Coronary heart disease trends in England and Wales from

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					     Coronary heart disease trends
      in England and Wales from
        1984 to 2004: concealed
       levelling of mortality rates
          among young adults.
M. O’Flaherty1, E. Ford2, S. Allender3, P. Scarborough3, S.
Capewell1
1Division of Public Health, University of Liverpool, Liverpool, UK
2 Division of Adult and Community Health, National Centre for
Chronic Disease Prevention and Health Promotion, Centres for
Disease Control and Prevention, Atlanta, GA, USA
3 BHF Health Promotion Research Group, Division of Public Health
and Primary Health Care, University of Oxford, Oxford, UK.

                           Heart. 2007
             CHD Mortality: Trends

• Downward trend since 1960 in the UK
    Reflect changes in population risk factors and
     also treatments.
    Still the leading cause of death.

• Concern has recently been expressed that in the
  USA the rate of decline in CHD mortality has slowed
  during the 1990s compared to earlier decades.

(Cooper R et al Circulation 2006; 102[25], 3137)
Might falls in CHD death rates be
blunted by recent increases in UK
      in risk factor levels?
 Increases in obesity and diabetes since 1980s

 Small declines in total cholesterol
  concentrations during the 1990s have been
  modest (prescribing of statins has escalated)

 Adult prevalence of smoking still is 25%

 Totally sedentary UK adults during leisure-time
  has probably increased since the 1990s
      Change in trends in risk factors
      seems particularly worrying in
              young adults
• Between 1993 and 2003 the largest relative increases
  in obesity and diabetes have occurred among adults
  aged less than 45 years



• Cholesterol changed little or increased among some
  younger age groups


• The previous decline in smoking rates may be
  leveling off among young adults
  Study aim: To examine trends in
     the age-specific rates for
 coronary heart disease among UK
       adults from 1984-2004

• Reasonable to hypothesize that adverse trends
  in CHD mortality rates may be detected first
  among young adults.


• Trends in age-specific rates have received little
  attention, previous reports have emphasized the
  continuing declines in the age-adjusted CHD
  mortality rate among UK adults.

• Age adjusted rates may conceal important
  phenomenon occuring within age groups
                       Methods
• Period 1984-2004
    CHD deaths (ONS) :
       • ICD-9 codes 410-414 for 1984-1998
       • ICD-10 codes I20-I25 for 1999-2004
    Censal and intercensal estimates for population
     figures (ONS)

• Direct age-adjusted rates using 2001 as standard

• A joinpoint regression was fitted to detect points in
  time where significant changes in the trends
  occurred
• It provides estimated annual percentage change
  (EAPC) in rates and 95% confidence intervals,
      Results: UK 1984-2004
Decline in overall age-adjusted CHD
            mortality rate
                     900.00
                                            2.7% per year (rate of decline)
                     800.00

                     700.00                                                                  3.7%
CHD rates per 10^6




                     600.00
                                                                                                                                                 5.4%
                     500.00
                                            1.7%                                                                                                                     men
                     400.00
                                                                                             3.5%
                     300.00

                     200.00                                                                                                                     4.2%                 women

                     100.00

                       0.00
                              1984

                                     1985

                                            1986

                                                   1987

                                                          1988

                                                                 1989

                                                                        1990

                                                                               1991

                                                                                      1992

                                                                                              1993

                                                                                                      1994

                                                                                                             1995

                                                                                                                    1996

                                                                                                                           1997

                                                                                                                                  1998

                                                                                                                                         1999

                                                                                                                                                2000

                                                                                                                                                       2001

                                                                                                                                                              2002

                                                                                                                                                                     2003

                                                                                                                                                                            2004
                                                                                                     year
                                   UK 1984-2004
                           Age-specific CHD mortality rate

                         10000



                         1000
rates 10^6 (log scale)




                          100



                           10



                            1
                                 1984

                                        1986


                                               1988

                                                       1990


                                                              1992

                                                                     1994

                                                                            1996


                                                                                   1998

                                                                                          2000

                                                                                                 2002

                                                                                                        2004



                                                                                                               1984


                                                                                                                      1986


                                                                                                                             1988


                                                                                                                                    1990


                                                                                                                                           1992


                                                                                                                                                  1994


                                                                                                                                                         1996


                                                                                                                                                                1998


                                                                                                                                                                       2000


                                                                                                                                                                              2002


                                                                                                                                                                                     2004
                                                      men                                                                                  women

                                                      Dotted line: observed rates. Continuos lines: 5 year moving average
        Joinpoint regression explained
• The software takes trend data (e.g cancer rates) and fits the
  simplest joinpoint model that the data allow.

• The program starts with the minimum number of joinpoint (e.g.
  0 joinpoints, which is a straight line) and tests whether more
  joinpoints are statistically significant and must be added to the
  model (up to a maximum number).

• This enables the user to test that an apparent change in trend
  is statistically significant. The tests of significance use a Monte
  Carlo Permutation method.

• The models may incorporate estimated variation for each point
  (e.g. when the responses are age adjusted rates) or use a
  Poisson model of variation.

• In addition, the models may also be linear on the log of the
  response (e.g. for calculating annual percentage rate change).
    Joinpoint regression: example


Men 45-54:
• 4 periods identified
• annual percent change
  decreases at the end of the
  20 years period




 Men 65-54:
  3 periods identified
  annual percent change
   continually increase
       75+
                                  65-74
                                                               55-64
                                                                                                                           35-44




                                                                                               45-54




                                                         -9
                                                              -8
                                                              -7
                                                              -6
                                                              -5
                                                                   -4
                                                                   -3
                                                                   -2
                                                                        -1




                                                        -10
                                                                         0
                                                                                                                -10
                                                                                                                 -9
                                                                                                                      -8
                                                                                                                      -7
                                                                                                                      -6
                                                                                                                      -5
                                                                                                                           -4
                                                                                                                           -3
                                                                                                                           -2
                                                                                                                                -1
                                                                                                                                 0




                                                                                    -10
                                                                                     -9
                                                                                          -8
                                                                                          -7
                                                                                          -6
                                                                                          -5
                                                                                               -4
                                                                                               -3
                                                                                               -2
                                                                                                    -1
                                                                                                     0




                             -9
                                  -8
                                  -7
                                  -6
                                  -5
                                       -4
                                       -3
                                       -2
                                            -1




                            -10
                                             0




 -9
      -8
      -7
      -6
      -5
           -4
           -3
           -2
                -1




-10
                 0
                     1984                        1984                        1984                        1984                        1984


                     1986                        1986                        1986                        1986                        1986


                     1988                        1988                        1988                        1988                        1988


                     1990                        1990                        1990                        1990                        1990


                     1992                        1992                        1992                        1992                        1992


                     1994                        1994                        1994                        1994                        1994


                                                 1996                        1996                        1996                        1996
                     1996
                                                                                                                                                           (men)




                                                 1998                        1998                        1998                        1998
                     1998


                                                 2000                        2000                        2000                        2000
                     2000


                                                 2002                        2002                        2002                        2002
                     2002


                                                 2004                        2004                        2004                        2004
                     2004
                                                                                                                                             CHD mortality rates, UK 1984-2004
                                                                                                                                            Estimated Annual Percent change in
                75+
                                                 65-74
                                                                                55-64
                                                                                                                                                                      35-44




                                                                                                                       45-54




-6
     -5
          -4
               -3
                    -2
                         -1
                              0
                                  1
                                      2
                                                 -9
                                                 -8
                                                 -7
                                                 -6
                                                 -5
                                                 -4
                                                 -3
                                                 -2
                                                 -1
                                                  0
                                                                -10
                                                                      -8
                                                                           -6
                                                                                 -4
                                                                                      -2
                                                                                           0
                                                                                                                                           -3.5
                                                                                                                                                       -2.5
                                                                                                                                                                   -1.5
                                                                                                                                                                               -0.5




                                                                                                                                                  -3
                                                                                                                                                              -2
                                                                                                                                                                          -1
                                                                                                                                                                                      0




                                                                                                      -10
                                                                                                            -8
                                                                                                                 -6
                                                                                                                      -4
                                                                                                                           -2
                                                                                                                                0




                                          1984           1984
                                                                                               1984                                 1984                                                  1984

                                          1986           1986
                                                                                               1986                                 1986                                                  1986

                                          1988           1988
                                                                                               1988                                 1988                                                  1988


                                          1990           1990                                  1990                                 1990                                                  1990


                                          1992           1992                                  1992                                 1992                                                  1992


                                          1994           1994                                  1994                                 1994                                                  1994


                                          1996           1996                                  1996                                 1996                                                  1996


                                          1998           1998                                  1998                                 1998                                                  1998


                                          2000           2000                                  2000                                 2000                                                  2000


                                          2002           2002                                  2002                                 2002                                                  2002


                                          2004           2004                                  2004                                 2004                                                  2004
                                                                                                                                                                                                          2004 (women)
                                                                                                                                                                                                  in CHD mortality rates, UK 1984-
                                                                                                                                                                                                 Estimated Annual Percent change
                        Conclusions
• The previous falls in age-specific CHD mortality rates appear to
  be flattening in men and women aged under 55 years.

• Rates in older adults continue to decline at the same pace.
• These trends have occurred in spite of the increasing use of
  evidence-based therapies (such as angioplasty, thrombolysis
  and angiotensin-converting enzyme inhibitors.)

• Hypothesis:
    Unfavorable recent trends in risk factors in susceptible
     young adults may explain these changes:
      • specifically increases in obesity and diabetes
        compounded by stable cholesterol levels and a 25%
        smoking prevalence

• We need to further explore these issues by relating trends in
  mortality and risk factors.