Mortality trends in type 2 diabetes mellitus patients in a primary care setting

1994 to 2011

Jelske Dekkers6th year medical student

• Introduction

• Research question

• Patients and methods

• Results• Sociodemographic characteristics

• Mortality rates

• Clinical patient characteristics

• Survival analysis

• Conclusion

• Discussion

• References

Introduction – Diabetes mellitus

• Diabetes mellitus• Type 1

• Type 2 90%

• Prevalence

• 2003:

• Men 36/1000

• Women 39/1000

• 2007

• Men 40.1/1000

• Women 41.6/1000

Introduction – Type 2 diabetes

• Causes• Betacel dysfunction inadequate production of insulin

• Insulin resistance

• Associations• Hypertension

• Obesity Metabolic syndrome or syndrome X

• Hypercholesteromia

• Complications• Cardiovascular disease 2-4 times increased risk of CVD associated death

• Renal disease

• Retinal disease

• Polyneuropathy

Research question

• What is the trend in mortality rates of type 2 diabetes patients compared to the mortality rates of the general Dutch population from 1994 to 2011?

• Is there a difference in clinical characteristics of type 2 diabetes patients from 1994 to 2011?

Patients and methods

• All type 2 diabetes patients in the NMP/HIS database between 1994 and 2011

• NMP/HIS database • Database of all patients with chronic illnesses treated (partially)

in 9 primary care practices

• Includes clinical patients characteristics from every check up

Patients

Patients with type 2 diabetes (partially) treated in primary care, 1994-2011

N = 3748Patients with type 2

diabetes, not treated in primary care

N = 297

Patients with type 2 diabetesN = 4045

Patients with type 2 diabetes with a known date

of diagnosisN = 4014

Patients without a known date of diagnosis

N = 31

Methods; database

Methods – Mortality rates

• Mortality rates type 2 diabetes patients for each year• All patients

• Men

• Women

• Comparison group: general Dutch population, adjusted for age, using CBS Statline Database• Complete population

• Men

• Women

Methods – Clinical patient characteristics

• Bloodpressure

• Body mass index

• HbA1c

• Total cholesterol

• HDL

• Calculated for 1996, 2001, 2006 and 2011

• Clinical characteristics of the patients in the NMP/HIS database only patients (partially) treated in primary care

Results – Sociodemographic characteristics

All patients 1996N = 794

2001N = 1291

2006N = 1917

2011N = 2803

Mean age 65.3(64.4-66.2)

63.3(62.5-64.6)

63.8(63.2-64.6)

65.6(65.1-66.1)

Mean age at diagnosis

59.3(58.4-60.2)

57.9(57.2-58.6)

57.3(56.7-57.9)

57.9(57.4-58.4)

Mean duration of disease in years

6.1(5.7-6.5)

5.7(5.4-6.0)

6.6(6.3-6.9)

7.8(7.6-8.0)

Results – Sociodemographic characteristics, men and women

1996 2001 2006 2011

Mean age men 62.4(61.0-63.8)

60.9(59.9-61.9)

62.4(61.6-63.2)

64.4(63.8-65.0)

Mean age women

67.5(66.3-68.7)

66.2(65.2-67.2)

65.3(64.4-66.2)

67.0(66.3-67.7)

Mean age at diagnosis men

57.0 (55.6-58.4)

55.8(54.8-56.8)

56.2(55.4-57.0)

56.8(56.2-57.4)

Mean age at diagnosis women

61.1(58.9-62.3)

59.9(59.0-60.8)

58.3(57.5-59.1)

59.0(58.3-59.7)

Mean duration of disease in years men

5.6(5.0-6.2)

5.2(4.8-5.6)

6.2(5.8-6.6)

7.6(7.3-7.9)

Mean duration of disease in years women

6.4(5.9-6.9)

6.3(5.9-6.7)

6.9(6.5-7.3)

8.0(7.6-8.4)

Results; mortality

1996 2001 2006 2011

All 794 1291 1917 2803

Deceased 36 37 47 76

Men 349 619 968 1444

Deceased 20 15 20 44

Women 445 672 949 1359

Deceased 16 22 27 32

Mortality rates in comparison to the Dutch population

Year Mortality rate diabetic patients in % (95% CI)

Adjusted mortality rate general population in %

Mortality rate diabetic men in %(95% CI)

Adjusted mortality rate men general population in %

Mortality rate diabetic women in %(95% CI)

Adjusted mortality rate women general population in %

1994 4.9(3.3-6.5)

3.2 4.4(2.0-6.8)

3.2 5.2(3.0-7.4)

3.1

1995 2.6(1.4-3.8)

3.1 2.2(0.6-3.8)

3.6 2.9(1.3-4.5)

3.0

1996 4.5(3.1-5.9)

3.0 5.7(3.3-8.1)

3.3 3.6(1.9-5.3)

3.1

1997 4.8(3.4-6.2)

3.2 5.6(3.3-7.9)

3.4 4.2(2.4-6.0)

3.0

1998 4.7(3.3-6.1)

2.7 4.4(2.4-6.4)

3.1 5.0(3.1-6.9)

3.0

1999 4.5(3.2-5.8)

2.9 4.0(2.2-6.8)

2.9 5.0(3.2-6.8)

2.9

2000 3.0(2.0-4.0)

2.7 2.7(1.4-4.0)

3.1 3.3(1.9-4.7)

2.8

2001 2.9(2.0-3.8)

2.5 2.4(1.2-3.6)

2.3 3.3(1.9-4.7)

2.5

2002 2.9(2.0-3.8)

2.6 2.9(1.6-4.2)

2.4 2.8(1.6-4.0)

2.7

Mortaliy rates – 2

2003 2.6(1.8-3.4)

2.5 2.6(1.4-3.8)

2.4 2.5(1.4-2.6)

2.6

2004 2.1(1.4-2.8)

2.4 1.7(0.8-2.5)

2.3 2.4(1.4-3.4)

2.5

2005 3.3(2.5-4.1)

2.5 3.0(1.9-4.1)

2.4 3.5(2.3-4.7)

2.6

2006 2.5(1.8-3.2)

2.3 2.1(1.2-3.0)

2.4 2.8(1.8-3.8)

2.3

2007 3.2(2.4-4.0)

2.3 3.2(2.1-4.3)

2.4 3.2(2.1-4.3)

2.3

2008 2.7(2.0-3.4)

2.3 2.6(1.7-3.5)

2.3 2.7(1.7-3.7)

2.3

2009 2.7(2.1-3.3)

2.3 2.2(1.4-3.0)

2.3 3.3(2.3-4.3)

2.3

2010 2.1 (1.6-2.6)

2.3 2.8(1.7-3.9)

2.3 1.4(0.6-2.0)

2.4

2011 2.7(2.1-3.3)

2.4 3.0(2.1-3.9)

2.3 2.4(1.6-3.2)

2.5

Year Mortality rate diabetic patients in % (95% CI)

Adjusted mortality rate general population in %

Mortality rate diabetic men in %(95% CI)

Adjusted mortality rate men general population in %

Mortality rate diabetic women in %(95% CI)

Adjusted mortality rate women general population in %

Mortality figures – all patients

Mortality figures – men

Mortality figures - women

Clinical patient characteristics

1996 2001 2006 2011

Mean systolic bloodpressure

151,2(149.4-153.0)N = 568

148.4(147.3-149.5)N = 954

143.9(143.0-144.8)N = 1479

139.8(139.2 – 140.4)N = 2279

Mean diastolic bloodpressure

83.7(82.9-84.5)N = 567

82.3(81.7-82.9)N = 954

80.8(80.3-81.3)N = 1473

78.6(78.2-79.0)N = 2277

Mean body mass index

28.6(28.2 – 29.0)N = 544

29.3(29.0 – 29.6)N = 923

29.7(29.4 – 30.0)N = 1375

30.1(29.9 – 30.3)N = 2121

Mean HbA1 c 55.3(53.4 – 57.2)N = 362

54.5(53.5 – 55.5)N = 662

53.4(52.7 – 54.0)N = 1191

53.5(53.0 – 54.0)N = 2238

Mean total cholesterol

6.10(5.98 – 6.22)N = 418

5.38(5.30 – 5.46)N = 764

4.88(4.81 – 4.95)N = 1089

4.53(4.48 – 4.58)N = 2156

Kaplan Meier survival analysis

Kaplan Meier Survival analysis; men and women

Conclusion

• Mortality rates declined between 1994 and 2011

• Since 2000 there is no difference in mortality

• In 2010 diabetic women had a lower mortality rate

• The mean bloodpressure and cholesterollevel have decreased significantly from 1996 to 2011

• In our study population 50% of all type 2 diabetics would still be alive 20 years after diagnosis

• The first 20 years after diagnosis women have a better survival probability than men

• After 20 years, men have a better survival

Discussion

• Strengths• Large NMP/HIS database with sociodemographic and clinical

patient characteristics of the majority of our study population

• Comparison group: complete Dutch population

• Weaknesses• No clinical patient characteristics of patients who weren’t treated in

primary care possible underestimation of clinical characteristics

• Transsition from NMP to HIS as primary source of information in 2006-2008 voids in yearly check ups and information

• Second hand information

• Only all cause mortality, no information about cardiovascular associated deaths

Discussion

• Other studies on this subject• Mortality rates of type 2 diabetes patients are declining

• Relative mortality risk compared to control group is declining

• Most studies still found a signifant difference between mortality rates of diabetics and non-diabetics

• Greater study population

• Earlier period

• Other health care systems

• Follow up study

• Correlation between declining mortality rates and declining bloodpressure and cholesterol

• Clinical characteristics of all type 2 diabetes patients, including those of patients not treated in primary care

Questions or other discussion points?

References

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• www.nationaalkompas.nl