64 by ICD code 430 to 437 excluding 435, per 100000 of Population,

1981 to 2000

0

50

100

150

200

250

300

350

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

year

Rate

of

Incid

en

ce p

er

100,0

00 o

f p

op

ula

tio

n

430-437 excluding 435

Trend in first incidence rate for females aged 40 to 64 by ICD code 430 to 437 excluding 435, per 100000 of Population,

1981 to 2000

0

50

100

150

200

250

300

350

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

year

Incid

en

ce r

ate

per

100,0

00 o

f p

op

ula

tio

n

430 431 432 433 434 436 (Acute stroke) 437

Summary of variation by ICD code

Heart attack: ICD 410 is improving over time (Male 3.6% p.a., Female 3.3%) ICD 413 is deteriorating (Male 5.2% p.a., Female 6.2% p.a.) Troponins?

Stroke Large component ICD 436 is improving over time (Male 5.2% p.a.,

Female 6.2%) Remaining components ICD 430, 431,432,433, 434, 437 overall are

deteriorating over time (Male 5.7% p.a., Female 4.3% p.a.) Overall deterioration (Male 1.9%, Female 1.5%) Overall flat trend over 1980’s, deterioration over 1990’s Future?

Contents Slide


Contents Slide

Introduction

Variations by deprivation category

Variations by ICD code

Impact of smoking

Future influences on rates

Projecting population incidence rates

Impact of Smoking - “Ideal” Smoking Model

ix (pop) = ix(ns)* p(ns) + ix (s) * p(s) +ix(ex) * p(ex)

ix (pop) = ix(ns)* p(ns) + ix (s) * p(s) + t ix(ex t) * p(ex t)

…..

…..

Impact of Smoking - Data Available

Epidemiological evidence on smoking Case control studies, prospective cohort studies etc

Wide range of results results become even more volatile if looking for age specific or

duration smoked/quit specific results

often look at impact on mortality not incidence

cause investigated is often not an exact match e.g. coronary heart disease and not acute myocardial infarction

usually smoking status is only investigated at the start of the study period

Simplify and/or use proxies

Impact of Smoking -Smoking Model

Age specific model

ix (pop) = ix(ns)* propx (ns) + ix (ns) * RRx *propx (s)

assumes that people move immediately from being a

smoker to a never smoker

Ex-smoker model

ix(pop) = ix(ns) *propx(ns) + ix(ns) * RR1 *propx (ex1) +…

…….+ ix(ns) *RR(sm) propx(s)

assumes that the relative risks for smokers and ex-smokers

are independent of age

Impact of Smoking - Males

AMI(first ever &subsequent)

AMI(firstever)

CABG CABG('94-'99)

Angioplasty2+

Stroke Combined

Per annum % change betweenthe years 1989 and 1999

-1.5% -1.0% 7.8% 1.1% 13.4% 2.9% 1.5%

Exponential model - % change inthe inception rate from 1989 to1999Population -1.7% -0.4% 7.7% 1.9% 11.5% 3.1% 1.4%

Smoker model age specificrelative risks

-1.2% -0.1% 8.3% 2.2% 12.1% 3.5% 2.0%

Smoker model allowing for ex-smokers

-1.2% 0.1% 8.2% 2.4% 12.0% 3.5% 1.9%

Trends in Coronary Artery Bypass Incidence All Ages Combined

80%

130%

180%

230%

280%

330%

89/89 90/89 91/89 92/89 93/89 94/89 95/89 96/89 97/89 98/89 99/89

Females

Males

Impact of Smoking - Females

AMI(first ever &subsequent)

AMI(firstever)

CABG CABG('94-'99)

Angioplasty2+

Stroke Combined

Per annum % change betweenthe years 1989 and 1999

-1.7% -1.2% 10.7% 2.5% 16.3% 2.5% 1.2%

Exponential model - % change inthe inception rate from 1989 to1999Population -2.0% -0.6% 10.5% 3.0% 14.0% 2.7% 1.3%

Smoker model age specificrelative risks

-1.8% -0.3% 10.7% 3.2% 14.2% 2.9% 1.5%

Smoker model allowing for ex-smokers

-1.8% -0.2% 10.7% 3.4% 14.2% 2.9% 1.4%

Males - Trends in AMI (first and subsequent) 1989-1999 Percentage Change p.a.

-5%

-4%

-3%

-2%

-1%

0%

1%

2%

3%

4%

5%

25_29 35_39 45_49 55_59 65_69 75_79 85_89

Females - Trends in AMI (first and subsequent) 1989-1999 Percentage Change p.a.

-5%

-4%

-3%

-2%

-1%

0%

1%

2%

3%

4%

5%

25_29 35_39 45_49 55_59 65_69 75_79 85_89

Contents Slide

Introduction



Impact of smoking



Future Influences on Rates

Impact of changing risk factors on incidence

Focus on changes in diagnostic techniques and

potential shocks in incidence

Discussion of impact of troponin on heart attack

incidence

Interpreting trends in stroke incidence and the

potential impact of brain imaging techniques

Troponin and Acute Coronary Syndrome

Number of medical papers available

Generally look at the change in the number of

diagnoses in the spectrum of ACS

Spectrum of Acute Coronary Syndromes

K Fox., Heart; 2000;84;93-100


As might be expected sample sizes quite small

Definitions do not exactly match those used by the

insurance industry

Average age is considerably higher than that of

people who claim for critical illness

Number of medical papers available

Generally look at the change in the number of

diagnoses in the spectrum of ACS


Study Patients Results

Monklands Hospital Every admission to Monklandsbetween April 1997 and Dec 20001671 AMI on WHO definition

Female +70% Male +50%

Northern Lincolnshire and GooleHospitals

Retrospective audit patientsadmitted Jan-June 2000 (61 AMI)and a prospective cohort Jan - June2001(176 AMI)

Increase in MI of +188%

Coventry and Warwick Hospitals All patients admitted with cardiacchest pain (401) 119 AMI on WHO

Increase in MI of 35% using TnC

Norway 442 patients admitted withsuspected acute coronarysyndrome tCK used as the goldstandard 172 AMI

CK MB>6 mcg/l +29%, Ctn1>1mcg/l 37%

Norway 337 patients suspected acutecoronary syndrome 94 patients CKMB >5 mcg 108 patients TnT > 0.1mcg/l

UK District Hospital 663 patients with suspected acutecoronary syndrome

Using cTnT, AMI increased by+55%, ruled out 3%

Royal Infirmary of Edinburgh 80 patients with suspected ACSexcluding those where the ECGindicated definite AMI

40% of these confirmed AMI usingcTnT compared to 29% usingconventional diagnostic techniques

Troponin and Critical Illness

Medical studies give a range of results

Results need careful interpretation before trying to apply

them to critical illness

More AMI being diagnosed but some an acceleration e.g.

subsequent heart attack

coronary artery bypass surgery

Troponin and Critical Illness

Percentage of hospitals where troponin is available

Scotland - 70% (Pell BMJ Vol 324)

England - 60% last year thought to be 70% to 80% this year

No clear consensus amongst cardiologists in the UK on

the definition

New definition not disseminated until September 2000 so

no effect on the data currently published

Trends in Heart Attack Incidence All Ages Combined

80%

85%

90%

95%

100%

105%

89/89 90/89 91/89 92/89 93/89 94/89 95/89 96/89 97/89 98/89 99/89

Females

Males

Stroke - Identifying Trends

“Stroke mortality is falling in many countries, but it is unclear whether this is due to a fall in stroke incidence, lower case fatality, or some artifact of the collection and analysis of routine mortality data.”

Stroke, A Practical Guide and Management. Warlow et al

Stroke - Identifying Trends

“In the few places where it has been measured reasonably reliably, stroke incidence seems to have declined, stayed the same, or increased. However it has been very difficult to use consistent methods and obtain large enough data sizes for precise estimates. In truth it is not very clear what incidence rates are doing.”

Stroke, A Practical Guide and Management. Warlow et al

Stroke - HES Data

Patients admitted to hospital generally have more severe strokes

The proportion of all strokes admitted is unknown and

can change over time

Cannot identify first ever strokes

Double counting as patients move from one hospital

service to another

Question mark over change in incidence coinciding with

coding change

Trends in Stroke Incidence All Ages Combined

80%

90%

100%

110%

120%

130%

140%

89/89 90/89 91/89 92/89 93/89 94/89 95/89 96/89 97/89 98/89 99/89

Females

Males

Stroke - Diagnosis

ABI definition of stroke is different to that used by

clinicians and to that used by the WHO

Consequences of, for example, increased MRI scanning

could have a different impact under different definitions

Will policyholders understand the differences?

Milder strokes more often identified?

Patient expectations are rising

Diagnostically more competent

Helped by more sensitive brain imaging

Contents Slide

Introduction



Impact of smoking



Population - Projection of Incidence Rates

AMI, CABG, Angio2+ and Stroke

Past TrendsContinue

With Shock for AMI

Males

Population 1.6% 2.4%

Age specific model 2.1% 2.8%

Ex-smoker model 2.1% 2.8%

Females

Population 1.7% 2.3%

Age specific model 2.2% 2.8%

Ex-smoker model 2.0% 2.6%

the 2002 healthcare conference 29 september-1 october 2002 scarman house, the university of warwick,...

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deprivation classwhy

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underlying trends

categories overall trends

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historic trend

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