Predictors of 5-year mortality of 1,323 patients newly diagnosed with clinical

type 2 diabetes in general practiceWith special emphasis on self-rated health

Niels de Fine OlivariusVolkert Siersma

Anni B. S. NielsenLars J. Hansen

Lotte RosenvingeCarl Erik Mogensen

Important predictors of mortality in type 2 diabetic patients

• Age• Sex• Blood glucose level• Blood pressure• Lipids• Urinary albumin excretion• Smoking• Cardiovascular disease

Self-rated general health (SRH)

Question to patients:"In general, how would you rate your health at present?" Excellent Good Fair Poor Very poor

Implications of SRH

In the general population SRH predicts both future morbidity such as ischaemic heart disease and mortality independently of

established risk indicators,

but evidence of this is scarce for people with diabetes

Aim of the study

To investigate the contribution to 5-year all-cause and cardiovascular mortality of the

characteristics found at the more or less acute state at diabetes diagnosis.

In particular, we evaluated the possible independent effect of SRH on mortality.

Flow

cha

rtInclusion criteria:1) Diabetes mellitus diagnosed from 1 March 1989 to 28 February 19922) Whole blood or plasma glucose concentration ≥ 7.0/8.0 mmol/l

measured at a major laboratory3) Age 40 years or older

Eligible patients, n=1,543

Primary exclusions:Severe somatic disease, n=50Severe mental illness, n=50Declined to consent, n=62

Analysed, n=1,323

Secondary exclusions:Steroid treatment at diagnosis, n=46Non-white ethnicity, n=12

Available patient sample, n=1,381

Outcome variables

From the Danish National Death Register:• All-cause mortality• Cardiovascular mortality

Median observation time: 5.2 yearsNumber of deaths: 298

Baseline predictor variables

SexAgeLiving aloneEducationDiagnostic plasma glucoseFasting triglycerideTotal cholesterolUrinary albuminBody mass index

Resting heart rateSystolic blood pressurePhysical activitySmokingSelf-rated healthCardiovascular diseaseDiabetic retinopathyPeripheral neuropathyCancer (former or present)

Statistical analysisPredictors of 5-year mortality

The influence on all-cause and cardiovascular mortality of patient characteristics measured at diabetes diagnosis was investigated in Cox proportional hazard models. In these models the death intensity was represented as a function of patient age, multiplicatively affected by the characteristics.

Predictors of 5-year mortalityCox regression analyses

* p<0.05 ** p<0.01 *** p<0.001

Estimated life expectancy according to predictors at diagnosis. Men only

Values are median life expectancy according to baseline characteristics calculated from a Cox model which includes all baseline characteristics. The other faxtors in the model are kept fixed.

Implications 1 – the easy part

In newly diagnosed diabetic patients: be attentive to patients who are/have

- Relatively young- Inactive- Cardiovascular disease- (Micro)albuminuria

What does SRH measure?

SRH ≈ A personal estimation of longevity?… taking into account

- Current and previous health

- Symptom perception

- Personal resources

- Physical functioning

- Health behaviour

- Comparison with age peers

- Familial disposition

The SRH hypothesis

SRH primarily carries risk information which cannot be uncovered by

present-day technology, and

this information has to a considerable degree a biological basis

A question from a colleague

Non-excellent SRH Increased mortality

“Does it mean that GPs can concentrate on making the patients feel content and happy about their lives and not worry so much about blood glucose, blood pressure and

lipids”

?

Implications 2 - SRH

This finding could motivate general practitioners and practice nurses to discuss perceptions of health with newly diagnosed diabetic patients and be attentive to patients with

suboptimal health ratings

Non-excellent SRH Increased mortality

The problem of frailty

Frailty ≈ Heterogeneity among our patients in their susceptibility to dying

Undiagnosed or even unascertainable conditions may have contributed to precipitate the diabetes diagnosis,

and these conditions may be associated with both poor SRH or low physical activity and high risk of death.

Approaching heterogeneity

• Sub-group analysis of "healthy" patients (n=696) without CVD, diabetic retinopathy, peripheral neuropathy, cancer and proteinuria

• Analysis of deaths occurring within 3 years of diabetes diagnosis (n=153) and after this time (n=145)

• Analyses excluding deaths occurring within 6 months of diabetes diagnosis (n=25)

Predictors of 5-year all-cause mortalityCox regression analysis

Bold: p<0.05

The excess mortality of type 2 diabetic patients

Prop

ortio

n of

sur

vivo

rs

Years since diabetes diagnosis

80+ years

60-79 years

40-59 years

The Danishpopulation

Patients withnewly diagnoseddiabetes

Men